Method for debittering brewer's yeasts and debittered products obtained

Abstract

The present invention relates to the use of a transition medium and a feed medium for implementing a method for debittering a brewer's yeast from brewery fermentation.

Description

[0001] DescriptionTitle: PROCESS FOR DEBITTERING BREWING YEASTS AND DEBITTERED PRODUCTS OBTAINED Technical field The present invention relates to a process for debittering brewing yeasts resulting from brewing fermentation and the debittered yeasts obtained State of the art In the context of brewing production, approximately 200 billion liters of beer are produced worldwide. Beer production consumes a large amount of natural resources in order to meet the many utilities of the industry (production of steam, cold, agricultural raw materials for example). Furthermore, a general awareness of the environmental impact of food and the production of animal proteins is leading to the development of alternative diets. During brewing fermentation, a surplus of brewing yeast is generated (between 2 and 5g per liter of brewed beer).This is removed from the fermentation tank at various stages (up to three times for some breweries) or during the final filtration / centrifugation of the beer. Brewer's yeast is a widely used ingredient in the alcohol, yeast extract, and bread-making industries. However, its use as a raw ingredient is still limited in the food industry, although it is made up of 40 to 50% protein. These yeasts are linked to bitter molecules related to the brewing process. The main molecules identified so far are: Alpha acids: humulone, cohumulone, adhumulone. Beta acids: Lupulone, colupulone, adlupulone. Isoalpha acids: Isohumulones, isocohumulones, isoadhumulones.

[0002]

[0003] These compounds bind primarily to yeast cell walls. The concentration of these compounds typically depends on their affinity for the cell walls as well as their initial concentration in the brewing wort. It is well known that yeast from beer brewing can be lysed to prepare concentrates of soluble materials derived primarily from the inner cell rather than the cell wall. Bitter substances are removed by first washing the yeast cells with a dilute alkali solution, thus limiting the amount of these substances in the finished product. However, alkaline treatment also removes food compounds of interest by removing proteins and other materials present in brewing yeast, and diminishes the organoleptic quality of the ingredient. Activated carbon has also been used to remove humulones from concentrated lysates, but such treatment suffers from some undesirable characteristics, namelylack of ease of filtration of lysates and the elimination by simultaneous adsorption of food compounds of interest. Also, processes using alkaline suspensions generate significant quantities of water and alkaline solution which are harmful to the environment. The invention aims to address the above problem and to enable the use of brewing yeasts devoid of bitter molecules in the food industry. One aspect of the present invention is the use of brewing yeast derived from brewing fermentation in the implementation of a debittering process. Another aspect of the present invention is the use of co-products from the food industry as a carbon source in a debittering process. Another aspect of the present invention is a process for debittering brewing yeast. Another aspect of the present invention is the use of a transition medium and a feed mediumto allow the biomass of a brewing yeast to be propagated and to obtain a debittered brewing yeast. Another aspect of the present invention is the use of a brewing yeast for the preparation of debittered yeast powder. Another aspect of the present invention is to provide a method for manufacturing a debittered yeast powder. Another aspect of the present invention is a debittered brewing yeast powder. Another aspect of the invention is the debittering of brewing yeasts without major chemical waste and in a minimal processing approach. Another aspect of the invention is the adjustment of the conditions of the propagation medium in order to maximize the degradation of bitter compounds, in particular via the oxidation of said bitter compounds. Disclosure of the invention The present invention relates to the use of a transition medium and a feed medium for implementing a method for debittering a yeastbrewing fermentation, in particular chosen from: Saccharomyces cerevisiae and Saccharomyces pastorianus, in which:□ said transition medium is an aqueous medium with a pH of from 3 to 10, in particular from 4 to 7, comprising:− from 0 to 50 g / L, in particular from 0 to 30 g / L, and more particularly from 0 to 10 g / L, of an ammonium salt chosen from: (NH4)2HPO4, (NH4)2SO4 and their mixture, or urea, protamylasse, corn solubles − from 0 to 10 g / L, in particular from 0 to 5 g / L, of a potassium salt chosen from: KH2PO4, K2HPO4 and their mixture,− from 0 to 5 g / L, in particular from 0 to 2 g / L, and more particularly from 0 to 1 g / L, of a magnesium salt, in particular MgSO4,− from 0 to 30 g glucose equivalent / L, in particular from 0 to 5 g glucose equivalent / L, of a carbon source chosen from: glucose, sucrose, maltose, maltotriose, fructose, mannose, galactose, raffinose, trehalose, glycerol, beet molasses, residues ofonion culture, beer production waste consisting of or comprising the supernatant from the sedimentation of fermented and drawn-off brewing yeast, brewer's grains, potato residue, bread production waste, dates, cane molasses, milling by-products, agri-food industry by-products, and mixtures thereof, said carbon source optionally being enzymatically treated, in particular by an α-amylase or an amyloglucosidase, and −from 0 to 15 g / L, in particular from 0 to 1 g / L, of inactivated microorganism extract;□ said feed medium is an aqueous medium with a pH of from 3 to 10, in particular from 4 to 7, comprising:− from 0 to 50 g / L, in particular from 0 to 30 g / L, and more particularly from 0 to 10 g / L, of an ammonium salt chosen from: (NH4)2HPO4, (NH4)2SO4 and their mixture, or urea, protamylasse, corn solubles, −from 0 to 10 g / L, in particular from 0 to 5 g / L, of a potassium salt chosen from:KH2PO4, K2HPO4 and their mixture,− from 0 to 5 g / L, in particular from 0 to 2 g / L, and more particularly from 0 to 1 g / L, of a magnesium salt, in particular MgSO4,− from 50 to 500 gglucose equivalent / L, in particular from 150 to 250 gglucose equivalent / L (preferably from 175 to 225 gglucose equivalent / L), of a carbon source chosen from: glucose, sucrose, maltose, maltotriose, fructose, mannose, galactose, raffinose, trehalose, glycerol, beet molasses, onion crop residues, beer production waste consisting of or comprising the supernatant from the sedimentation of a fermented and drawn-off brewing yeast, brewer's grain brewery, potato residue, bread production waste, dates, cane molasses, milling by-products, food industry by-products, and mixtures thereof, ethanol, preferably glucose, sucrose, maltose, maltotriose, ethanol,beet molasses, bread production waste, potato residue or beer production waste consisting of or comprising the supernatant resulting from the sedimentation of a fermented and drawn-off brewing yeast, and mixtures thereof, said carbon source being optionally enzymatically treated, in particular by an α-amylase or an amyloglucosidase, and −from 0 to 15 g / L, in particular from 0 to 1 g / L, of inactivated microorganism extract; and wherein said transition medium is used upstream of said feed medium, said feed medium supplementing said transition medium, said debittering of said yeast being:▪ a reduction of at least 70% in the alpha acid content, said alpha acids being in particular cohumulone, adhumulone and humulone; and / or, ▪a reduction of at least 50% in the alpha acid content beta, said beta acids being in particular lupulone, adlupulone and colupulone, said reductions being measuredcompared to said brewing yeast resulting from brewing fermentation. The inventors surprisingly discovered that the use of a transition medium and a feed medium made it possible to guarantee a low quantity of carbon source in the bioreactor, and thus to limit the alcoholic fermentation process in order to maintain the ethanol resulting from the fermentation at a rate below 20g / L, because an ethanol concentration above 20g / L slows down the propagation of the biomass and therefore the debittering process. By "brewing yeast" is meant a unicellular fungus capable of the alcoholic fermentation of sugary solutions. By way of non-limiting example, this yeast may be Saccharomyces cerevisiae or Saccharomyces pastorianus. By "resulting from brewing fermentation" is meant that the yeast is derived from the fermentation of beer. The brewing yeast resulting from brewing fermentation is recovered, possibly bycentrifugation and filtration of brewery tank bottoms. It separates the tank bottoms into three different fractions: Brewing residues (solid particles of hops, barley malt) Brewing yeasts A residue of wort during fermentation / beer The filtration step is optional when the brewing residue content is less than 40% of the dry matter of the tank bottoms in which fermentation took place. One aspect of the invention consists of culturing a brewing yeast resulting from brewing fermentation in a transition medium, to which a feed medium is gradually added, and whose increase in brewing yeast biomass makes it possible to drastically reduce the content of bitter molecules proportionally. The reduction in the content of bitter molecules also results from the oxidation of bitter molecules, which results in a degradation of the structure of alpha and / or alpha acidsbeta (i.e. change in their chemical configuration, such as the oxidation of an alcohol function into a ketone), to give rise to new molecules (for example humulinone or hulupone). The reduction in bitterness is due to the fact that some of these new molecules obtained after oxidation are less bitter than the bitter molecules initially present in the brewing yeast resulting from brewing fermentation. The invention involves a transition medium and a feeding medium. The "transition medium" designates a medium containing the microelements necessary to initiate the propagation of a microorganism, possibly a small quantity of carbon compounds as a source of carbon and energy and possibly an extract of inactivated microorganism. The pH value of this transition medium is from 3 to 10. This means: from 3 to 4, from 4 to 5, from 5 to 6, from 6 to 7, from 7 to 8, from 8 to 9, from 9 to 10. In a particular embodiment, the invention relates to the use of atransition medium and a feed medium for implementing a method for debittering a brewing yeast resulting from brewing fermentation as defined above, in which said transition medium is an aqueous medium with a pH of from 4 to 7, advantageously around 5. The pH in this particular embodiment is acidic. The debittering in this embodiment cannot be a chemical debittering in a basic medium. By "ammonium salt" is meant u+n ionic compound of cations and anions, in which at least one cation is an NH4 cation. This is present in an amount of "from 0 to 50 g / L". We understand: from 0 to 5 g / L, from 5 to 10 g / L, from 10 to 15 g / L, from 15 to 20 g / L, from 20 to 25 g / L, from 25 to 30 g / L, from 30 to 35 g / L, from 35 to 40 g / L, from 40 to 45 g / L, from 45 to 50 g / L. The expression "potassium salt" designates an ionic compound of cations and anions, in which at least one cation is a K+ cation. This is present at a rate of "from 0 to 10 g / L", we mean: from 0 to 1 g / L, from 1 to 2 g / L, from 2 to 3 g / L, from 3 to 4 g / L, from 4 to 5 g / L, from 5 to 6 g / L, from 6 to 7 g / L, from 7 to 8 g / L, from 8 to 9 g / L, from 9 to 10 g / L. The expression "magnesium salt" designates 2e+ an ionic compound of cations and anions, in which at least one cation is an Mg cation. This is present in an amount of "0 to 5 g / L", meaning: 0 to 0.5 g / L, 0.5 to 1 g / L, 1 to 1.5 g / L, 1.5 to 2 g / L, 2 to 2.5 g / L, 2.5 to 3 g / L, 3 to 3.5 g / L, 3.5 to 4 g / L, 4 to 4.5 g / L, 4.5 to 5 g / L. By "carbon source", we mean a product that can be assimilated by brewing yeast as a carbon compound that is a source of carbon and energy. The carbon source of the transition medium is chosen from: glucose, sucrose, maltose, maltotriose, fructose, mannose, galactose, raffinose, trehalose, glycerol, beet molasses, onion crop residues hydrolyzed by an α-amylase, beer production waste consisting of or comprising the supernatant resulting from the sedimentation of a fermented and drawn-off brewing yeast, brewing spent grain, potato residue hydrolyzed by an α-amylase,production gaps of bread, dates, cane molasses, milling by-products, food industry by-products, and their mixtures. This is present at a rate of "0 to 30 g / L" in the transition medium, we mean: 0 to 3 g / L, 3 to 6 g / L, 6 to 9 g / L, 9 to 12 g / L, 12 to 15 g / L, 15 to 18 g / L, 18 to 21 g / L, 21 to 24 g / L, 24 to 27 g / L, 27 to 30 g / L. The "supernatant resulting from the sedimentation of a fermented and drawn-off brewing yeast" corresponding to the supernatant liquid phase obtained at the end of the drawing-off of a brewing yeast during primary or secondary fermentation and its sedimentation. By "inactivated microorganism extract", we mean an extract of lysed microorganism which contributes to the propagation of the biomass by providing nutrients to brewing yeast, and which does not propagate alone. This is present at a rate of "0 to 15 g / L", we mean: 0 to 3 g / L, 3 to 6 g / L, 6 to 9 g / L,from 9 to 12 g / L and from 12 to 15 g / L. "Feeding medium" means a medium containing the microelements necessary for the propagation of a microorganism, a quantity of carbon compounds that are a source of carbon and energy higher than that of the transition medium and possibly an extract of inactivated microorganism. Salts and extracts of inactivated microorganism in the feeding medium meet the same definitions as in the transition medium. The pH value of this feeding medium is from 3 to 10. This means: from 3 to 4, from 4 to 5, from 5 to 6, from 6 to 7, from 7 to 8, from 8 to 9, from 9 to 10. The carbon source of the feeding medium is chosen from: glucose, sucrose, maltose, maltotriose, fructose, mannose, galactose, raffinose, trehalose, glycerol, beet molasses, onion crop residues hydrolyzed by an α-amylase,beer production deviations consisting of or comprising the supernatant resulting from the sedimentation of a fermented and drawn-off brewing yeast, brewer's grains, potato residue hydrolyzed by an α-amylase, bread production deviations, dates, cane molasses, milling by-products, food industry by-products, and mixtures thereof, preferably glucose, sucrose, maltose, maltotriose, ethanol, beet molasses, bread production deviations, potato residue or beer production deviations consisting of or comprising the supernatant resulting from the sedimentation of a fermented and drawn-off brewing yeast, and mixtures thereof. This is present at a rate of "50 to 500 g / L" in the feed medium, we mean: 50 to 100 g / L 100 to 150 g / L, 150 to 200 g / L, 200 to 250 g / L, 250 to 300 g / L, 300 to 350 g / L, 350 to 400 g / L, 400 to 450 g / L,from 450 to 500 g / L. The propagation of the biomass occurs in the medium formed by the transition medium to which the feed medium is gradually added. If ethanol is chosen as the carbon source, and it is present at a rate greater than 20 g / L in the transition medium to which the feed medium is gradually added, then the propagation of the biomass is slowed down compared to another carbon source. Preferably, the ethanol content is not greater than 20 g / L in the total volume formed by the transition medium, and the feed medium added to the bioreactor. The expression "gglucose equivalent / L" designates the quantity of glucose that would be necessary to produce the same quantity of biomass by the debittering process as the carbon source considered here and which is not glucose. This unit concerns both the transition medium and the feed medium. By "debittering",The term "bitter molecule" refers to the reduction of the content of bitter molecules below the threshold of perception by a human being so that the yeasts can be used for the manufacture of food products. Bitter molecules can be of natural or synthetic origin and are perceived by taste receptors in the taste buds of the tongue and soft palate by taste receptors (type 2 receptors or T2R). The invention makes it possible to reduce the content of bitter molecules of, in particular, cohumolone, humolone, adhumolone, colupulone, lupulone, adlupulone, isocohumolone, isohumulone, isoadhumulone, xanthohumol, hulupone, humulinone, and humulinic acid. The bitter molecules adsorbed on the walls of brewing yeasts are derived from lupulin and are: ●Alpha acids, with the following structures:, ●Beta acids, with the following structures: adlupulone The possible enzymatic pretreatment of the carbon source is a pre-treatment using one or more enzymes, in order to generate a product that can be assimilated by brewing yeast. The nitrogen source may be a co-product or by-product of the food industry. The term “corn soluble” refers to corn steeping water, concentrated or not, produced during the starch process. The term “protamylasse” refers to a concentrate obtained by evaporation of potato vegetation water during the starch process. In particular, the carbon source may be a co-product or by-product of the food industry. The term “beet molasses” refers to a non-crystallizable syrupy liquid,residue from the crystallization and refining of beet sugar. The term "onion crop residue" refers to peelings or any other unused part of the onion. The term "beer production variance" refers to all fractions of brewery production that are not packaged or marketed. "Brewer's spent grain" refers to the cooked barley residue that remains in the vat after mashing and before boiling the wort. The term "potato residue" refers to peelings, any other unused part of the potato or downgraded whole potatoes. The term "bread production variance" refers to non-compliant kneading machines and finished products obtained during bakery production. The term "date" here refers to a fruit of Phoenix dactylifera. The term "cane molasses" refers to a non-crystallizable syrupy liquid,residue from the crystallization and refining of sugar from sugar cane. The expression "brans and sharps" refers to co-products of semolina or milling which may be derived from durum wheat, soft wheat, corn or spelt. The expression "co-products of the agri-food industry" here refers to an intentional and unavoidable material created during the same manufacturing process and at the same time as the main product obtained in the context of an agri-food manufacturing process. The expression "internal wash water" refers to the wash water produced during the production of debittered brewer's yeast. The expression "wash water from the agri-food industries" refers to the wash water from other agri-food productions. In a particular embodiment,the invention relates to the use of a transition medium and a feed medium for implementing a method for debittering a brewing yeast resulting from brewing fermentation as defined above, in which said carbon source of the transition medium is identical to said carbon source of the feed medium. In this embodiment, the use of an identical carbon source between the transition medium and the feed medium involves an optimized time, in the absence of the latency time linked to the change of carbon source. In a particular embodiment, the invention relates to the use of a transition medium and a feed medium for implementing a method for debittering a brewing yeast resulting from brewing fermentation as defined above,wherein said carbon source of the transition medium is different from said carbon source of the feed medium. In a particular embodiment, the invention relates to the use of a transition medium and a feed medium for implementing a method for debittering a brewing yeast resulting from brewing fermentation as defined above, further enabling a reduction of at least 60% in the purine content, said purines being in particular adenine, guanine, adenosine, hypoxanthine, guanosine and xanthine. The expression "purines" designates aromatic heterocycles composed of carbon and nitrogen. Purines include adenine and guanine, which participate in the formation of DNA and RNA. The invention makes it possible to reduce the content of other bitter molecules, in particular iso-alpha acids, in particular, isocohumolone, isohumulone, isoadhumulone, xanthohumol, hulupone, humulinone,and humulinic acid. In a particular embodiment, the invention relates to the use of a transition medium and a feed medium for implementing a process for debittering a brewing yeast resulting from brewing fermentation as defined above, allowing a reduction of at least 60% in the content of iso-alpha acids, said iso-alpha acids being in particular isocohumolone, isohumolone and isoadhumulone. Another aspect of the invention relates to the use of a transition medium and a feed medium for the preparation of a debittered yeast powder from a brewing yeast resulting from brewing fermentation, in particular chosen from: Saccharomycescerevisiae and Saccharomyces pastorianus, in which:□ said transition medium is an aqueous medium with a pH of from 3 to 10, in particular from 4 to 7 (and more particularly from 5), comprising:− from 0 to 50 g / L, in particular from 0 to 30 g / L,and more particularly from 0 to 10 g / L, of an ammonium salt chosen from: (NH4)2HPO4, (NH4)2SO4 and their mixture, or urea, protamylasse, corn solubles −from 0 to 10 g / L, in particular from 0 to 5 g / L, of a potassium salt chosen from: KH2PO4, K2HPO4 and their mixture,− from 0 to 5 g / L, in particular from 0 to 2 g / L, and more particularly from 0 to 1 g / L, of a magnesium salt, in particular MgSO4,− from 0 to 30 gglucose equivalent / L, in particular from 0 to 5 gglucose equivalent / L, of a carbon source chosen from: glucose, sucrose, maltose, maltotriose, fructose, mannose, galactose, raffinose, trehalose, glycerol, beet molasses, onion crop residues, beer production waste consisting of or comprising the supernatant from the sedimentation of fermented and drawn-off brewing yeast, brewer's grains, potato residue, bread production waste, dates, cane molasses,by-products of milling, by-products of the agri-food industry, and mixtures thereof, said carbon source being optionally treated enzymatically, in particular by an α-amylase or an amyloglucosidase, and −from 0 to 15 g / L, in particular from 0 to 1 g / L, of inactivated microorganism extract;□ said feeding medium is an aqueous medium with a pH of from 3 to 10, in particular from 4 to 7 (and more particularly from 5 to 6), comprising:− from 0 to 50 g / L, from 0 to 30 g / L, and more particularly from 0 to 10 g / L, of an ammonium salt chosen from: (NH4)2HPO4, (NH4)2SO4 and their mixture, or urea, protamylasse, corn solubles, −from 0 to 10 g / L, in particular from 0 to 5 g / L, of a potassium salt chosen from: KH2PO4, K2HPO4 and their mixture,− from 0 to 5 g / L, from 0 to 2 g / L, and more particularly from 0 to 1 g / L, of a magnesium salt, in particular MgSO4,− from 50 to 500 gglucose equivalent / L, in glucose equivalent, l p u c a o sr e tic e q u u l i v ie has le r from 150 to 250 g / L, preferably from 175 to 225 g nt / L, of a carbon source chosen from: glucose, sucrose, maltose, maltotriose, fructose, mannose, galactose, raffinose, trehalose, glycerol, beet molasses, onion crop residues, beer production deviations consisting of or comprising the supernatant from the sedimentation of a fermented and drawn-off brewing yeast, brewery spent grain, potato residue, bread production deviations, dates, cane molasses, milling by-products, food industry by-products, ethanol and mixtures thereof, preferably glucose, sucrose, maltose, maltotriose, ethanol, beet molasses, bread production deviations, potato residue or beer production deviations consisting of of or comprising the supernatant resulting from the sedimentation of a fermented and drawn-off brewing yeast,and mixtures thereof, said carbon source being optionally treated enzymatically, in particular by an α-amylase or an amyloglucosidase, and −from 0 to 15 g / L, in particular from 0 to 1 g / L, of inactivated microorganism extract;said debittered yeast powder comprising:▪ from 0.002 to 0.400 mg of alpha acids / g of debittered yeasts, preferably from 0.050 to 0.200 mg of alpha acids / g of debittered yeasts, said alpha acids being in particular cohumulone, adhumulone and humulone; and / or, ▪from 0.001 to 0.300 mg of beta acids / g of debittered yeasts, preferably from 0.001 to 0.010 mg of beta acids / g of yeasts debittered, said beta acids being in particular lupulone, adlupulone and colupulone, and said debittered yeast powder having a bitterness equal to the bitterness of 0.060 to 0.250 mg of isohumulones / g of dry yeast, in particular equal to 0.125 mg of isohumulones / g of dry yeast.In a particular embodiment,the invention relates to the use of a transition medium and a feed medium for the preparation of a debittered yeast powder from a brewing yeast resulting from brewing fermentation, in particular chosen from: Saccharomyces cerevisiae and Saccharomyces pastorianus, in which:□ said transition medium is an aqueous medium with a pH of from 3 to 10, in particular from 4 to 7 (and more particularly from 5), comprising:− from 0 to 50 g / L, in particular from 0 to 30 g / L, and more particularly from 0 to 10 g / L, of an ammonium salt chosen from: (NH4)2HPO4, (NH4)2SO4 and their mixture, or urea, protamylasse, corn solubles − from 0 to 10 g / L, in particular from 0 to 5 g / L, of a potassium salt chosen from: KH2PO4, K2HPO4 and their mixture,− from 0 to 5 g / L, in particular from 0 to 2 g / L, and more particularly from 0 to 1 g / L, of a magnesium salt, in particular MgSO4, − from 0 to 30 gglucose equivalent / L, in particular from 0 to 5 gglucose equivalent / L,of a carbon source chosen from: glucose, sucrose, maltose, maltotriose, fructose, mannose, galactose, raffinose, trehalose, glycerol, beet molasses, onion crop residues, beer production waste consisting of or comprising the supernatant resulting from the sedimentation of a fermented and drawn-off brewing yeast, brewer's grains, potato residue, bread production waste, dates, cane molasses, milling by-products, food industry by-products, and mixtures thereof, said carbon source being optionally enzymatically treated, in particular by an α-amylase or an amyloglucosidase, and −from 0 to 15 g / L, in particular from 0 to 1 g / L, of extract of inactivated microorganism;□ said feeding medium is an aqueous medium with a pH of from 3 to 10, in particular from 4 to 7 (and more particularly from 5 to 6), comprising:− from 0 to 50 g / L, from 0 to 30 g / L,and more particularly from 0 to 10 g / L, of an ammonium salt chosen from: (NH4)2HPO4, (NH4)2SO4 and their mixture, or urea, protamylasse, corn solubles, − from 0 to 10 g / L, in particular from 0 to 5 g / L, of a potassium salt chosen from: KH2PO4, K2HPO4 and their mixture, − from 0 to 5 g / L, from 0 to 2 g / L, and more particularly from 0 to 1 g / L, of a magnesium salt, in particular MgSO4, − from 50 to 500 gglucose equivalent / L, in glucose equivalent, l p u c a o s r e tic e q u u l i v ie has le r from 150 to 250 g / L, preferably from 175 to 225 g nt / L, of a carbon source chosen from: glucose, sucrose, maltose, maltotriose, fructose, mannose, galactose, raffinose, trehalose, glycerol, beet molasses, onion crop residues, beer production deviations consisting of or comprising the supernatant from the sedimentation of a fermented and drawn-off brewing yeast, brewery spent grain, potato residue, bread production deviations, dates, cane molasses, milling by-products, food industry by-products, ethanol and mixtures thereof, preferably glucose, sucrose, maltose, maltotriose, ethanol, beet molasses, bread production deviations, potato residue or beer production deviations consisting of of or comprising the supernatant resulting from the sedimentation of a fermented and drawn-off brewing yeast,and mixtures thereof, said carbon source being optionally treated enzymatically, in particular by an α-amylase or an amyloglucosidase, and −from 0 to 15 g / L, in particular from 0 to 1 g / L, of inactivated microorganism extract;said debittered yeast powder comprising:▪ from 0.002 to 0.400 mg of alpha acids / g of debittered yeasts, preferably from 0.050 to 0.200 mg of alpha acids / g of debittered yeasts, said alpha acids being in particular cohumulone, adhumulone and humulone; and / or, ▪from 0.001 to 0.300 mg of beta acids / g of debittered yeasts, preferably from 0.001 to 0.010 mg of beta acids / g of yeasts debittered, said beta acids being in particular lupulone, adlupulone and colupulone, and said debittered yeast powder has a bitterness equal to the bitterness of 0 to 0.12 mg of isohumulones / g of dry yeast, in particular of 0 to 0.06 mg of isohumulones / g of dry yeast, in particular,said transition medium comprising a carbon source selected from: beer production waste consisting of or comprising the supernatant from the sedimentation of a fermented and drawn-off brewing yeast, potato residue, glucose, sucrose, maltose, maltotriose, beet molasses, bread production waste and mixtures thereof, preferably beer production waste consisting of or comprising the supernatant from the sedimentation of a fermented and drawn-off brewing yeast, said carbon source optionally being enzymatically treated. The expression "debittered yeast powder" designates a solid composition formed from yeasts that have been subjected to the debittering process. It is the yeasts that are debittered. By "dry yeast" is meant a yeast having a water content of at least 0% and at most 10%,the percentage being expressed in mass relative to the total mass of the yeast. By range of "0.002 to 0.400 mg of alpha acids / g of debittered yeasts" is meant: from 0.002 to 0.010, from 0.010 to 0.020, from 0.020 to 0.030, from 0.030 to 0.040, from 0.040 to 0.050, from 0.050 to 0.060, from 0.060 to 0.070, from 0.070 to 0.080, from 0.080 to 0.090, from 0.090 to 0.100, from 0.100 to 0.110, from 0.110 to 0.120, from 0.120 to 0.130, from 0.130 to 0.140, from 0.140 to 0.150, from 0.150 to 0.160, from 0.160 to 0.170, from 0.170 to 0.180, from 0.180 to 0.190, from 0.190 to 0.200, from 0.200 to 0.210, from 0.210 to 0.220, from 0.220 to 0.230, from 0.230 to 0.240, from 0.240 to 0.250, from 0.250 to 0.260, from 0.260 to 0.270, from 0.270 to 0.280, from 0.280 to 0.290, from 0.290 to 0.300, from 0.300 to 0.310, from 0.310 to 0.320, from 0.030 to 0.330, from 0.330 to 0.340, from 0.340 to 0.350, from 0.350 to 0.360, from 0.360 to 0.370, from 0.370 to 0.380, from 0.380 to 0.390 and from 0.390 to 0,400. These value ranges also apply to the yeast powder according to the invention and to the method for manufacturing a yeast powder according to the invention. By range of "0.001 to 0.300 mg of beta acids / g of debittered yeasts" is meant: from 0.001 to 0.010, from 0.010 to 0.020, from 0.020 to 0.030, from 0.030 to 0.040, from 0.040 to 0.050, from 0.050 to 0.060, from 0.060 to 0.070, from 0.070 to 0.080, from 0.070 to 0.080, from 0.080 to 0.090, from 0.090 to 0.100, from 0.100 to 0.110, from 0.110 to 0.120, from 0.120 to 0.130, from 0.130 to 0.140, from 0.140 to 0.150, from 0.150 to 0.160, from 0.160 to 0.170, from 0.170 to 0.180, from 0.180 to 0.190, from 0.190 to 0.200, from 0.210 to 0.220, from 0.220 to 0.230, from 0.230 to 0.240, from 0.240 to 0.250, from 0.250 to 0.260, from 0.260 to 0.270, from 0.270 to 0.280, from 0.280 to 0.290, and from 0.290 to 0.300. These ranges of values ​​also apply to the yeast powder according to the invention and to the process for manufacturing a yeast powder according to the invention. Beyond a bitterness value greater than 0,250 mg of isohumulones / g of dry yeast, yeasts are not usable as an ingredient in the food industry without the introduction of bitter taste to the final product. By range of "from 0 to 0.12 mg of isohumulones / g of dry yeast" we mean: from 0 to 0.01, from 0.01 to 0.02, from 0.02 to 0.03, from 0.03 to 0.04, from 0.04 to 0.05, from 0.05 to 0.06, from 0.06 to 0.07, from 0.07 to 0.08, from 0.08 to 0.09, from 0.09 to 0.10, from 0.10 to 0.11 and from 0.11 to 0.12. These ranges of values ​​also apply for the yeast powder according to the invention and for the method of manufacturing a yeast powder according to the invention. The use of a transition medium and a feed medium for implementing a method of debittering a brewing yeast resulting from the brewing fermentation according to the invention may involve an enzymatic treatment of the carbon source of the transition medium and / or the feed medium. In a particular embodiment,The invention relates to the use of a transition medium and a feed medium for the preparation of a debittered yeast powder from a brewing yeast resulting from brewing fermentation as defined above, said debittered yeast powder further comprising from 3 to 8 mg of purines / g of debittered yeast, in particular 5 mg of purines / g of debittered yeast, said purines being in particular adenine, guanine, adenosine, hypoxanthine, guanosine and xanthine. In a particular embodiment, the invention relates to the use as defined above, in which said transition medium comprises a carbon source chosen from: beer production waste consisting of or comprising the supernatant resulting from the sedimentation of a fermented and drawn-off brewing yeast, potato residue, glucose, sucrose, maltose, maltotriose, beet molasses,bread production deviations and mixtures thereof, preferably beer production deviations consisting of or comprising the supernatant resulting from the sedimentation of a fermented and drawn-off brewing yeast, said carbon source being optionally enzymatically treated. In the transition medium, the carbon source may or may not be enzymatically treated. The carbon source is not enzymatically treated when the carbon source is directly assimilable by the yeast. By way of example and in a non-limiting manner, when the carbon source of the transition medium is glucose, glycerol, sucrose, maltose, maltotriose, fructose, mannose, galactose, raffinose, trehalose, beet molasses, cane molasses, onion crop residues, dates, brewer's spent grain, beer production deviations,certain agri-food co-products or the carbon source is not enzymatically treated. The enzymatic treatment of the carbon source makes it possible to make the carbon source assimilable by the yeast, and occurs when the carbon source is not directly assimilable by the yeast. By way of example and in a non-limiting manner, when the carbon source of the transition medium is potato residues, brewer's grains, beer production waste or bread production waste, milling co-products then the carbon source is enzymatically treated by at least one of the following enzymes: α-amylase, protease, cellulase, β-glucanase and amyloglucosidase. In a particular embodiment,the invention relates to the use of a transition medium and a feed medium for implementing a process for debittering a brewing yeast resulting from brewing fermentation as defined above, said process not involving an enzyme in carrying out the debittering. The present invention may involve a treatment of the carbon source to make the carbon source assimilable by the yeast, but this enzymatic treatment is not involved in carrying out the debittering. In a particular embodiment, the invention relates to the use as defined above of a transition medium and a feed medium for preparing a debittered yeast powder from a brewing yeast resulting from brewing fermentation, in particular chosen from: Saccharomyces cerevisiae and Saccharomyces pastorianus,in which:□ said transition medium is an aqueous medium with a pH of from 3 to 10, in particular from 4 to 7 (and more particularly 5), comprising:− from 0 to 50 g / L, from 0 to 30 g / L, and more particularly from 0 to 10 g / L, of an ammonium salt chosen from: (NH4)2HPO4, (NH4)2SO4 and their mixture, or urea, corn solubles, protamylasse, − from 0 to 10 g / L, in particular from 0 to 5 g / L, of a potassium salt chosen from: KH2PO4, K2HPO4 and their mixture,− from 0 to 5 g / L, from 0 to 2 g / L, and more particularly from 0 to 1 g / L, of a magnesium salt, in particular MgSO4,− from 0 to 30 gglucose equivalent / L, in particular from 0 to 5 gglucose equivalent / L, of a carbon source chosen from: glucose, sucrose, maltose, maltotriose, fructose, mannose, galactose, raffinose, trehalose, glycerol, beet molasses, onion crop residues,beer production waste consisting of or comprising the supernatant from the sedimentation of fermented and drawn-off brewing yeast, brewery spent grain, potato residue, bread production waste, dates, cane molasses, milling by-products, food industry by-products, and mixtures thereof, said carbon source optionally being enzymatically treated, in particular by an α-amylase or an amyloglucosidase or a protease, and− from 0 to 15 g / L, in particular from 0 to 1 g / L, of inactivated microorganism extract;□ said feed medium is an aqueous medium with a pH of from 3 to 10, in particular from 4 to 7 (and more particularly from 5 to 6), comprising:− from 0 to 50 g / L, in particular from 0 to 30 g / L, and more particularly from 0 to 10 g / L, of an ammonium salt chosen from: (NH4)2HPO4, (NH4)2SO4 and their mixture, or urea, corn solubles, protamylasse, −from 0 to 10 g / L, in particular from 0 to 5 g / L,of a potassium salt chosen from: KH2PO4, K2HPO4 and their mixture,− from 0 to 5 g / L, from 0 to 2 g / L, and more particularly from 0 to 1 g / L, of a magnesium salt, in particular MgSO4,− from 50 to 500 g glucose equivalent / L, in particular from 150 to 250 g glucose equivalent, preferably from 175 to 225 g, glucose / L,equivalent / L, of a carbon source chosen from: glucose, sucrose, maltose, maltotriose, fructose, mannose, galactose, raffinose, trehalose, glycerol, beet molasses, onion crop residues, beer production deviations consisting of or comprising the supernatant resulting from the sedimentation of a fermented and drawn-off brewing yeast, brewery spent grain, potato residue, bread production deviations, dates, cane molasses, milling by-products, food industry by-products, ethanol and mixtures thereof, preferably glucose, sucrose, maltose, maltotriose, ethanol, beet molasses, bread production deviations, potato residue or beer production deviations consisting of or comprising the supernatant resulting from the sedimentation of a fermented and drawn-off brewing yeast,and mixtures thereof, said carbon source being optionally treated enzymatically, in particular by an α-amylase, an amyloglucosidase or a protease, and −from 0 to 15 g / L, in particular from 0 to 1 g / L, of inactivated microorganism extract;said debittered yeast powder comprising:▪ from 0.002 to 0.400 mg of alpha acids / g of debittered yeast, preferably from 0.050 to 0.200 mg of alpha acids / g of debittered yeast, said alpha acids being in particular cohumulone, adhumulone and humulone; and / or, ▪from 0.001 to 0.300 mg of beta acids / g of debittered yeast, preferably from 0.001 to 0.010 mg of beta acids / g of debittered yeasts, said beta acids being in particular lupulone, adlupulone and colupulone. and said debittered yeast powder having a bitterness equal to the bitterness of 0.060 to 0.250 mg of isohumulones / g of dry yeasts, in particular equal to 0.125 mg of isohumulones / g of dry yeast, in particular,said transition medium comprising a carbon source selected from: beer production gaps consisting of or comprising the supernatant from the sedimentation of a fermented and drawn-off brewing yeast, potato residue, glucose, sucrose, maltose, maltotriose, beet molasses, bread production gaps and mixtures thereof, preferably beer production gaps consisting of or comprising the supernatant from the sedimentation of a fermented and drawn-off brewing yeast, said carbon source optionally being enzymatically treated.In a particular embodiment, the invention relates to the use of a transition medium and a feed medium for the preparation of a debittered yeast powder from a brewing yeast resulting from the brewing fermentation as defined above, wherein said debittered yeast powder has a bitterness equal to the bitterness of 0 to 0,12 mg of isohumulones / g of dry yeast, in particular from 0 to 0.06 mg of isohumulones / g of dry yeast. In a particular embodiment, the invention relates to the use as defined above, in which said transition medium comprises a carbon source chosen from: beer production gaps consisting of or comprising the supernatant resulting from the sedimentation of a fermented and drawn-off brewing yeast, potato residue, glucose, sucrose, maltose, maltotriose, beet molasses, bread production gaps and mixtures thereof, preferably beer production gaps consisting of or comprising the supernatant resulting from the sedimentation of a fermented and drawn-off brewing yeast, said carbon source being treated enzymatically, in particular by an α-amylase,an amyloglucosidase or protease. The role of α-amylase is to break the α(1→4)glycosidic bonds within the amylose and amylopectin chains to yield maltose molecules. The role of amyloglucosidase is to catalyze the hydrolysis of unsubstituted glucose units in starch linked by α(1→6) bonds to the α(1→4)glucose chains and to generate glucose as a carbon source. The role of the protease is to hydrolyze the peptide bonds between the amino acids of gluten proteins, and to release peptides and amino acids as a source of nitrogen.In a particular embodiment, the invention relates to the use as defined above, in which said transition medium comprises a carbon source chosen from: beer production waste consisting of or comprising the supernatant from the sedimentation of a fermented and drawn-off brewing yeast, potato residue, glucose, sucrose,maltose, maltotriose, beet molasses, bread production waste and mixtures thereof, preferably beer production waste consisting of or comprising the supernatant from the sedimentation of a fermented and drawn-off brewing yeast, said carbon source being enzymatically treated, in particular by an α-amylase, an amyloglucosidase or a protease.In a particular embodiment the invention relates to the use as defined above, wherein said transition medium comprises a carbon source consisting of bread production waste, said carbon source, which carbon source is optionally enzymatically treated by an α-amylase and an amyloglucosidase and either a protease or an acid protease. In a particular embodiment the invention relates to the use as defined above,wherein said transition medium comprises a carbon source selected from: beer production gaps consisting of or comprising the supernatant from the sedimentation of a fermented and drawn-off brewing yeast, potato residue, glucose, sucrose, maltose, maltotriose, beet molasses, bread production gaps and mixtures thereof, preferably beer production gaps consisting of or comprising the supernatant from the sedimentation of a fermented and drawn-off brewing yeast, said carbon source not being enzymatically treated. In a particular embodiment, the invention relates to the use as defined above, in which said transition medium further comprises:▪ mineral salts chosen from: ZnSO4 at a rate of 0 to 20 mg / L, in particular 3 to 10 mg / L, CaCl2 at a rate of 0 to 1 g / L, in particular 50 to 200 mg / L, FeSO4 at a rate of 0 to 20 mg / L, in particular 3 to 10 mg / L,H3BO3, CuSO4, Na2MoO4, MnCl2, CoCl2, KCI and mixtures thereof; and / or▪ EDTA; and / or▪ vitamins chosen from: vitamin B1 (thiamine) at a rate of 0 to 20mg / L, in particular 6 to 10mg / L, vitamin B2 (riboflavin) at a rate of 0 to 20mg / L, in particular 1 to 5mg / L, vitamin B3 (niacin) at a rate of 0 to 10mg / L, in particular 0 to 3mg / L, vitamin B5 (calcium pantothenate) at a rate of 0 to 20mg / L, in particular 2 to 6mg / L, vitamin B6 (pyridoxine) at a rate of 0 to 20mg / L, in particular 2 to 6mg / L), vitamin B7 (inositol) at a rate of 0 to 20mg / L, in particular 8 to 15mg / L), vitamin B8 (biotin) at a rate of 0 to 2mg / L, vitamin B10 (acid para-aminobenzoic acid) at a rate of 0 to 2 mg / L and mixtures thereof; and / or▪ peptone at a rate of 0 to 20 g / L; and / or▪ Yeast Nitrogen Base (YNB),▪ surfactants at a rate of 0 g / L to 1 g / L.In a particular embodiment, the invention relates to the use as defined above,wherein said transition medium does not comprise a surfactant. In a particular embodiment, the invention relates to the use as defined above, wherein said transition medium further comprises surfactants in an amount of less than 1 g / L. The microelements necessary for the propagation of a microorganism are, for example and in a non-limiting manner: ammonium salts, potassium salts, magnesium salts, zinc salts, calcium salts, iron salts, boron salts, copper salts, molybdenum salts, manganese salts, cobalt salts, potassium salts, urea, EDTA, thiamine, riboflavin, niacin, calcium pantothenate, pyridoxine, inositol, biotin,para-aminobenzoic acid, peptone and Yeast Nitrogen Base. The term "surfactants" refers to compounds capable of modifying the surface tension between a lipophilic phase and a hydrophilic phase. By way of example and in a non-limiting manner, the surfactants may be a mixture of polyether polyols. In a particular embodiment, the invention relates to the use as defined above, wherein said feed medium comprises a carbon source chosen from: beer production waste consisting of or comprising the supernatant from the sedimentation of a fermented and drawn-off brewing yeast, potato residue, glucose, sucrose, maltose, maltotriose, ethanol, beet molasses, bread production waste and mixtures thereof,preferably beer production gaps consisting of or comprising the supernatant resulting from the sedimentation of a fermented and drawn-off brewing yeast, said carbon source optionally being enzymatically treated. In the feed medium, the carbon source may or may not be enzymatically treated. The carbon source is not enzymatically treated when the carbon source is directly assimilable by the yeast. The enzymatic treatment of the carbon source makes it possible to make the carbon source assimilable by the yeast, and occurs when the carbon source is not directly assimilable by the yeast.In a particular embodiment, the invention relates to the use as defined above, in which said feed medium comprises a carbon source chosen from: beer production gaps consisting of or comprising the supernatant resulting from the sedimentation of a fermented and drawn-off brewing yeast,potato residue, glucose, sucrose, maltose, maltotriose, ethanol, beet molasses, bread production waste and mixtures thereof, preferably beer production waste consisting of or comprising the supernatant from the sedimentation of a fermented and drawn-off brewing yeast, said carbon source being treated enzymatically, in particular by an α-amylase, an amyloglucosidase or a protease. In a particular embodiment, the invention relates to the use as defined above, wherein said feed medium comprises a carbon source chosen from: beer production waste consisting of or comprising the supernatant from the sedimentation of a fermented and drawn-off brewing yeast, potato residue, glucose, sucrose, maltose, maltotriose, ethanol, beet molasses, bread production waste and mixtures thereof,preferably beer production gaps consisting of or comprising the supernatant from the sedimentation of a fermented and drawn-off brewing yeast, said carbon source optionally being enzymatically treated, in particular by an α-amylase, an amyloglucosidase and a protease. In a particular embodiment, the invention relates to the use as defined above, wherein said feed medium comprises a carbon source selected from: beer production gaps consisting of or comprising the supernatant from the sedimentation of a fermented and drawn-off brewing yeast, potato residue, glucose, sucrose, maltose, maltotriose, ethanol, beet molasses, bread production gaps and mixtures thereof, preferably beer production gaps consisting of or comprising the supernatant from the sedimentation of a fermented and drawn-off brewing yeast,said carbon source not being enzymatically treated. In a particular embodiment, the invention relates to the use as defined above, wherein said feed medium further comprises:▪ mineral salts chosen from: ZnSO4, CaCl2, FeSO4, H3BO3, CuSO4, Na2MoO4, MnCl2, CoCl2, KCI and mixtures thereof; and / or▪ EDTA; and / or▪ vitamins chosen from: vitamin B1 (thiamine), vitamin B2 (riboflavin), vitamin B3, vitamin B5 (calcium pantothenate), vitamin B6, vitamin B7 (inositol), vitamin B8 (biotin), vitamin B10 and mixtures thereof; and / or▪ peptone; and / or▪ Yeast Nitrogen Base (YNB).In a particular embodiment, the invention relates to the use as defined above,wherein said feed medium comprises a carbon source selected from: beer production variances consisting of or comprising the supernatant from the sedimentation of a fermented and drawn-off brewing yeast, potato residue, glucose, sucrose, maltose, maltotriose, ethanol, beet molasses, bread production variances and mixtures thereof, preferably beer production variances consisting of or comprising the supernatant from the sedimentation of a fermented and drawn-off brewing yeast, said carbon source optionally being enzymatically treated. and optionally wherein said feed medium further comprises:▪ mineral salts selected from: ZnSO4, CaCl2, FeSO4, H3BO3, CuSO4, Na2MoO4, MnCl2, CoCl2, KCl and mixtures thereof; and / or▪ EDTA; and / or▪ vitamins chosen from: vitamin B1 (thiamine), vitamin B2 (riboflavin), vitamin B3,vitamin B5 (calcium pantothenate), vitamin B6, vitamin B7 (inositol), vitamin B8 (biotin), vitamin B10 and mixtures thereof; and / or▪ peptone; and / or▪ Yeast Nitrogen Base (YNB).Another subject of the invention relates to the use of a transition medium and a feed medium for carrying out a debittering process for preparing a debittered yeast powder from a brewing yeast resulting from brewing fermentation. The invention also relates to the debittered yeast powder obtainable by using the transition and feed media defined above. Another aspect of the invention also relates to the debittered yeast powder comprising:▪ from 0.002 to 0.400 mg of alpha acids / g of debittered yeast, preferably from 0.050 to 0.200 mg of alpha acids / g of debittered yeast, said alpha acids being in particular cohumulone, adhumulone and humulone;▪ from 0.001 to 0.300 mg of beta acids / g of debittered yeasts, preferably from 0.001 to 0.010 mg of beta acids / g of debittered yeasts, said beta acids being in particular lupulone, adlupulone and colupulone; said debittered yeast powder having a bitterness equal to the bitterness of 0.0625 to 0.250 mg of isohumulones / g of dry yeasts, in particular equal to 0.125 mg of isohumulones / g of dry yeast, said debittered yeast powder having a dry matter content of 90 to 100%, in particular 92 to 98%, and said debittered yeast powder being in particular in ground form, said ground debittered yeast powder having in particular a median particle size of 5 to 200 µm, in particular from 6 to 80 µm, in particular from 8 to 30 µm. In a particular embodiment, the invention relates to a debittered yeast powder as defined above, wherein said debittered yeast powder has a bitterness equal to the bitterness of 0 to 0,12 mg isohumulones / g dry yeast, in particular 0 to 0.06 mg isohumulones / g dry yeast. "Bitterness" means bitterness as one of the five primary tastes, namely: sweet, salty, bitter, sour and umami. "90 to 100%" means: 90% to 91%, 91% to 92%, 92 to 93%, 93 to 94%, 94% to 95%, 95% to 96%, 96 to 97%, 97 to 98%, 98% to 99%, 99 to 100%. The expression "median particle size" designates the size of the particles of the debittered yeast powder, for which 50% of the particles in number, mass or volume, have a smaller size. The method of measuring the median particle size does not influence the result obtained, and the median particle size can be measured using a device known to those skilled in the art, by way of example and in a non-limiting manner, using a Mastersizer 3000+ laser particle sizer. By "from 5 to 200 µm", we mean: from 5 to 15 µm, from 15 to 25 µm, from 25 to 35 µm, from 35 to 45 µm, from 45 to 55 µm,from 55 to 65 µm, from 65 to 75 µm, from 75 to 85 µm, from 85 to 95 µm, from 95 to 105 µm, from 105 to 115 µm, from 115 to 125 µm, from 125 to 135 µm, from 135 to 145 µm, from 145 to 155 µm, from 155 to 165 µm, from 165 to 175 µm, from 175 to 185 µm, from 185 to 195 µm and from 195 to 200 µm. In a particular embodiment, the invention relates to a debittered yeast powder as defined above, further comprising from 3 to 8 mg of purines / g of debittered yeast, in particular 5 mg of purines / g of debittered yeast, said purines being in particular adenine, guanine, adenosine, hypoxanthine, guanosine and xanthine, In a particular embodiment, the invention relates to a debittered yeast powder as defined above, said debittered yeast powder having a dispersibility of from 60 to 100%,in particular from 75 to 95%. The term "dispersibility" refers to the ability of the powder to disperse uniformly in water under stirring. Dispersion is evaluated according to the following protocol: A quantity of 2.5 g of the yeast powder was added to a 25 mL graduated cylinder. Distilled water was added up to the 25 mL graduation. The mixture was left to stand for 3 hours, then the sedimented volume was measured. The dispersibility value is calculated as: ((Volume1 - Volume2) / Volume1) * 100 with Volume1 being the initial volume in the cylinder (25 mL) and Volume2 being the sedimented volume after 3 hours. The method of measuring dispersibility does not influence the result obtained, and the dispersibility capacity can be measured using a method known to those skilled in the art (For example, see G. Methods of Testing Protein Functionality,Food / Nahrung.1997;41(1):55-55)A debittered yeast powder having a dispersibility of 60 to 100% allows the dispersion of said powder in liquid systems without forming blocks or aggregates. In a particular embodiment, the invention relates to a debittered yeast powder as defined above, said debittered yeast powder having:▪ a water retention capacity of 2.0 to 4.0 g water / g of said debittered yeast powder, in particular 3.0 to 3.5 g water / g of said debittered yeast powder; and▪ a water activity of 0.30 to 0.62. The term "water retention capacity" refers to the amount of water that the powder can absorb per gram. The method of measuring the water retention capacity does not influence the result obtained, and the water retention capacity can be measured using a method known to those skilled in the art (as an example see Nguyen DQ et al., Sch. J. Eng. Tech.,20153(4B)402-412) "2.0 to 4.0 g of water / g of said debittered yeast powder" means: 2.0 to 2.5 g of water / g of said debittered yeast powder, 2.5 to 3.0 g of water / g of said debittered yeast powder, 3.0 to 3.5 g of water / g of said debittered yeast powder and 3.5 to 4.0 g of water / g of said debittered yeast powder. The term "water activity" means the water vapor pressure of a gaseous atmosphere in equilibrium with the medium (here, the debittered yeast powder) divided by the saturation vapor pressure of that atmosphere at the same temperature. This represents the amount of free water available for biological reactions. Microorganisms do not grow at a water activity below 0.7. The method of measuring the water activity does not influence the result obtained, and the water activity can be measured using a device known to those skilled in the art, by way of example and in a non-limiting manner,using a Novasina LabMaster-aw device marketed by Grosseron. A debittered yeast powder having a water activity of from 0.30 to 0.62 makes it possible to obtain a powder that is easily preserved because microorganisms cannot develop inside it. By "from 0.30 to 0.62" is meant: from 0.30 to 0.35, from 0.35 to 0.40, from 0.40 to 0.45, from 0.45 to 0.50, from 0.50 to 0.55, from 0.55 to 0.60 and from 0.60 to 0.62. In a particular embodiment, the invention relates to a debittered yeast powder as defined above, said debittered yeast powder having:▪ an emulsifying activity of from 40 to 80 g / m², in particular from 55 to 65, g / m² ; et▪ an emulsifying stability of 75 to 100 minutes, in particular 85 to 95 minutes. By “emulsifying activity” we mean the surface of the interface stabilized by a given concentration of matter (here in debittered yeast powder). The method of measuring the emulsifying activity does not influence the result obtained, and the emulsifying activity can be measured using a method known to those skilled in the art (For example, see Yang et al., Int. J. of Bio. Macromolecules (2022), 222, (8), 1700-1708) By "from 40 to 80 g / m²", we mean: from 40 to 45 g / m², from 45 to 50 g / m², from 50 to 55 g / m², from 55 to 60 g / m², from 60 to 65 g / m², from 65 to 70 g / m², from 70 to 75 g / m², from 75 to 80 g / m². A debittered yeast powder having an activity Emulsifier of 40 to 80 g / m² allows to give a uniform texture to a food product. It also helps to improve the mouthfeel, palatability and uniform mixing of ingredients.By "emulsifying stability" is meant the maximum duration of the holding in the form of an emulsion of two immiscible phases before the visual observation of the separation into two phases of said emulsion. The method of measuring the emulsifying stability does not influence the result obtained. By "75 to 100 minutes" is meant: from 75 to 80 minutes, from 80 to 85 minutes, from 85 to 90 minutes, from 90 to 95 minutes, from 95 to 100 minutes. A debittered yeast powder having an emulsifying stability of between 75 and 100 minutes allows the use of this powder in food preparations requiring stability of the emulsion during its preparation, for example, in vegetable preparations. The debittered yeast powder has an emulsifying capacity allowing it to form a physically stable emulsion: - from 5% incorporation of debittered yeast powder - for water:oil ratios of 1 to 3.5.The emulsifying activity can be measured using a visual method known to those skilled in the art (Chang et al. (2014). J Food Process Eng, 37: 229-236). This method of measuring the emulsifying activity does not influence the result obtained. In a particular embodiment, the invention relates to a debittered yeast powder as defined above, said debittered yeast powder having a minimum gelling concentration of 15 to 30%, in particular 23 to 28%, said minimum gelling concentration being expressed as a mass percentage. By "minimum gelling concentration" is meant the minimum concentration in solution of the debittered yeast powder to allow the passage of said solution from a fluid state to a gel state.The minimum gelling concentration is evaluated according to the following protocol: Suspensions of debittered yeast powder samples (2, 4, 6, 8, 10, 12, 15, 18% for example) were prepared in 10 ml of distilled water. The test tubes containing these suspensions were then heated for one hour in a boiling water bath (100°C), followed by cooling under cold tap water. The test tubes are then cooled for 3 hours at (3-4°C). The minimum gelling concentration is determined as that where the sample did not fall or slide after inversion of the test tube. The method of measuring the minimum gelling concentration does not influence the result obtained. By "15 to 30%" we mean: 15 to 20%, 20 to 25%, 25 to 30%.A debittered yeast powder with a minimum gelling concentration of 15 to 30% allows the formation of protein matrices contributing to the viscoelastic and solid properties of foods. In a particular embodiment, the invention relates to a debittered yeast powder as defined above, said debittered yeast powder having a protein concentration of 25 to 60%, in particular 45 to 55%. The method of measuring the protein concentration does not influence the result obtained, and the protein concentration can be measured using a method known to those skilled in the art (for example the Kjeldahl method). By "25 to 60%" is meant: 25 to 30%, 30 to 35%, 35 to 40%, 40 to 45%, 45 to 50%, 50 to 55%, 55 to 60%.In a particular embodiment, the invention relates to a debittered yeast powder as defined above, said debittered yeast powder having a dispersibility of from 60 to 100%, in particular from 75 to 95%, and / or, ▪a water retention capacity of from 2.0 to 4.0 g of water / g of said debittered yeast powder, in particular from 3.0 to 3.5 g of water / g of said debittered yeast powder; and▪ a water activity of from 0.30 to 0.62, and / or, ▪an emulsifying activity of from 40 to 80 g / m², in particular from 55 to 65. g / m² ; et▪ an emulsifying stability of 75 to 100 minutes, in particular 85 to 95 minutes, and / or, having a minimum gelling concentration of 15 to 30%, in particular 23 to 28%, said minimum gelling concentration being expressed as a mass percentage, and / or, having a protein concentration of 25 to 60%, in particular 45 to 55%. In a particular embodiment, the invention relates to a debittered yeast powder as defined above, said debittered yeast powder comprising:▪ from 20 to 30 mg of histidine / g of protein, in particular 22 mg of histidine / g of protein; ▪ from 40 to 50 mg of isoleucine / g of protein, in particular 47 mg of isoleucine / g of protein; ▪70 to 80 mg leucine / g protein, in particular 72 mg leucine / g protein; ▪70 to 80 mg lysine / g protein, in particular 78 mg lysine / g protein;o 20 to 60 mg of a methionine-cysteine ​​mixture / g protein,in particular 28 mg of a methionine-cysteine ​​mixture / g of protein; or 50 to 60 mg of a methionine-cysteine ​​mixture / g of protein, in particular 54 mg of a methionine-cysteine ​​mixture / g of protein; ▪ from 75 to 85 mg of a phenylalanine-tyrosine mixture / g of protein, in particular 81 mg of a phenylalanine-tyrosine mixture / g of protein; ▪ from 45 to 55 mg of threonine / g of protein, in particular 51 mg of threonine / g of protein; ▪ from 10 to 20 mg of tryptophan / g of protein, in particular 15 mg of tryptophan / g of protein; and ▪from 50 to 60 mg of valine / g of protein, in particular 57 mg of valine / g of protein. The debittered yeast powder of the invention has the properties defined above, namely:▪ from 0.002 to 0.400 mg of alpha acids / g of debittered yeast, preferably from 0.050 to 0.200 mg of alpha acids / g of debittered yeast, said alpha acids being in particular cohumulone, adhumulone and humulone, ▪from 0.001 to 0.300 mg of beta acids / g of debittered yeast,preferably from 0.001 to 0.010 mg of beta acids / g of debittered yeasts, said beta acids being in particular lupulone, adlupulone and colupulone, ▪from 3 to 8 mg of purines / g of debittered yeasts, in particular 5 mg of purines / g of debittered yeasts, said purines being in particular adenine, guanine, adenosine, hypoxanthine, guanosine and xanthine, ▪a dispersibility of from 60 to 100%, in particular from 75 to 95%, ▪a water retention capacity of from 2.0 to 4.0 g of water / g of said debittered yeast powder, in particular from 3.0 to 3.5 g of water / g of said yeast powder debittered, ▪a water activity of 0.30 to 0.62,▪ an emulsifying activity of 40 to 80 g / m², in particular 55 to 65 g / m², ▪an emulsifying stability of 75 to 100 minutes, in particular 85 to 95 minutes, ▪a minimum gelling concentration of 15 to 30%, in particular 23 to 28%, ▪a protein concentration of 25 to 60%,in particular from 45 to 55%.The invention also relates to a method for manufacturing a debittered yeast powder as defined above. Another aspect of the invention also relates to a method for manufacturing a debittered yeast powder, collected, optionally washed and inactivated, dried and optionally ground, said method comprising at least the steps of:a. debittering comprising at least the steps: i) of culturing a brewing yeast resulting from brewing fermentation, in particular chosen from: Saccharomyces cerevisiae and Saccharomyces pastorianus inoculated, at a rate of 10 to 100 g / L in a bioreactor, said culturing being carried out in a transition medium under conditions: − of agitation of between 25 and 1000 rpm, − of temperature of between 4 and 37°C, in particular of between 7 and 32°C, said transition medium comprising: − from 0 to 50 g / L, of an ammonium or urea salt, corn solubles, protamylasse − from 0 to 10 g / L,of a potassium salt,− from 0 to 5 g / L, of a magnesium salt, in particular MgSO4,− from 0 to 30 gglucose equivalent / L, of a carbon source chosen from: glucose, sucrose, maltose, maltotriose, fructose, mannose, galactose, raffinose, trehalose, glycerol, beet molasses, onion crop residues, beer production waste consisting of or comprising the supernatant resulting from the sedimentation of a fermented and drawn-off brewing yeast, brewery spent grain, potato residue, bread production waste, dates, cane molasses, milling by-products, food industry by-products, and mixtures thereof, said carbon source being optionally enzymatically treated, in particular by an α-amylase or an amyloglucosidase, and −from 0 to 15 g / L of inactivated microorganism extract,and whose pH is regulated and is between 3 and 10; andii) fed-batch fermentation, after exhaustion of the carbon source of said transition medium, to obtain debittered yeasts, said fed-batch being carried out using a feed medium under conditions:− of agitation of said transition medium between 100 and 1000 rpm, and − of temperature between 20 and 35°C, said feed medium being added at a flow rate, in particular at a constant flow rate, between 0.01 and 0.50 gglucose equivalent / g, biomass / h, for a period of 6 to 72 hours, said feeding medium comprising:− from 0 to 50 g / L of an ammonium or urea salt, corn solubles, protamylasse, − from 0 to 10 g / L of a potassium salt,− from 0 to 5 g / L of a magnesium salt, in particular MgSO4,− from 50 to 500 g glucose equivalent / L, of a carbon source chosen from: glucose, sucrose, maltose, fructose, mannose, galactose, raffinose, trehalose, glycerol, maltotriose, ethanol, beet molasses, onion crop residues, beer production waste consisting of or comprising the supernatant from the sedimentation of a yeast fermented and drawn brewery waste, brewery spent grain, potato residue, bread production waste, dates, corn, cane molasses, milling by-products, food industry by-products,and mixtures thereof, said carbon source being optionally enzymatically treated, and− from 0 to 15 g / L of inactivated microorganism extract, and the pH of which is regulated and is between 3 and 10, and optionally, iii) a step of continuous racking or supplementation with a supplemented medium containing a brewing yeast resulting from continuous brewing fermentation, and continuous racking, to obtain debittered yeasts;b. collection of said debittered yeasts by filtration or centrifugation or simple decantation to obtain debittered and collected yeasts;c. optionally washing of said debittered and collected yeasts to obtain debittered, collected and optionally washed yeasts;d. drying said debittered, collected, optionally washed yeasts, to obtain a powder of debittered, collected, optionally washed, and dried yeasts having a dry matter content of 90 to 100%,said drying being carried out for a period of time of from 0.5 to 180 min, at a temperature of from 40 to 150°C; and optionally a step of inactivating said debittered yeasts obtained at the end of step a, said debittered and collected yeasts obtained at the end of step b, or said debittered, collected and optionally washed yeasts obtained at the end of step c, to obtain debittered and inactivated yeasts, debittered collected and inactivated yeasts or debittered, collected, inactivated and optionally washed yeasts, said inactivation being carried out in an aqueous medium comprising from 1 to 30% of dry mass, for a period of time of from 0.05 seconds to 30 min, at a temperature of from 50 to 95°C or from 50 to 80°C; and optionally grinding said debittered, collected, optionally washed, inactivated and dried yeast powder to obtain a debittered, collected yeast powder,optionally washed, inactivated, dried and optionally ground having a median particle size of 5 to 25 µm, said debittered yeast powder, collected, optionally washed, inactivated, dried and optionally ground comprises:▪ from 0.002 to 0.400 mg of alpha acids / g of debittered yeasts, said alpha acids being in particular cohumulone, adhumulone and humulone; and / or ▪ from 0.001 to 0.300 mg of beta acids / g of debittered yeasts, said beta acids being in particular lupulone, adlupulone and colupulone. In a particular embodiment, the invention relates to a manufacturing method as defined above of a powder of debittered yeasts, collected, optionally washed, inactivated, dried and possibly ground, in which said inactivation is carried out for a period of 0.05 seconds to 10 minutes. In a particular embodiment,the invention relates to a manufacturing process as defined above of a powder of debittered, collected, optionally washed, inactivated, dried and optionally ground yeasts, in which said inactivation is carried out for a period of 0.5 to 10 minutes. In a particular embodiment, the invention relates to a manufacturing process as defined above of a powder of debittered, collected, optionally washed, inactivated, dried and optionally ground yeasts, in which said inactivation is carried out for a period of 0.5 to 30 minutes.In the expression "debittered, collected, optionally washed and inactivated, dried and optionally ground yeasts powder", it is the yeasts which are debittered, collected,optionally washed and inactivated and it is the powder which is dried and possibly ground. Step i) of culturing a brewing yeast inoculated in a transition medium is carried out at a "temperature of 4 to 37°C", meaning: 4 to 8°C, 8 to 12°C, 12 to 16°C, 16 to 20°C, 20 to 24°C, 24 to 28°C, 28 to 32°C and 32 to 37°C. Step ii) of fed-batch fermentation using a medium for feeding said brewing yeast is carried out at a "temperature of 20 to 35°C", meaning: 20 to 25°C, 25 to 30°C and 30 to 35°C. The fed-batch fermentation is still in progress during step iii) of continuous racking or supplementation with a supplemented medium containing brewing yeast from continuous brewing fermentation,and continuous racking. The supplemented medium is a liquid medium containing a brewing yeast from brewing fermentation. Step iii) of continuous racking has the advantage of extending the duration of each production cycle and thus reducing the costs associated with setting up, emptying and cleaning a fed-batch mode with equivalent production Step iii) of supplementation with a supplemented medium containing a brewing yeast from continuous brewing fermentation and continuous racking has the advantage of extending the duration of each production cycle and thus reducing the costs associated with setting up, emptying and cleaning a fed-batch mode with equivalent production The method for manufacturing a debittered, collected and dried yeast powder of the invention comprises: a debittering step a., a collection step b. and,a drying step d. The debittering step a. includes at least:cultivating an inoculated brewing yeast in a transition medium i), and fed-batch fermentation using a feed medium or fed-batch fermentation of said brewing yeast ii).The expression "cultivating" means making a microorganism (here, a brewing yeast) live and proliferate in the culture medium with the aim of increasing the biomass in the bioreactor.The expression "inoculated in a bioreactor" means the action of introducing a microorganism (here, a brewing yeast) into the culture medium of the bioreactor.The expression "from 10 to 100 g / L" means: from 10 to 20 g / L, from 20 to 30 g / L, from 30 to 40 g / L, from 40 to 50 g / L, from 50 to 60 g / L, from 60 at 70 g / L, from 70 to 80 g / L, from 80 to 90 g / L, from 90 to 100 g / L. The expression "from 25 to 1000 rpm" means: from 25 to 100, from 100 to 200 rpm, from 200 to 300 rpm,300 to 400 rpm, 400 to 500 rpm, 500 to 600 rpm, 600 to 700 rpm, 700 to 800 rpm, 800 to 900 rpm, 900 to 1000 rpm.The term "fed-batch fermentation" refers to a fermentation process in which micronutrients and the carbon source are introduced into the bioreactor during the process while the biomass remains inside the bioreactor during the process. During fed-batch fermentation, the transition medium in the bioreactor is supplemented with feed medium continuously to allow the growth of the biomass. The medium formed by the transition medium supplemented with feed medium is called propagation medium. The composition of the propagation medium is not fixed because the supplementation of transition medium as well as the growth of the biomass change its composition at each moment of the process. By "lag exhaustion, l s uc o o u s e rc e q e u iv d has l e ecarbone”, we mean that the carbon source concentration is 0 to 29 g nt / L, in particular from 0 to 10 gglucose equivalent / L.The expression "constant flow rate" means that the flow rate does not vary above or below 10%.The expression "from 6 to 72h" means: from 6 to 12h, from 12 to 18h, from 18 to 24h, from 24 to 30h, from 30 to 36h, from 36 to 42h, from 42 to 48h, from 48 to 54h, from 54 to 60h, from 60 to 66h, from 66 to 72h. The collection step b. consists of collecting the yeasts that have undergone the debittering step.The expression "simple decantation" means the separation of the yeast phase from the aqueous phase (supernatant) The drying step d. consists of removing free water available for biological reactions from the powder in order to reduce its water activity. When drying is carried out by spray drying, a grinding step is not necessary because the result of spray drying is a powder with a median particle size of 5 to 20 µm. When drying is carried out on a plate or with a heating cylinder,a grinding step is necessary to obtain a powder with a median particle size of 5 to 25 µm. The method for manufacturing a powder of debittered, collected, washed and dried yeasts of the invention may comprise: a washing step c. between the collection step b. and the drying step d. The method then comprises: a debittering step a., a collection step b., a drying step d. as defined above and,a washing step c. The optional washing step c. removes residual salts and carbon sources provided by the transition and feed media. It also removes any cell lysis products (cell contents or walls) and metabolites generated by the yeasts. This washing consists of resuspension and concentration of the debittered yeast. The washing step can be repeated a second time if necessary. The amount of water used for this washing step varies from 1.5 to 4 times the weight of the pellet, preferably 2.5 times the weight of the pellet. The term "pellet" refers to the yeasts sedimented in the bottom of a container (which allows the contents of the bioreactor to be withdrawn) after the concentration step carried out by centrifugation. The method for manufacturing a collected, dried and inactivated debittered yeast powder of the invention may comprise an inactivation step at the end of step a.,at the end of step b. or at the end of step c. The process then comprises: a debittering step a., a collection step b., a drying step d. as defined above and, an inactivation step. The optional inactivation step allows the suppression of the biological activity of the yeast under the effect of heat. This step can be carried out for a duration of 0.05 seconds to 10 minutes or 0.5 to 30 minutes. By "from 1 to 30% of dry matter", we mean: from 1 to 5% of dry matter; from 5 to 10% of dry matter; from 10 to 15% of dry matter; from 15 to 20% of dry matter; from 20 to 25% dry matter and from 25 to 30% dry matter.The method for manufacturing a debittered, collected, dried, and ground yeast powder of the invention may comprise a grinding step at the end of the drying step d..The method then comprises: a debittering step a., a collection step b., a drying step d. as defined above and,a grinding step. The optional grinding step makes it possible to give the powder obtained a median particle size of 5 to 25 µm. When said powder has a median particle size of 5 to 25 µm, it is easier to use in food applications than a powder having a median particle size greater than 25 µm. The method for manufacturing a debittered, collected, washed, dried and inactivated yeast powder according to the invention may comprise a washing step c. between the collection step b. and the drying step d. and an inactivation step at the end of step a., at the end of step b. or at the end of step c. The method then comprises: a debittering step a., a collection step b., a washing step c., a drying step d. and, an inactivation step as defined above. The process for manufacturing a powder of debittered, collected, washed yeasts,dried and ground according to the invention may comprise a washing step c. between the collection step b. and the drying step d. and a grinding step at the end of the drying step d.. The method then comprises: a debittering step a., a collection step b., a washing step c., a drying step d. and, a grinding step as defined above. The method for manufacturing a powder of collected, dried, inactivated and ground debittered yeasts according to the invention may comprise an inactivation step at the end of step a., at the end of step b. or at the end of step c. and a grinding step at the end of the drying step d..The method then comprises: a debittering step a., a collection step b., a drying step d., an inactivation step and, a grinding step as defined above. The method for manufacturing a powder of debittered yeasts collected, washed, dried,inactivated and ground according to the invention may comprise a washing step c. between the collection step b. and the drying step d., an inactivation step at the end of step a., at the end of step b. or at the end of step c., and a grinding step at the end of the drying step d.. The method then comprises: a debittering step a., a collection step b., a washing step c., a drying step d., an inactivation step and, a grinding step as defined above. In a particular embodiment, the invention relates to a manufacturing method as defined above of a powder of debittered yeasts, collected, optionally washed and inactivated, dried and optionally ground, said powder of debittered yeasts, collected, optionally washed, inactivated, dried and optionally ground further comprises: ▪from 3 to 8 mg of purines / g of debittered yeasts, said purines being in particular adenine, guanine, adenosine,hypoxanthine, guanosine and xanthine. The method according to the invention may contain a step of inoculation of the brewing yeast prior to the cultivation of said brewing yeast. In a particular embodiment, the invention relates to a method for manufacturing as defined above a powder of debittered yeasts, collected, optionally washed and inactivated, dried and optionally ground, said method comprising at least the steps of:a. debittering comprising at least the steps: ε) inoculation of 10 to 100 g / L, in particular 20 to 50 g / L (and more particularly 40 g / L), of a brewing yeast resulting from brewing fermentation, in particular chosen from: Saccharomycescerevisiae and Saccharomyces pastorianus, in a bioreactor, i) culturing said brewing yeast, said culturing being carried out in a transition medium under conditions: − stirring of between 25 and 1000 rpm, in particular 200 and 800 rpm,and −temperatures of 4 to 37°C, in particular 7 to 32°C,said transition medium comprising:− from 0 to 50 g / L, in particular 0 to 30 g / L, and more particularly 0 to 10 g / L, of an ammonium salt chosen from: (NH4)2HPO4, (NH4)2SO4 and their mixture, or urea, corn solubles, protamylasse, −from 0 to 10 g / L, in particular 0 to 5 g / L, of a potassium salt chosen from: KH2PO4, K2HPO4 and their mixture,− from 0 to 5 g / L, in particular 0 to 2 g / L, and more particularly 0 to 1 g / L, of a magnesium salt, in particular MgSO4,− from 0 to 30 gglucose equivalent / L, in particular from 0 to 5 gglucose equivalent / L, of a carbon source chosen from: glucose, sucrose, maltose, maltotriose, fructose, mannose, galactose, raffinose, trehalose, glycerol, beet molasses, onion crop residues,beer production waste consisting of or comprising the supernatant resulting from the sedimentation of a fermented and drawn-off brewing yeast, brewery spent grain, potato residue, bread production waste, dates, cane molasses, milling by-products, agri-food industry by-products, and mixtures thereof, said carbon source optionally being enzymatically treated, in particular by an α-amylase or an amyloglucosidase, and − from 0 to 15 g / L, in particular from 0 to 1 g / L, of inactivated microorganism extract, and the pH of which is regulated and is between 3 and 10, in particular between 4 and 7; and ii) fed-batch fermentation, after exhaustion of the carbon source of said transition medium, to obtain debittered yeasts, said fed-batch being carried out using a feed medium under conditions:− of agitation of said transition medium between 100 and 1000 rpm,in particular from 200 to 800 rpm, and −at a temperature of from 20 to 35°C, said feed medium being added to, 0,50 ggl at a flow rate, in particular at a constant flow rate, of between 0.01 ucose equivalent / glucose equivalent / g of biomass / h, in particular between 0.10 and 0.15 g lent / g of biomass / h, for a period of 6 to 72 hours, in particular 24 to 48 hours, said feeding medium comprising:− from 0 to 50 g / L, in particular from 0 to 30 g / L, and more particularly from 0 to 10 g / L, of an ammonium salt chosen from: (NH4)2HPO4, (NH4)2SO4 and their mixture, or urea, corn solubles, protamylasse, − from 0 to 10 g / L, in particular from 0 to 5 g / L, of a potassium salt chosen from: KH2PO4, K2HPO4 and their mixture,− from 0 to 5 g / L, in particular from 0 to 2 g / L, and more particularly from 0 to 1 g / L, of a magnesium salt, in particular MgSO4,− of glucose equivalent glucose quiv 5a le 0n tat 500 g / L, in particular from 150 to 250 g / L, preferably from 175 to 225 gglucose equivalent / L, of a carbon source chosen from: glucose, sucrose, maltose, fructose, mannose, galactose, raffinose, trehalose, glycerol, maltotriose, ethanol, beet molasses, onion crop residues, beer production waste consisting of or comprising the supernatant from the sedimentation of a fermented and drawn-off brewing yeast, brewery spent grain, potato residue, bread production waste, dates, cane molasses, milling co-products, food industry co-products, and mixtures thereof, said carbon source being optionally enzymatically treated, in particular by a α-amylase or an amyloglucosidase or a protease, and− from 0 to 15 g / L, in particular from 0 to 1 g / L, of inactivated microorganism extract, and whose pH is regulated and is between 3 and 10, inparticular from 4 to 7, and optionally, iii) a step of continuous racking or supplementation with a supplemented medium containing a brewing yeast resulting from continuous brewing fermentation, and continuous racking, to obtain debittered yeasts;b. collection of said debittered yeasts by filtration or centrifugation or simple decantation to obtain debittered and collected yeasts;c. optionally washing of said debittered and collected yeasts to obtain debittered, collected and optionally washed yeasts;d. drying said debittered, collected, optionally washed yeasts, to obtain a powder of debittered, collected, optionally washed, and dried yeasts having a dry matter content of 90 to 100%, in particular 92 to 98, said drying being carried out for a period of 0.5 to 180 min, in particular 120 min, at a temperature of 40 to 150°C, in particular 50°C;andoptionally a step of inactivating said debittered yeasts obtained at the end of step a, said debittered and collected yeasts obtained at the end of step b, or said debittered, collected and optionally washed yeasts obtained at the end of step c, to obtain debittered and inactivated yeasts, debittered collected and inactivated yeasts or debittered, collected, inactivated and optionally washed yeasts, said inactivation being carried out in an aqueous medium comprising from 1 to 30% of dry mass, in particular 10% of dry mass, for a period of from 0.5 to 30 min, in particular 15 min, at a temperature of from 50 to 95°C or from 50 to 80°C, in particular 60°C; andoptionally grinding said debittered, collected, optionally washed, inactivated and dried yeast powder to obtain a debittered, collected, optionally washed, inactivated, dried and optionally ground yeast powderhaving a median particle size of 5 to 25 µm, said powder of debittered yeasts, collected, optionally washed, inactivated, dried and possibly ground comprises:▪ from 0.002 to 0.400 mg of alpha acids / g of debittered yeasts, preferably from 0.050 to 0.200 mg of alpha acids / g of debittered yeasts, said alpha acids being in particular cohumulone, adhumulone and humulone; and / or, ▪ from 0.001 to 0.300 mg of beta acids / g of debittered yeasts, preferably from 0.001 to 0.010 mg of beta acids / g of debittered yeasts, said beta acids being in particular lupulone, adlupulone and colupulone. In a particular embodiment, the invention relates to a manufacturing method as defined above of a powder of debittered yeasts, collected, optionally washed and inactivated, dried and optionally ground, said powder of debittered yeasts, collected, optionally washed, inactivated, dried and optionally ground further comprises: ▪of3 to 8 mg of purines / g of debittered yeasts, said purines being in particular adenine, guanine, adenosine, hypoxanthine, guanosine and xanthine.In a particular embodiment, the invention relates to a manufacturing process as defined above of the debittered yeast powder according to the invention having the following properties, said debittered yeast powder, collected, optionally washed, inactivated, dried and optionally ground comprises:▪ from 0.002 to 0.400 mg of alpha acids / g of debittered yeasts, preferably from 0.050 to 0.200 mg of alpha acids / g of debittered yeasts, said alpha acids being in particular cohumulone, adhumulone and humulone, ▪ from 0.001 to 0.300 mg of beta acids / g of debittered yeasts, preferably from 0.001 to 0.010 mg of beta acids / g of debittered yeasts, said beta acids being in particular lupulone, adlupulone and colupulone, ▪a dispersibility of 60 to 100%, in particular 75 to 95%,▪ awater retention capacity of 2.0 to 4.0 g water / g of said debittered yeast powder, in particular 3.0 to 3.5 g water / g of said debittered yeast powder, ▪a water activity of 0.30 to 0.62,▪ an emulsifying activity of 40 to 80 g / m², in particular 55 to 65 g / m², ▪an emulsifying stability of 75 to 100 minutes, in particular 85 to 95 minutes, ▪a minimum gelling concentration of 15 to 30%, in particular 23 to 28%, ▪a protein concentration of 25 to 60%, in particular 45 to 55%.In a particular embodiment, the invention relates to a method as defined above, wherein said culturing step ai) is carried out under pO2 conditions of 0 to 100%, in particular 20 to 60%. The expression "pO2" designates the partial pressure of oxygen, which corresponds to the relative concentration of dissolved oxygen in the fermentation must at saturation. When thepO2 value reaches 100%, then the medium is saturated with oxygen. In this embodiment, the oxygen consumption by the yeasts is not a limiting factor in the transformation of sugars into biomass. In a particular embodiment, the invention relates to a method as defined above, in which said fed-batch step a.ii) is carried out under pO2 conditions of 0 to 100%, in particular 20 to 60% and more particularly 35 to 45%. In this embodiment, the oxygen consumption by the yeasts is not a limiting factor in the transformation of the carbon source provided by the feed medium into biomass. In a particular embodiment, the invention relates to a method as defined above, in which said transition medium is optionally treated enzymatically, in particular by an α-amylase, an amyloglucosidase or a protease.In a particular embodiment, the invention relates to aprocess as defined above, wherein said transition medium is treated enzymatically, in particular by an α-amylase or an amyloglucosidase. In a particular embodiment, the invention relates to a process as defined above, wherein said transition medium is not treated enzymatically. In a particular embodiment, the invention relates to a process as defined above, wherein said transition medium further comprises:▪ mineral salts chosen from: ZnSO4, CaCl2, FeSO4, H3BO3, CuSO4, Na2MoO4, MnCl2, CoCl2, KCl, and mixtures thereof; and / or▪ EDTA; and / or▪ vitamins selected from: vitamin B1 (thiamine), vitamin B2 (riboflavin), vitamin B3, vitamin B5 (calcium pantothenate), vitamin B6, vitamin B7 (inositol), vitamin B8 (biotin), vitamin B10 and mixtures thereof; and / or▪ peptone; and / or▪ Yeast Nitrogen Base (YNB).In one embodimentIn particular, the invention relates to a method as defined above, wherein said feed medium is optionally enzymatically treated, in particular by an α-amylase or an amyloglucosidase or a protease.In a particular embodiment, the invention relates to a method as defined above, wherein said feed medium is enzymatically treated, in particular by an α-amylase or an amyloglucosidase or a protease. In a particular embodiment, the invention relates to a method as defined above, wherein said feed medium is not enzymatically treated. In a particular embodiment, the invention relates to a method as defined above, in which said step a.ii) of culturing is carried out under pO2 conditions of 0 to 100%, in particular 20 to 60% and more particularly 35 to 45%, and / or, in which said fed-batch step a.iii) is carried out inpO2 conditions of from 0 to 100%, in particular from 20 to 60% and more particularly from 35 to 45%, and / or, wherein said transition medium is optionally enzymatically treated. In a particular embodiment, the invention relates to a method as defined above, wherein said feed medium further comprises:▪ mineral salts chosen from: ZnSO4, CaCl2, FeSO4, H3BO3, CuSO4, Na2MoO4, MnCl2, CoCl2, KCl and mixtures thereof; and / or▪ EDTA; and / or▪ vitamins chosen from: vitamin B1 (thiamine), vitamin B2 (riboflavin), vitamin B3, vitamin B5 (calcium pantothenate), vitamin B6, vitamin B7 (inositol), vitamin B8 (biotin), vitamin B10 and mixtures thereof; and / or▪ peptone; and / or▪ Yeast Nitrogen Base (YNB).The method according to the invention may also comprise at least three steps prior to steps a. ε) of inoculation or ai) of culturing. In one embodimentIn a particular embodiment, the invention relates to a method as defined above, said method further comprising and upstream of said step a. ε) of inoculation or ai) of culturing, at least one step I of drawing off a brewing yeast during brewing fermentation, in particular after primary fermentation, to obtain a drawn-off brewing yeast; and optionally at least the steps of: II of sedimentation of said drawn-off brewing yeast to obtain a drawn-off and sedimented brewing yeast, and a supernatant; and / or III of concentration of said drawn-off and sedimented brewing yeast, in particular by elimination of said supernatant, to obtain a drawn-off, sedimented and concentrated brewing yeast of 10 to 25% dry matter, said percentage of dry matter being expressed in mass concentration. The method for manufacturing a debittered, collected and dried yeast powder of the invention further comprises and upstream of said stepa. ε) inoculation or ai) culturing: a drawing-off step I, and optionally a sedimentation step II and / or a concentration step III The method for manufacturing a powder of debittered, collected, washed and dried yeasts of the invention may further comprise and upstream of said step a. ε) inoculation or ai) culturing: a drawing-off step I. The method for manufacturing a powder of debittered, collected, washed and dried yeasts of the invention may further comprise and upstream of said step a. ε) inoculation or ai) culturing: a drawing-off step I, and a sedimentation step II. The method for manufacturing a powder of debittered, collected, washed and dried yeasts of the invention may further comprise and upstream of said step a. ε) inoculation or ai) cultivation: a drawing-off step I, and a concentration step III. The process for manufacturing a debittered yeast powder,collected, washed and dried of the invention may further comprise and upstream of said step a. ε) of inoculation or ai) of culturing: a racking step I, and a sedimentation step II, and a concentration step III. The advantage of using a racked, sedimented and concentrated brewing yeast is to be able to control the supply of fermented must in the medium. In a particular embodiment, the invention relates to a method as defined above, said racked, sedimented and concentrated brewing yeast being a brewing yeast resulting from brewing fermentation. In a particular embodiment, the invention relates to a method as defined above, in which said brewing yeast resulting from brewing fermentation is a brewing yeast racked at the end of primary fermentation having in particular a viability of 60 to 100%, preferably 85 to 95%. By "primary fermentation" is meant the growth stepexponential growth of yeasts, during which the latter converts most of the sugars into alcohol and carbon dioxide. "Viability" means the rate of live yeasts, measured using methylene blue. The method according to the invention can use brewing yeasts from brewing fermentation, which are considered in the state of the art to have a high content of alpha acids, beta acids and purines. In a particular embodiment, the invention relates to a method as defined above, in which said brewing yeast resulting from brewing fermentation comprises:▪ from 0.3 to 15 mg or from 0.3 to 7 mg of alpha acids / g of debittered yeasts, in particular from 0.5 to 1.5 mg of alpha acids / g of debittered yeasts, said alpha acids being in particular cohumulone, adhumulone and humulone;▪ from 0 to 15 mg or from 0.2 to 4 mg of beta acids / g of debittered yeasts, in particular from 0.3 to 0.6 mg of beta acids / g of yeastsdebittered, said beta acids being in particular lupulone, adlupulone and colupulone. Another aspect of the invention relates to a debittered yeast powder capable of being obtained by the manufacturing process as defined above. Description of the figures Figure 1 represents the evolution as a function of time (hours) of the biomass and ethanol of Saccharomyces cerevisae in the bioreactor of Example 1 below. The monitoring of the biomass is represented with triangles, on the abscissa, and is expressed in grams and the accumulation of ethanol is represented with circles, on the abscissa, and is expressed in grams, as a function of time (hours). Figure 2 represents the evolution as a function of time (hours) of the biomass and ethanol of Saccharomyces cerevisae in the bioreactor of Example 2 below. Biomass monitoring is represented with triangles, on the abscissa, and is expressed in grams, and ethanol accumulation is represented with circles, on theabscissa, and is expressed in grams, as a function of time (hour). Figure 3 represents the evolution as a function of time (hours) of the biomass of Saccharomyces cerevisae in the bioreactor of Example 3 below, supplemented with beet molasses. The monitoring of the biomass is represented with triangles, on the abscissa, and is expressed in grams, the accumulation of ethanol is represented with circles, on the abscissa, and is expressed in grams as a function of time (hour). Figure 4 represents the evolution as a function of time (hours): - of the biomass represented by triangles and expressed in grams - of the alpha acid and glucose content, represented with squares and expressed in µg / g of biomass of Saccharomyces cerevisae - and that of ethanol, represented by circles and expressed in grams, in the bioreactor of Example 4 below. Figure 5 represents a general diagram of the manufacturing process of a debittered yeast powder. (1) represents the tankof mixing. (2) represents the heat exchange. (3) represents the decanter centrifuge (if any). (4) represents the debittering. (5) represents the centrifugation. (6) represents the washing (if any) and its repetitions. (7) represents the heat exchange. (8) represents the centrifugation or filtration. (9) represents the drying. (10) represents the grinding. Figure 6 represents a specific diagram of the manufacturing process of a debittered yeast powder. (1) represents the mixing tank. (2) represents the heat exchange. (3) represents the decanter centrifuge (if any). (4) represents the debittering. (5) represents the centrifugation. (6) represents the washing (if any) and its repetitions. (7) represents the heat exchange. (8) represents the centrifugation or filtration. (9) represents the drying. (10) represents the grinding. The letters in parentheses are the operating parameters. (A) corresponds to the transition medium, comprising sulfateammonium phosphate (NH4)2SO4 (10 g / L), potassium phosphate K2HPO4 (5 g / L), MgSO4 (0.8 g / L), yeast extract (1 g / L), glucose (5 g / L), inositol (10 mg / L), thiamine (8 mg / L), riboflavin (2 mg / L), calcium pantothenate (4 mg / L), ZnSO4 (4 mg / L), FeSO4 (10 mg / L) and CaCl2 (100 mg / L), and to the feeding medium, including a carbon source (200 g glucoseequivalent / L), potassium phosphate K2HPO4 (5 g / L) and ammonium sulfate (NH4)2SO4 (25 g / L). (B) corresponds to 20 minutes at 120°C. (C) corresponds to 5 minutes at 3000g. (D) corresponds to a total duration of 48h (2h transition phase and 46h feeding phase, at pO2 = 40%, pH = 5 and T = 30°C) at a flow rate of 0.125 to 0.2 gglucose equivalent / g biomass / h. (E) corresponds to 10 min at 2700g. (F) corresponds to a ratio of water volume / volume of yeast pellet of 2.5. (G) corresponds to 10 min at 60°C. (H) corresponds to 10 min at 2700g. (I) corresponds to 60°C for 2 hours. (J) corresponds to grinding with an ultracentrifugal mill with a 0.12 mm sieve and a speed of 1500 rpm. Figure 7 represents the evolution as a function of time (hours) of the biomass and ethanol of Saccharomyces cerevisae in the bioreactor of Example 16 below.The biomass monitoring is represented with triangles on the abscissa, and is expressed in grams, and the accumulation of ethanol is represented with circles, on the abscissa and is expressed in grams, as a function of time (hour). Figure 8 represents the evolution as a function of time (hours) of the biomass and the alpha acid content of yeasts of Saccharomyces cerevisae in the bioreactor of Example 17 below. The biomass monitoring is represented with triangles, on the abscissa, and is expressed in grams, and the alpha acid content of yeasts is represented with circles, on the abscissa, and is expressed in grams, as a function of time (hour). Examples The bitterness of yeasts is linked to the adsorption on their wall of bitter molecules during the fermentation of beer.The debittering process aims to transfer these used brewery yeasts into a growth-friendly environment, by gradually adding a feeding medium, in order to propagate a new yeast biomass and thus reduce the concentration of bitter molecules to the perception threshold. The objective of the experiment described in this document is to propagate the biomass of the yeast Saccharomyces cerevisae from beer production. To do this, the yeasts are introduced into a bioreactor in a transitional medium that allows control of the physicochemical environment of the culture, and which contains a medium rich in nutrients necessary for the growth of these microorganisms (carbon, nitrogen, phosphate, potassium, magnesium, sulfate, growth factor, etc.).EXAMPLE 1 Biomass propagation with glucose Spent Brewer's Yeast (SBY) was obtained by fermentation (7 days) of a malt extract wort (175 g / L for 20 total liters) supplemented with 0.195 mg / mL of hop extract, inoculated with 2 g / L of Saccharomyces cerevisae US-05. After 7 days of fermentation, the yeasts were drawn off into a sterile flask from the bottom of the tank and then left to settle for 12 hours at 4°C. This process aims to replicate brewing fermentation and the brewery yeast deposit. The supernatant was then removed to concentrate the yeasts, which were then inoculated into the bioreactor at a concentration of 20 g / L. The initial transition medium is composed of milliQ water (1L), ammonium sulfate (NH4)2SO4 (18 g), potassium phosphate KH2PO4 (2.944 g), MgSO4 (0.81 g), yeast extract (1 g) and glucose (5 g).Each of these compounds was autoclaved separately upstream to ensure its sterility. The physicochemical parameters of the bioreactor were set at pH=5, automatically regulated using a probe by a base solution (NaOH at 1 mol / L), a temperature of 30°C, a dissolved oxygen pressure of 40%, stirring between 100 and 800 rotations per minute related to the measured dissolved oxygen pressure value. From 2 hours of run (which occurs from the contact of the yeasts with the medium until the moment when the debittered product is obtained), the feed medium, prepared and autoclaved at 200 g / L of glucose was added at a rate of 0.05 g. glucose / g levure / h between 2 and 14h then 0.25 g glucose / g levure / h between 14h and 38h (final time). Throughout the run, the increase in biomass was assessed by measuring the optical density (OD) at 600 nm using a spectrophotometer and by measuring the dry weight (washing, centrifugation, drying for 2h at 105°C then weighing a 10mL sample of the propagation medium). The ethanol concentration in the medium was assessed using an enzymatic ethanol assay kit marketed by Oenolab Diagnostics. The residual glucose concentration was measured using Quantofix® test strips marketed by Macherey-Nagel. The quantification of the contaminating bacterial flora (from SBY) was assessed by counting on Petri dishes (Plate Count Agar (PCA), marketed by Biokar®).After 39 hours of the run, the yeasts were collected and centrifuged in 250 mL autoclaved plastic bottles, then washed 3 times with sterile milliQ water to remove salts, carbon sources from the feeding and transition media, possible cell lysis products and metabolites from the propagation medium. They were then resuspended in sterile milliQ water to obtain a 10% dry mass solution and were inactivated by placing them at a temperature of 60°C for 15 minutes. They were then centrifuged and then dried in an oven at 50°C for 2 hours and finally ground in a grinder. The extraction and quantification of glutathione were carried out according to patent EP1706478B1. 10 mL of 0.1 N HCl was added to a centrifuge tube containing 0.4 g of yeast from the process. A suspension was obtained by shaking regularly for 60 minutes at room temperature.The sample was centrifuged at 8000 RPM for 5 minutes. The supernatant was collected for glutathione quantification. For the assay, 0.1 ml of supernatant was added to 4.9 ml of DTNB reagent (5,5-dithio-bis-(2-nitrobenzoic acid). After mixing and 10 minutes of incubation at 25°C, the absorbance was measured at 412 nm. The concentration was calculated using a calibration curve and the equation indicated in patent EP1706478B1 (example 1). Results Figure 1 represents an example of the propagation of brewer's yeast in a bioreactor for its debittering. Growth was enabled by the nutrients initially present in the culture medium and by rigorous control of the physicochemical parameters (temperature, pH, oxygenation, agitation). The growth rate was controlled by the addition of the feeding medium whose carbon source (here, glucose) is converted into biomass. 43.6 grams of S. yeasts.cerevisae, from an initial biomass of 19.4 g, were produced under these conditions, a multiplication of 2.24. The initial 5 grams of glucose were consumed by the yeasts in the first 2 hours of the run. From 2 hours, the feeding medium was added. The addition rate is 0.05 between 2 and 14 hours and then 0.25 between 14 hours and 38 hours (final time) and allows a conversion efficiency of the carbon source into biomass of 0.25. Adding the carbon source gradually through the feeding medium ensures a low quantity of carbon source (here, glucose) instantaneously in the bioreactor and therefore avoids the accumulation of glucose, which can lead to the accumulation of ethanol, a product of yeast metabolism, and therefore an inhibition of yeast propagation. Ten grams of ethanol were initially present in the culture medium, which comes from the beer medium inoculated with the yeasts.After 14 hours, 5 grams of ethanol were consumed by the yeasts, which was also used as a carbon source for yeast propagation. Increasing the feed medium flow rate from 2 p.m. led to the accumulation of ethanol in the bioreactor, which was then re-consumed by the yeasts until the end of the run. The measured glutathione content was 9.11 mg glutathione / g yeast. EXAMPLE 2 Biomass propagation with glucose at 20L scale Spent Brewer's Yeast (SBY) was obtained by fermentation (7 days) of a malt extract wort (175 g / L for 20 total liters) supplemented with 0.195 mg / mL of hop extract, inoculated with 2g / L of Saccharomyces cerevisae US-05. After 7 days of fermentation, the yeasts were drawn off into a sterile flask from the bottom of the tank, then left to settle for 12 hours at 4°C.This process aims to replicate brewery fermentation and the yeast deposit of breweries. The supernatant was then removed to concentrate the yeasts, which were then inoculated into the bioreactor at a concentration of 20 g / L. The initial transition medium is composed of milliQ water (8L), ammonium phosphate (NH4)2PO4 (80 g), potassium phosphate KH2PO4 (40 g), MgSO4 (6.48 g), yeast extract (8g) and sucrose (40g). Each of these compounds was autoclaved separately upstream to ensure its sterility. The physicochemical parameters of the bioreactor were set at pH=5, automatically regulated using a probe by a base solution (NaOH at 1 mol / L), a temperature of 30°C, an incoming air flow rate of 10 L / minute, and agitation at 800 RPM. Dissolved oxygen pressure is measured by a probe added to the bioreactor. The feed medium is prepared. 7.2 liters of a 222 g / L sucrose solution is autoclaved.It is then supplemented with 400 mL of a 500 g / L (NH4)2PO4 solution and 400 mL of a 100 g / L KH2PO4 solution, previously sterilized. From 2 hours of run, (which occurs from the contact of the yeasts with the medium until the moment when the debittered product is obtained) the feed is set up at a rate of 0.15 gglucose equivalent / g. levure / h up to 48h, corresponding to the end of the run. Throughout the run, the increase in biomass was assessed by measuring the optical density (OD) at 600 nm using a spectrophotometer and by measuring the dry weight (washing, centrifugation, drying for 3h at 105°C then weighing a 10mL sample of the propagation medium). The ethanol concentration in the medium was assessed using an enzymatic ethanol assay kit marketed by Oenolab. The residual glucose concentration was measured using Quantofix® reagent strips marketed by Macherey-Nagel. The quantification of the contaminating bacterial flora (from the SBY) was assessed by counting on Petri dishes (Plate Count Agar (PCA), marketed by Biokar®).After 48 hours of the run, the yeasts were collected and centrifuged in autoclaved 400 mL plastic bottles, then washed 3 times with sterile milliQ water to remove salts, carbon sources from the feed and transition media, possible cell lysis products and metabolites from the propagation medium. They were then resuspended in sterile milliQ water to obtain a 10% dry mass solution and were inactivated by placing them at a temperature of 60°C for 15 minutes. They were then centrifuged and then dried in an oven at 50°C for 2 hours and finally ground in a grinder. Results Figure 2 represents an example of the propagation of brewer's yeasts in a bioreactor for debittering. Growth was enabled by the nutrients initially present in the culture medium and by rigorous control of the physicochemical parameters (temperature, pH, agitation).The growth rate was controlled by the addition of the feed medium, whose carbon source (here, sucrose) is converted into biomass. 357 grams of S. cerevisae yeast, from an initial biomass of 125.4 g, were produced under these conditions, representing a multiplication of 2.8. The initial 5 grams of sucrose were consumed by the yeasts in the first 2 hours of the run. From 2 hours onwards, the feed medium was added. The addition rate was 0.15 g. glucose / g levure / h between 2 and 48h (final time) and allows a conversion efficiency of the carbon source into biomass of 0.21. Adding the carbon source gradually through the feed medium ensures a low quantity of carbon source (here, sucrose) instantaneously in the bioreactor and therefore avoids the accumulation of sucrose, which can lead to the accumulation of ethanol, a product of yeast metabolism, and therefore an inhibition of yeast propagation. 72.2 grams of ethanol were initially present in the culture medium, which comes from the beer medium inoculated with the yeasts. After 24h, all the ethanol has been consumed by the yeasts, which is also used as a carbon source for yeast propagation. Increasing the feed medium flow rate from 2 p.m. leads to the accumulation of ethanol in the bioreactor.EXAMPLE 3 Biomass propagation with beet molasses Spent Brewers Yeasts (SBY) were obtained by fermentation (7 days) of a malt extract wort (175 g / L for 20 total liters) supplemented with 0.195 mg / mL of hop extract, inoculated with 2 g / L of Saccharomyces cerevisae US-05. After 7 days of fermentation, the yeasts were drawn off into a sterile flask from the bottom of the tank and left to settle for 12 hours at 4°C. This process aims to replicate brewing fermentation and the brewery yeast deposit. The supernatant was then removed to concentrate the yeasts, which were then inoculated into the bioreactor at a concentration of 20 g / L. Beetroot molasses (France Mélasses) were diluted by two to obtain 200 g. glucoseequivalent / L and were then clarified by centrifugation for 40 minutes, at 4000 rotations per minute (RPM) at 15°C. The initial transition medium present in the bioreactor consists of milliQ water (1L), beet molasses at 5 gglucose equivalent / L through the molasses, 5.4g / L of potassium phosphate (KH2PO4) and 11.42 g / L of ammonium sulfate (NH4)2SO4. Each of these compounds was autoclaved separately beforehand to ensure its sterility. The physicochemical parameters of the bioreactor were set at pH=5, automatically regulated using a probe with a base solution (NaOH at 1 mol / L), a temperature of 30°C, a dissolved oxygen pressure of 40%, stirring between 100 and 800 rpm linked to the measured dissolved oxygen pressure value. From 2h d ge l uc r or s e born q , ul ie v ale min t autoclaved feed medium comp bit of 0.4 gglo u c s oé s e é d qe u iv mylebeet molasses diluted to 200 g / L, was added at a rate of 100 nt / g yeast / h. Throughout the run, the increase in biomass was assessed in the same way as in Example 1. After 48 hours of the run, the yeasts were collected, centrifuged and ground in the same way as in Example 1. Results Figure 3 represents an example of the propagation of brewer's yeast in a bioreactor supplemented with beet molasses for debittering. Growth is enabled by the nutrients initially present in the culture medium (transition medium) and by rigorous control of the physicochemical parameters (temperature, pH, oxygenation, agitation, feed rate). The growth rate is controlled by the addition of molasses (feeding medium) whose carbon source (in the form of sucrose) is converted into biomass. 49 grams of S yeast.cerevisae, from an initial biomass of 21 g, were produced under these conditions, a multiplication of 2.34, with a maximum of 57.5 g of yeast produced reached at 30 h (a multiplication factor of 2.74). The initial 5 grams of sucrose were consumed by the yeasts in the first 2 hours of the run. From 2 h onwards, the feeding medium was added. The addition rate was maintained at a target value of 0.4 g glucose equivalent / g. levures / h. Adding the sugar gradually through the feed medium ensures a low amount of carbon source (here, mainly in the form of sucrose) instantly in the bioreactor and therefore avoids the accumulation of sucrose and other sugars, which can lead to the accumulation of ethanol, a product of yeast metabolism, up to the threshold of 20 g / L and therefore an inhibition of yeast propagation. Twelve grams of ethanol are initially present in the culture medium, which comes from the beer medium inoculated with the yeasts. During the first 2 hours, the ethanol initially present is consumed by the yeasts. Then, after the first 20 hours following the activation of the feed medium, the ethanol accumulates until it reaches 50g. From 10 p.m., the ethanol produced is consumed by the yeasts, this being also used as a carbon source for yeast propagation, reaching a final quantity of 14g.EXAMPLE 4 Biomass propagation with glucose and measurement of bitter molecule concentration Spent brewers yeast (SBY) was obtained by fermentation (5 days) of a malt extract wort (175 g / L for 25 total liters) supplemented with 0.12 mg / L of hop extract, inoculated with 2.5 g / L of Saccharomyces cerevisae US-05. This process aims to replicate brewing fermentation and the brewery yeast deposit. After 6 days of fermentation, the yeasts were drawn into a sterile flask from the bottom of the tank and were then inoculated into the 1L bioreactor at a concentration of 20 g / L. The initial transition medium is composed of milliQ water (400 mL), ammonium sulfate (NH4)2SO4 (10 g / L), potassium phosphate KH2PO4 (5 g / L), MgSO4 (0.8 g / L), yeast extract (1 g / L), glucose (5 g / L), inositol 10 mg / L, thiamine 8 mg / L, riboflavin (2 mg / L), calcium pantothenate (4 mg / L), ZnSO4 (4 mg / L), FeSO4 (10 mg / L), CaCl2 (100 mg / L). Each of these compounds was autoclaved separately upstream to ensure its sterility. The physicochemical parameters of the bioreactor were set at pH=5, automatically regulated using a probe by a base solution (KOH at 2 mol / L), a temperature of 30°C, agitation of 900 RPM and an air flow of 1.4 L / h for the first 2 hours then 4 L / h until 8 hours after the start of the run; 8.2 L / h between 8h and 31h after the start of the run and 14 L / H from 31h after the start of the run (pO2 > 15% at all times). From 2h after the start of the run, an autoclaved feeding medium solution composed of 200 g / L glucose, 5 g / L KH2PO4 and 25 g / L (NH4)2SO4 was added at a rate of 0.125 g. glucose / g levure / h until 24h, then the rate was adjusted to 82 mg glucose / g levure / h from 24h, then was increased to 90 mg glucose / g levure / h from 31h. Throughout the run, the increase in biomass was assessed by measuring the dry weight (centrifugation, drying for 2 hours at 105°C and then by weighing a 5mL sample of the propagation medium. The ethanol concentration in the medium was assessed by HPLC (Thermo scientific, Ultimate 3000) coupled with a Shodex refractometer and a Thermo scientific ultraviolet detector at 210nm. An Aminex HPX-87H column (300x7.8mm, Bio-rad Laboratories SA) was used. The injection volume is 20 μL, and the column was maintained at 30°C. The samples were eluted isocratically with a solution of H2SO4 (4 mM) at a flow rate of 0.5mL / min for 30 minutes. The samples were first centrifuged at 4000g for 5min, diluted by half in H2SO4 (4mM) and filtered through 0.2 μm RC filters. Measurement of the concentration of bitter molecules The samples from these tests were analyzed to determine the concentration of bitter molecules.1 g of wet yeast was suspended in 5 mL of a 100:1 [v / v] mixture of methanol and phosphoric acid. Each sample was subjected to ultrasound at room temperature for 30 min, centrifuged at 4000 g for 5 min and then filtered using a 0.2 μm polytetrafluoroethylene (PTFE) filter. The samples were then passed through an HPLC column (accucore™ aQ C18 from Fischer Scientific) using a gradient of acetonitrile and formic acid. A sensory evaluation of the samples was also carried out. The quantification of the contaminating bacterial flora from the SBY was assessed by counting on Petri dishes (PCA counting agar, marketed by Biokar®). Results Figure 4 represents an example of the propagation of brewer's yeast in a bioreactor for its debittering.Growth is enabled by the nutrients initially present in the culture medium and by rigorous control of physicochemical parameters (temperature, pH, oxygenation, agitation). The growth rate is controlled by the addition of glucose (feeding medium) whose carbon is converted into biomass. 28.1 grams of S. cerevisae yeasts were produced under these conditions, from an initial biomass of 7.8 g, a multiplication of 3.6 in 48 hours. The initial 5 grams of glucose were consumed by the yeasts in the first 2 hours of the run. From 2 hours, the feeding medium was added. The flow rate of aj carbon) in biomass of 0.22 g bo i. o u mt a s p se erm / g ge lt unsugar conversion efficiency (source of ucose. Adding sugar gradually through the feed medium ensures a low amount of sugar (here, glucose) instantaneously in the bioreactor and therefore avoids the accumulation of sugars, which can lead to the accumulation of ethanol, a product of yeast metabolism, up to the threshold of 20 g / L and therefore an inhibition of yeast propagation. 7 grams of ethanol are initially present in the culture medium, which comes from the beer medium inoculated with the yeasts. After 24 hours, all the ethanol has been consumed by the yeasts, it also being used as a carbon source for yeast propagation.From 46.5 hours of run, ethanol begins to accumulate in the bioreactor because the yeasts no longer have the necessary nutrient resources in the medium to multiply and the carbon source provided by the feeding medium (glucose) is transformed into ethanol via fermentation metabolism. The alpha acids adsorbed to the yeasts gradually decrease until stabilizing from 30 hours since the start of the process. This decrease is mainly due to the dilution of bitter molecules with regard to the increase in biomass. However, the total alpha acids bound to the yeasts decrease from 2.8 mg at T0 to 1.3 mg at T48 (Figure 1). EXAMPLE 5 Biomass propagation with cane molasses The used brewery yeasts have the same origin and were inoculated in the same way as in Example 3.The cane molasses are diluted by two to obtain 200 g glucose equivalent / L and are then clarified by centrifugation for 40 minutes, at 4000 RPM at 15°C. The initial transition medium present in the bioreactor consists of milliQ water (1L), at 5 g glucose equivalent / L through the molasses, 5.4 g / L of potassium phosphate (KH2PO4) and 11.42 g / L of ammonium sulfate ((NH4)2SO4). Each of these compounds is autoclaved separately upstream to ensure its sterility. The physicochemical parameters of the bioreactor are set at pH=5, automatically regulated by a probe with a base solution (NaOH at 1 mol / L), a temperature of 30°C, a dissolved oxygen pressure of 40%, stirring between 100 and 800 rpm linked to the measured dissolved oxygen pressure value. After 2 hours of run, the autoclaved feed medium composed of cane molasses diluted to 200 gglucose equivalent / L, is added at a rate of 0.4 g of glucose / g of yeast / h.Throughout the run, the increase in biomass was assessed in the same way as in Example 1. After 48h of the run, the yeasts were collected, centrifuged and ground in the same way as in Example 1. EXAMPLE 6 Biomass propagation with onion crop residues The used brewery yeasts have the same provenance and were inoculated in the same way as in Example 3. The onion crop residues are dried for 2h at 70°C, ground using an electric grinder until the particles reach an average particle size of 1 mm. 25g of these onion crop residue particles are resuspended in 100 mL of MilliQ water. Air is bubbled through the solution at 70°C for 1h to remove the sulfur odor.This solution is clarified by centrifugation for 10 minutes, at 40 to 100 gglucos00 RPM at 15°C, to obtain the initial glucose equivalent transit medium present in the bioreactor consists of milliQ water (1L), 5 g / L of the onion crop residue solution, 5.4 g / L of potassium phosphate (KH2PO4) and 11.42 g / L of ammonium sulfate ((NH4)2SO4). Each of these compounds is autoclaved separately beforehand to ensure its sterility. The physicochemical parameters of the bioreactor are set at pH=5, automatically regulated by a probe with a base solution (NaOH at 1 mol / L), a temperature of 30°C, a dissolved oxygen pressure of 40%, stirring between 100 and 800 rpm related to the measured dissolved oxygen pressure value. From 2 hours of run, the autoclaved feed medium composed of onion culture residues diluted to 100 g glucose equivalent / L, is added at a rate of 0.4 g glucose / g yeast / h.Throughout the run, the increase in biomass was assessed in the same way as in Example 1. After 48h of the run, the yeasts were collected, centrifuged and ground in the same way as in Example 1. EXAMPLE 7 Biomass propagation with potato residues The used brewery yeasts have the same provenance and were inoculated in the same way as in Example 3. The potato residues (consisting of potato pulps, peelings) are dried for 2h at 70°C, ground using an electric grinder until the particles reach an average particle size of 1 mm. 40g of these potato residue particles are resuspended in 100 mL of milliQ water. They are then put into contact with the ENDOZYM Brewmix Plus enzymatic mix (α-amylase, protease, cellulase, β-glucanase) at a rate of 25mL / Le, at 60°C, at pH = 6 for 2 hours and at 100 RPM.They are then brought into contact with ENDOZYM AMG (amyloglucosidase from Aspergillus niger, EC 3.2.1.3, unique formula identifier (UFI): NMHW-0930-5S1J-2VF7) at a rate of 500µL / L at 65°C, at pH = 5 for 1h and at 100 RPM. This solution is clarified by centrifugation for 40 minutes, at 4000 RPM at 15°C. The initial transition medium is composed of milliQ water (1L), the hydrolyzed solution of potato residues (5g. glucose / L), ammonium sulfate (NH4)2SO4 (10 g / L), potassium phosphate KH2PO4 (5 g / L), yeast extract (1 g / L). Each of these compounds is autoclaved separately upstream to ensure its sterility. The physicochemical parameters of the bioreactor are set at pH=5, automatically regulated using a probe by a base solution (NaOH at 1 mol / L), a temperature of 30°C, a dissolved oxygen pressure of 40%, stirring between 100 and 800 rpm linked to the measured dissolved oxygen pressure value. From 2 hours of run, the autoclaved feed medium composed of potato residues reaching 100 gglucose equivalent / L, is added at a rate of 0.4 g of glucose / g of yeast / h. EXAMPLE 8 Biomass propagation with beer production deviations The used brewery yeasts had the same provenance and were inoculated in the same way as in Example 2.The beer production gaps are brought into contact with ENDOZYM AMG (amyloglucosidase from Aspergillus niger, EC 3.2.1.3, unique formula identifier (UFI): NMHW-0930-5S1J-2VF7) at a rate of 250µL / L of beer production gaps at 50°C, pH = 5 for 1h30 and 100 RPM. This solution is clarified by centrifugation for 10 minutes, at 4500 RPM at 15°C. It is composed of 10g / L of glucose and 60g / L of ethanol. The initial transition medium present in the bioreactor consists of the hydrolyzed beer gap solution (1L, 10g. glucose / L and 60g / L of ethanol), ammonium sulfate (NH4)2SO4 (10g / L), potassium phosphate KH2PO4 (5g / L), yeast extract (1g / L). Each of these compounds is autoclaved separately upstream to ensure its sterility. The physicochemical parameters of the bioreactor are set at pH=5, automatically regulated using a probe by a base solution (NaOH at 1 mol / L), a temperature of 30°C, a dissolved oxygen pressure of 40%, stirring between 100 and 800 rpm linked to the measured dissolved oxygen pressure value. From 2 hours of run, the autoclaved feed medium composed of beer production deviations diluted to a concentration of 10 g glucose equivalent / L and 60 g / L of ethanol, is added at a rate of 0.4 g of g glucose equivalent / g of yeast / h. Throughout the run, the increase in biomass was evaluated in the same way as in Example 1.After 48h of the run, the yeasts were collected, centrifuged and ground in the same way as in Example 1. EXAMPLE 9 Biomass propagation with beer production gaps as the carbon source of the transition medium, and with beet molasses as the carbon source of the feed medium The used brewery yeasts have the same provenance and were inoculated in the same way as in Example 2. The treatment of the carbon source, the transition medium and the reactor parameters are the same as in Example 9 From 2h of run, the autoclaved feed medium composed of beet molasses diluted to 200 gglucose equivalent / L, was added at a rate of 0.4 gglucose equivalent / g yeast / h. Throughout the run, the increase in biomass was evaluated in the same way as in Example 1. After 48h of the run, the yeasts were collected, centrifuged and ground in the same manner as in Example 1.EXAMPLE 10 Biomass Propagation with DatesThe used brewery yeasts have the same origin and were inoculated in the same way as in Example 3. The dates are heated to 85 °C in MilliQ water, and a sugar extraction is carried out continuously for 45 minutes. The extract produced has a composition of approximately 600 gglucose equivalent / L (the extracted sugars are a mixture of glucose, fructose and sucrose). A dilution is carried out to obtain 100 gglucose equivalent / L. The initial transition medium present in the bioreactor consists of MilliQ water (1 L), 5 g. glucoseequivalent / L via the date solution, ammonium sulfate (NH4)2SO4 (10 g / L), potassium phosphate KH2PO4 (5 g / L), yeast extract (1 g / L). Each of these compounds is autoclaved separately upstream to ensure its sterility. The physicochemical parameters of the bioreactor are set at a pH=5, automatically regulated using a probe by a base solution (NaOH at 1 mol / L), a temperature of 30°C, a dissolved oxygen pressure of 40%, stirring between 100 and 800 rpm linked to the measured dissolved oxygen pressure value. From 2 hours of run, the autoclaved feed medium composed of dates diluted to 100 g glucoseequivalent / L, is added at a rate of 0.4 g of glucose / g of yeast / h. Throughout the run, the increase in biomass was evaluated in the same way as in Example 1. After 48 hours of the run, the yeasts were collected, centrifuged and ground in the same way as in Example 1, then dried in an oven at 50°C for 2 hours and ground in a grinder. EXAMPLE 11 Biomass propagation with milling production gaps The used brewery yeasts have the same origin and were inoculated in the same way as in Example 3. The milling production gaps are ground using a mortar and then an ultracentrifugal grinder (the particles obtained have a median size of less than 0.2 mm) and then diluted in MilliQ water until the particles reach a concentration of 9% by mass in the solution. A pretreatment with sulfuric acid is carried out to improve enzymatic digestibility.Pure sulfuric acid is added at a rate of 1g per 100g of co-product. The solution is then brought into contact with a Novozymes Kit enzyme cocktail for lignocellulosic biomass (NS50013 35U / 100g of co-product, NS50010250U / 100g of co-product, NS50014225U / 100g of co-product, NS50030150U / 100g of co-product) at 50°C, pH = 5.5 for 48h. The solution is then brought into contact with 350 mg / kg of Novozyme brand Liquozyme SC DS at 85°C) pH = 5.8 for 4h. This solution is diluted to obtain 100 gglucose equivalent / L. Le g lu Initial transition medium present in the bioreactor consists of milliQ water (1L), 5g cose / L of the hydrolyzed solution of milling production deviations, ammonium sulfate (NH4)2SO4 (10 g / L), potassium phosphate KH2PO4 (5 g / L), yeast extract (1 g / L). Each of these compounds is autoclaved separately upstream to ensure its sterility. The physicochemical parameters of the bioreactor are set at pH=5, automatically regulated using a probe by a base solution (NaOH at 1 mol / L), a temperature of 30°C, a dissolved oxygen pressure of 40%, stirring between 100 and 800 rpm linked to the measured dissolved oxygen pressure value. From 2 hours of run, the mili ie diluted to 100 gglueu of autoclaved feed composed of the production gaps of the yeast equivalent cose / L, is added at a rate of 0.4 g of glucose / g of yeast / h. Throughout the duration of the run, the increase in biomass was evaluated in the same way as in Example 1.After 48h of the run, the yeasts were collected, centrifuged and ground in the same way as in Example 1. EXAMPLE 12 First example of biomass propagation with bread residues The used brewery yeasts have the same provenance and were inoculated in the same way as in Example 3. The bread residues are dried for 2h at 70°C, ground using an electric grinder until the particles reach an average particle size of 1 mm. 50g of these bread residue particles are resuspended in 100 mL of MilliQ water. They are then brought into contact with ENDOZYM Alphamyl (α-amylase, from Bacillus licheniformis (EC 3.2.1.1)Unique Formula Identifier (UFI): SUM8-JR43-RW1E-8Y5S) at a rate of 25mL / L at 70°C, at pH = 6 for 2h. They are then brought into contact with 500µL / L of ENDOZYM AMG (amyloglucosidase from Aspergillus niger, EC 3.2.1.3, Unique Formula Identifier (UFI): NMHW-0930-5S1J-2VF7) at 50°C, at pH = 5 for 1h and at 100 RPM.This solution is clarified by centrifugation for 40 minutes, at 4000 RPM at 15°C. The initial transition medium is composed of milliQ water (1L), the hydrolyzed solution of bread residues (5g. glucose / L), ammonium sulfate (NH4)2SO4 (10 g / L), potassium phosphate KH2PO4 (5 g / L), yeast extract (1 g / L). Each of these compounds is autoclaved separately upstream to ensure its sterility. The physicochemical parameters of the bioreactor are set at pH=5, automatically regulated using a probe by a base solution (NaOH at 1 mol / L), a temperature of 30°C, a dissolved oxygen pressure of 40%, stirring between 100 and 800 rpm linked to the measured dissolved oxygen pressure value. After 2 hours of run, the autoclaved feed medium composed of the bread residue solution at 100 g glucose equivalent / L, is added at a rate of 0.4 g glucose / g yeast / h. Throughout the run, the increase in biomass was assessed in the same way as in Example 1. After 48 h of the run, the yeasts were collected, centrifuged and ground in the same way as in Example 1.EXAMPLE 13 Biomass propagation using a continuous process Spent Brewer's Yeast (SBY) was obtained by fermentation (7 days) of a malt extract wort (175 g / L for 20 total liters) supplemented with 0.195 mg / mL of hop extract, inoculated with 2 g / L of Saccharomyces cerevisae US-05. After the 7 days of fermentation, the yeasts were drawn off into a sterile flask from the bottom of the tank and then left to settle for 12 hours at 4°C. This process aims to replicate brewing fermentation and the yeast deposit of breweries. The supernatant was then removed to concentrate the yeasts, which were then inoculated into the bioreactor at a concentration of 20 g / L. The initial transition medium is composed of milliQ water (1L), ammonium sulfate (NH4)2SO4 (10 g), potassium phosphate KH2PO4 (5 g), MgSO4 (0.81 g), yeast extract (1 g) and glucose (5 g).Each of these compounds was autoclaved separately upstream to ensure its sterility. The physicochemical parameters of the bioreactor were set at pH=5, automatically regulated using a probe with a base solution (NaOH at 1 mol / L), a temperature of 30°C, a dissolved oxygen pressure of 40%, stirring between 100 and 800 rotations per minute related to the measured dissolved oxygen pressure value. From 2 hours of run (which happens from the contact of the yeasts with the medium until the moment when the debittered product is obtained), the feeding medium, prepared and autoclaved at 200 g / L of glucose, 5 g / L of KH2PO4, 25 g / L of (NH4)2SO4 was added at a flow rate of 0.15 g. glucose / g levure / h (flow rate of 0.25 mL / min). From 12h of run, a second feed medium, composed of SBY at a concentration of 70 g / L is also added at a flow rate of 0.09 mL / min (0.38 g levures / h). From 14h of run, the medium withdrawal is set up at a flow rate of 0.34 mL / min. Throughout the run, the evolution of the biomass was evaluated by measuring the optical density (OD) at 600 nm by a spectrophotometer and by measuring the dry weight (washing, centrifugation, drying for 2h at 105°C then weighing a sample of 10mL of the propagation medium). The ethanol concentration in the medium was evaluated by using an enzymatic ethanol assay kit marketed by Oenolab Diagnostics. The residual glucose concentration was measured by Quantofix® reagent strips marketed by Macherey-Nagel. The quantification of the contaminating bacterial flora (from SBY) was evaluated by counting on Petri dishes (Plate Count Agar (PCA) marketed by Biokar®).As the run progressed, the yeasts were collected and centrifuged in 250 mL autoclaved plastic bottles, then washed 3 times with sterile MilliQ water to remove salts, carbon sources from the feed and transition media, any cell lysis products, and metabolites from the propagation medium. They were then resuspended in sterile MilliQ water to obtain a 10% dry mass solution and inactivated by placing them at a temperature of 60°C for 15 minutes. They were then centrifuged, then dried in an oven at 50°C for 2 hours, and finally ground in a grinder. EXAMPLE 14 Second example of biomass propagation with bread residues The used brewery yeasts came from the same source and were inoculated in the same way as in Example 3.The bread residues are dried for 2 hours at 70°C, ground using an electric grinder until the particles reach an average particle size of 1 mm. 420g of these bread residue particles are resuspended in 1400 mL of MilliQ water and incubated at 90°C for 1 hour at 200 RPM. They are then brought into contact with BREWLYVE HTA α-amylase (Bacillus licheniformis (EC 3.2.1.1) Unique Formula Identifier (UFI): SUM8-JR43-RW1E-8Y5S) marketed by Soufflet at a concentration of 0.6 µL / g for 1 hour 30 minutes at 80°C at pH 6. The solution is then autoclaved for 20 minutes at 121°C. The amyloglucosidase BREWLYVE AGL marketed by Soufflet (from Aspergillus niger, EC 3.2.1.3, Unique Formula Identifier (UFI): NMHW-0930-5S1J-2VF7) and the acid protease BREWLYVE PAC (from Aspergillus niger (EC 3.4.23.18) Unique Formula Identifier (UFI): YRP6-7RY7-CW11-708M) marketed by Soufflet are then added at a respective concentration of 1 and 0.05 µL / g at a temperature of 60 °C and a pH of 3.5 for 8 h. The pH is adjusted by adding approximately 0.01 ml of HCl (25%) per ml of solution. Alternatively, it is possible to use the protease BREWLYVE NP 900 (from Bacillus subtilis (EC 3.4.24.28) Unique Formula Identifier (UFI): XDSK-A6R4-XS1D-UR9P) instead of the acid protease described above. If this protease is used, then the pH is not adjusted by the addition of HCl. This solution is clarified by centrifugation for 20 minutes, at 4500 RPM at 4 °C. The supernatant is then filtered to remove the dense fibrous residue (if necessary). Finally, the solution is autoclaved for 20 min at 121 °C. The initial transition medium is composed of milliQ water (1L), hydrolyzed bread residue solution (5g. glucose / L), ammonium sulfate (NH4)2SO4 2.5g / L, magnesium sulfateMgSO4 (0.81 g / L), yeast extract (1g / L), antifoam marketed by Erol PMC (made up of a mixture of polyether polyols). Each of these compounds is autoclaved separately upstream to ensure its sterility. The physicochemical parameters of the bioreactor are set at pH=5, automatically regulated using a probe by a base solution (NaOH at 1 mol / L), a temperature of 30°C, and stirring set at 900 RPM. From 2h of run, the autoclaved feeding medium composed of the bread residue solution at 200 gglucose equivalent / L, 1 g / L of yeast extract and 2.5 g / L of (NH4)2SO4, is added at a rate of 0.1 g of glucose / g of yeast / h. Throughout the run, the increase in biomass was evaluated in the same way as in Example 1. After 48h of the run, the yeasts were collected, centrifuged and ground in the same way as in Example 1.EXAMPLE 15 Biomass propagation with glucose at 20L scale Spent Brewer's Yeast (SBY) was obtained by fermentation (7 days) of a malt extract wort (125 g / L for 20 total liters) supplemented with 0.12 mg / mL of hop extract, inoculated with 2 g / L of Saccharomyces cerevisae US-05. After the 7 days of fermentation, the yeasts were drawn off into a sterile flask from the bottom of the tank, then left to settle for 12 hours at 4°C. This process aims to replicate brewing fermentation and the yeast deposit of breweries. The supernatant was then removed to concentrate the yeasts, which were then inoculated into the bioreactor at a concentration of 20 g / L. The initial transition medium is composed of milliQ water (8L), ammonium sulfate (NH4)2SO4 (80 g), potassium phosphate KH2PO4 (40 g), MgSO4 (12.8 g), yeast extract (8 g) and sucrose (40 g), Inositol (80 mg), Thiamine (64 mg), Riboflavin (16 mg), Calcium penthotenate (32 mg), ZnSO4 (32 mg), FeSO4 (80 mg), CaCl2 (800 mg). Each of these compounds was autoclaved separately upstream to ensure its sterility. The physicochemical parameters of the bioreactor were set at pH=5, automatically regulated using a probe by a base solution (NaOH at 1 mol / L), a temperature of 30°C, an incoming air flow rate of 10 L / minute, stirring at 800 RPM. The dissolved oxygen pressure is measured by a probe added to the bioreactor. The feed medium is prepared. 7.2 liters of a 222 g / L sucrose solution is autoclaved. It is then supplemented with 400 mL of a 500 g / L (NH4)2SO4 solution and 400 mL of a 100 g / L KH2PO4 solution, previously sterilized. From 2 hours of run (what happens from the contact of the yeasts with the medium until the momion is set up at a flow rate of 0.15 g. glu e c o n s t where the debittered product is obtained), the feed e equivalent / g levure / h up to 48h, corresponding to the end of the run. Throughout the run, the increase in biomass was assessed by measuring the optical density (OD) at 600 nm using a spectrophotometer and by measuring the dry weight (washing, centrifugation, drying for 3h at 105°C then weighing a 10mL sample of the propagation medium). The concentration of ethanol and glucose in the medium was assessed using an enzymatic ethanol assay kit marketed by Oenolab. The quantification of the contaminating bacterial flora (from the SBY) was assessed by counting on Petri dishes (Plate Count Agar (PCA), marketed by BiokarⓇ).After 48 hours of the run, the yeasts were collected and centrifuged in autoclaved 400 mL plastic bottles, then washed 3 times with sterile MilliQ water to remove salts, carbon sources from the feed and transition media, possible cell lysis products and metabolites from the propagation medium. They were then resuspended in sterile MilliQ water to obtain a 10% dry mass solution and were inactivated by placing them at a temperature of 80°C for 1 minute. They were then centrifuged and then dried in an oven at 50°C for 2 hours and finally ground in a grinder. Results Figure 2 represents an example of the propagation of brewer's yeasts in a bioreactor for debittering. Growth was enabled by the nutrients initially present in the culture medium and by rigorous control of the physicochemical parameters (temperature, pH, agitation).The growth rate was controlled by the addition of the feed medium, whose carbon source (here, sucrose) is converted into biomass. 357 grams of S. cerevisae yeast, from an initial biomass of 125.4 g, were produced under these conditions, representing a multiplication of 2.8. The initial 5 grams of sucrose were consumed by the yeasts in the first 2 hours of the run. From 2 hours onwards, the feed medium was added. The addition rate was 0.15 g glucose equivalent / g. levure / h between 2 and 48h (final time) and allows a conversion efficiency of the carbon source into biomass of 0.21. Adding the carbon source gradually through the feed medium ensures a low quantity of carbon source (here, sucrose) instantaneously in the bioreactor and therefore avoids the accumulation of sucrose, which can lead to the accumulation of ethanol, a product of yeast metabolism, and therefore an inhibition of yeast propagation. 72.2 grams of ethanol were initially present in the culture medium, which comes from the beer medium inoculated with the yeasts. After 24h, all the ethanol has been consumed by the yeasts, which is also used as a carbon source for yeast propagation. Increasing the feed medium flow rate from 2 p.m. leads to the accumulation of ethanol in the bioreactor.EXAMPLE 16 Biomass propagation with glucose at 200L scale Spent Brewer's Yeast (SBY) was collected from a brewery. The initial transition medium is prepared in reverse osmosis water (Vi = 100L), ammonium sulfate (NH4)2SO4 (1000 g), potassium phosphate KH2PO4 (500 g), MgSO4 (160 g), yeast extract (100 g) and sucrose (500 g), Inositol (100 mg), Thiamine (800 mg), Riboflavin (200 mg), Calcium penthotenate (400 mg), ZnSO4 (100 mg), FeSO4 (100 mg), CaCl2 (1000 mg). The compounds sucrose, ammonium sulfate, potassium phosphate and MgSO4 were sterilized in the fermentation tank. The other compounds were filtered and then added to the medium. The physicochemical parameters of the bioreactor were set at pH=5, automatically regulated using a probe by a base solution (NaOH at 4 mol / L), a temperature of 30°C, an incoming air flow rate of 300 L / minute, and stirring at 300 RPM.The dissolved oxygen pressure is measured by a probe added to the bioreactor. The feed medium is prepared. 100 liters of a solution comprising sucrose at 200 g / L, (NH4)2SO4 at 25 g / L and KH2PO4 at 5 g / L is filtered. From 2 hours of run, (which happens from the contact of the yeasts with the medium until the moment when the debittered product is obtained) the feed is set up at a flow rate of 0.1 gglucose equivalent / g. levure / h up to 30h. Throughout the run, the increase in biomass was assessed by measuring the optical density (OD) at 600 nm using a spectrophotometer and by measuring the dry weight (washing, centrifugation, drying for 3h at 105°C then weighing a 10mL sample of the propagation medium). The concentration of ethanol and sucrose in the medium was assessed using an enzymatic ethanol assay kit marketed by Megazyme. Quantification of the contaminating bacterial flora (from SBY) was assessed by counting on Petri dishes (Plate Count Agar (PCA) + Cyclohexamine). After 30h of run, the yeasts were collected and centrifuged using a Lemitec decanter centrifuge (marketed by Lemitec). The yeasts were washed once by adding a volume of water equivalent to 2.5 times the weight of the pellet and then the yeasts were homogenized in a tank at 10°C.A second centrifugation using a Lemitec decanter centrifuge was carried out. The pellet was then resuspended in reverse osmosis water to obtain a 14% dry matter solution and the yeasts were inactivated using a tubular heat exchanger (sold by OMVE Lab & Pilot Equipment) to apply a thermal scale of 90°C for 5 seconds. They were then dried in a freeze dryer. ResultsFigure 7 represents an example of the propagation of brewer's yeasts in a bioreactor for debittering. Growth was enabled by the nutrients initially present in the culture medium and by rigorous control of the physicochemical parameters (temperature, pH, agitation). The growth rate was controlled by the addition of the feed medium whose carbon source (here, sucrose) is converted into biomass. 3900 grams of S. yeasts.cerevisae, from an initial biomass of 1296 g, were produced under these conditions, a multiplication of 3. The initial 500 grams of sucrose were consumed by the yeasts within the first 2 hours of the run. From 2 hours onwards, the feeding medium was added. The addition rate was 0.1 gglucose equivalent / g. levure / h between 2 and 30h (final time) and allows a conversion efficiency of the carbon source into biomass of 0.36. Adding the carbon source gradually through the feed medium ensures a low quantity of carbon source (here, sucrose) instantaneously in the bioreactor and therefore avoids the accumulation of sucrose, which can lead to the accumulation of ethanol, a product of yeast metabolism, and therefore an inhibition of yeast propagation. 918 grams of ethanol were initially present in the culture medium, which comes from the beer medium inoculated with the yeasts. After 12h, all the ethanol has been consumed by the yeasts, which is also used as a carbon source for yeast propagation. Increasing the feed medium flow rate from 16h leads to the accumulation of ethanol in the bioreactor.Alpha and beta acids were measured according to the method detailed in Example 4 at the end of the process: 0.117 µg of alpha acids / mg of yeast and 0.017 µg of beta acids / mg of yeast. EXAMPLE 17 Demonstration of the role of the oxidation of bitter molecules in the debittering process Spent brewers' yeasts (SBY for Spent Brewers Yeasts) were obtained by fermentation (5 days) of a malt extract wort (175 g / L for 25 total liters) supplemented with 0.12 mg / L of hop extract, inoculated with 2.5 g / L of Saccharomyces cerevisae US-05. After 6 days of fermentation, the yeasts were drawn off into a sterile flask from the bottom of the tank and were then inoculated into the 1L bioreactor at a concentration of 20 g / L. This process aims to replicate brewing fermentation and the yeast deposit of breweries.The initial transition medium is composed of milliQ water (400 mL), ammonium sulfate (NH4)2SO4 (10 g / L), potassium phosphate KH2PO4 (5 g / L), MgSO4 (0.8 g / L), yeast extract (1 g / L), glucose (5 g / L), inositol 10 mg / L, thiamine 58 mg / L), riboflavin (2 mg / L), calcium pantothenate (4 mg / L), ZnSO4 (4 mg / L), FeSO4 (10 mg / L), CaCl2 (100 mg / L). Each of these compounds was autoclaved separately beforehand to ensure sterility. The physicochemical parameters of the bioreactor were set at pH=5, automatically regulated using a probe with a base solution (KOH at 2 mol / L), a temperature of 30°C, agitation at 900 RPM and an air flow rate of 1.4L / h for the first 2 hours then 4L / h until 8 hours after the start of the run; 8.2 L / h between 8 hours and until the end of the run.Starting 2 h after the start of the run, an autoclaved feed medium solution composed of 200 g / L glucose, 5 g / L KH2PO4 and 25 g / L (NH4)2SO4 was added at a rate of 0.053 gglucose equivalent / g. levure / h. Throughout the run, the increase in biomass was assessed by measuring the dry weight (centrifugation, drying for 2 hours at 105°C, then by weighing a 5mL sample of the propagation medium). The ethanol concentration in the medium was assessed by HPLC (Thermo Scientific, Ultimate 3000) coupled with a Shodex refractometer and a Thermo Scientific ultraviolet detector at 210nm. An Aminex HPX-87H column (300x7.8mm, Bio-rad Laboratories SA) was used. The injection volume was 20 μL, and the column was maintained at 30°C. The samples were eluted isocratically with a solution of H2SO4 (4 mM) at a flow rate of 0.5mL / min for 30 minutes. The samples were first centrifuged at 4000g for 5min, diluted by half in H2SO4 (4mM) and filtered through 0.2 μm RC filters. Measurement of the concentration of bitter moleculesThe samples from these tests were analyzed to determine the concentration of bitter molecules.1 g of wet yeast was suspended in 5 mL of a 100:1 [v / v] mixture of methanol and phosphoric acid. Each sample was sonicated at room temperature for 30 min, centrifuged at 4000 g for 5 min and then filtered using a 0.2 μm polytetrafluoroethylene (PTFE) filter. The samples were then passed through an HPLC column (Fischer Scientific accucore™ aQ C18) using a gradient of acetonitrile and formic acid. A sensory evaluation of the samples was also carried out on a panel of 4 expert panelists. The quantification of the contaminating bacterial flora (originating from SBY) is assessed by counting on Petri dishes (PCA counting agar, marketed by Biokar Ⓡ). Results Figure 8 represents the progressive degradation of alpha acids adsorbed on the wall of used brewery yeasts.The feed medium flow rate was deliberately chosen to be low to maintain the basal metabolism of the yeasts while avoiding their propagation. Figure 8 shows that, despite the precautions taken, the biomass spread, leading to a final multiplicative factor of 1.38. The alpha acids adsorbed to the yeasts gradually decreased from 0.9 mg / g yeasts at T0 to 0.074 mg / g yeasts at T23 (Figure 8), due to the oxygenation of the medium leading to their oxidation. The sensory evaluation by the 4 expert panelists showed a bitterness score of 2 for this sample compared to a score of 5.5 for a sample in which used brewery yeasts were diluted by non-bitter US-05 yeasts (Lesaffre), thus demonstrating the essential role of oxygenation in the bioreactor in the elimination of perceived bitterness.Table 1 represents the dosage of bitter molecules (alpha acids and beta acids) on 2 batches of used brewery yeast (SBY, from an industrial brewery), before and after the process. Table 1. Dosage of bitter molecules on two batches of SBY before and after the process

Claims

CLAIMS 1. Use of a transition medium and a feed medium for implementing a process for debittering a brewing yeast resulting from brewing fermentation, notamment choisie parmi : Saccharomyces cerevisiae et Saccharomyces pastorianus, dans laquelle : ▪ ledit milieu de transition est un milieu aqueux de pH compris de 3 à 10, en particulier de 4 à 7 comprenant : − de 0 à 50 g / L, en particulier de 0 à 30 g / L, et plus particulièrement de 0 à 10 g / L, d’un sel d’ammonium choisi parmi : (NH4)2HPO4, (NH4)2SO4 et their mixture, or urea, corn solubles, protamylasse, − de 0 à 10 g / L, en particulier de 0 à 5 g / L, d’un sel de potassium choisi parmi : KH2PO4, K2HPO4 et leur mélange, − de 0 à 5 g / L, en particulier de 0 à 2 g / L, et plus particulièrement de 0 à 1 g / L, d’un sel de magnésium notamment MgSO4, − de 0 à 30 gglucose équivalent / L, en particulier de 0 à 5 gglucose équivalent / L, d’une source de carbone choisie parmi : du glucose, du saccharose, dumaltose, maltotriose, fructose, mannose, galactose, raffinose, trehalose, glycerol, beet molasses, onion crop residues, beer production waste consisting of or comprising the supernatant from the sedimentation of a fermented and drawn-off brewing yeast, brewer's grains, potato residue, bread production waste, dates, cane molasses, milling by-products, food industry by-products, and mixtures thereof, said carbon source optionally being enzymatically treated, in particular by an α-amylase or an amyloglucosidase, and − de 0 à 15 g / L, en particulier de 0 à 1 g / L, d’extrait de microorganisme inactivé ; ▪ ledit milieu d’alimentation est un milieu aqueux de pH compris de 3 à 10, en particulier de 4 à 7 comprenant : − de 0 à 50 g / L, en particulier de 0 à 30 g / L, et plus particulièrement de 0 à 10 g / L, d’un sel d’ammonium choisi parmi : (NH4)2HPO4, (NH4)2SO4 et their mixture, or urea, corn solubles, protamylasse, − de 0 à 10 g / L, en particulier de 0 à 5 g / L, d’un sel de potassium choisi parmi : KH2PO4, K2HPO4 et leur mélange, − de 0 à 5 g / L, en particulier de 0 à 2 g / L, et plus particulièrement de 0 à 1 g / L of a magnesium salt, in particular MgSO4, − de 50 à 500 gglucose équivalent / L, en particulier glucose équivalent e from 175 to 225 g glucose é de 150 à 250 g / L (preferably quivalent / L), from a carbon source c hoisie parmi : du glucose, du saccharose, du maltose, du maltotriose, fructose, mannose, galactose, raffinose, trehalose, glycerol, beet molasses, onion crop residues, es écarts de production de bière constitués de ou comprenant le supernatant from the sedimentation of fermented and drawn-off brewing yeast, brewery spent grain, potato residue, bread production waste, dates, cane molasses, milling by-products, food industry by-products, and mixtures thereof, ethanol, preferably glucose, sucrose, maltose, maltotriose, ethanol, beet molasses, bread production waste, potato residue or beer production waste consisting of or comprising the supernatant resulting from the sedimentation of a fermented and drawn-off brewing yeast, and mixtures thereof, said carbon source optionally being enzymatically treated, in particular by an α-amylase or an amyloglucosidase, and − de 0 à 15 g / L, en particulier de 0 à 1 g / L, d’extrait de microorganisme inactivé ; and wherein said transition medium is used upstream of said feed medium, said feed medium supplementing said transition medium, adite désamérisation de ladite levure étant : ▪ une réduction d’au moins 70% de la teneur en acides alpha, lesdits acides alpha étant notamment la cohumulone, l’adhumulone et l’humulone ; and / or ▪ une réduction d’au moins 50% de la teneur en acides bêta, lesdits acides bêta being in particular lupulone, adlupulone and colupulone, said reductions being measured relative to said brewing yeast resulting from brewing fermentation.

2. Use of a transition medium and a feed medium for the preparation of a debittered yeast powder from a brewing yeast resulting from fermentationbrassicole, notamment choisie parmi : Saccharomyces cerevisiae et Saccharomyces pastorianus, dans laquelle : ▪ ledit milieu de transition est un milieu aqueux de pH compris de 3 à 10, en particulier de 4 à 7 (et plus particulièrement 5), comprenant : − de 0 à 50 g / L, en particulier de 0 à 30 g / L, et plus particulièrement de 0 à 10 g / L, d’un sel d’ammonium choisi parmi : (NH4)2HPO4, (NH4)2SO4 et their mixture, or urea, corn solubles, protamylasse, − de 0 à 10 g / L, en particulier de 0 à 5 g / L, d’un sel de potassium choisi parmi : KH2PO4, K2HPO4 et leur mélange, − de 0 à 5 g / L, en particulier de 0 à 2 g / L, et plus particulièrement de 0 à 1 g / L of a magnesium salt, in particular MgSO4, − de 0 à 30 gglucose équivalent / L, en particulier de 0 à 5 gglucose équivalent / L, d’une source de carbone choisie parmi : du glucose, du saccharose, du maltose, maltotriose, fructose, mannose, galactose, raffinose, trehalose, glycerol, beet molasses, onion crop residues, beer production waste consisting of or comprising the supernatant from the sedimentation of a fermented and drawn-off brewing yeast, brewer's grains, potato residue, bread production waste, dates, cane molasses, milling by-products, food industry by-products, and mixtures thereof, said carbon source optionally being enzymatically treated, in particular by an α-amylase or an amyloglucosidase, and − de 0 à 15 g / L, en particulier de 0 à 1 g / L, d’extrait de microorganisme inactivé ; ▪ ledit milieu d’alimentation est un milieu aqueux de pH compris de 3 à 10, en particulier de 4 à 7 (et plus particulièrement de 5 à 6), comprenant : − de 0 à 50 g / L, en particulier de 0 à 30 g / L, et plus particulièrement de 0 à 10 g / L, d’un sel d’ammonium choisi parmi : (NH4)2HPO4, (NH4)2SO4 ettheir mixture, or urea, corn solubles, protamylasse, − de 0 à 10 g / L, en particulier de 0 à 5 g / L, d’un sel de potassium choisi parmi : KH2PO4, K2HPO4 et leur mélange, − de 0 à 5 g / L, de 0 à 2 g / L, et plus particulièrement de 0 à 1 g / L, d’un sel magnesium, especially MgSO4, − de 50 à 500 gglucose équivalent / L, en particuli glucose équivalent weight of 175 to 225 g gluco er de 150 à 250 g / L, preferably se équivalent / L, of a carbon source c hoisie parmi : du glucose, du saccharose, du maltose, du maltotriose,fructose, mannose, galactose, raffinose, trehalose, glycerol, beet molasses, onion crop residues, beer production deviations consisting of or comprising the supernatant resulting from the sedimentation of a fermented and drawn-off brewing yeast, brewer's grains, potato residue, bread production deviations, dates, cane molasses, milling by-products, food industry by-products, ethanol and mixtures thereof, preferably glucose, sucrose, maltose, maltotriose, ethanol, beet molasses, bread production deviations, potato residue or beer production deviations consisting of or comprising the supernatant resulting from the sedimentation of a fermented and drawn-off brewing yeast, and mixtures thereof carbon source being possibly treated enzymatically, in particular by an α-amylase or an a myloglucosidase ou une protéase, et − de 0 à 15 g / L, en particulier de 0 à 1 g / L, d’extrait de microorganismeinactivé ; ladite poudre de levures désamérisées comprenant : ▪ de 0,002 à 0,400 mg d’acides alpha / g de levures désamérisées, de préférence from 0.050 to 0.200 mg of alpha acids / g of debittered yeasts, said alpha acids lpha étant notamment la cohumulone, l’adhumulone et l’humulone ; and / or, ▪ de 0,001 à 0,300 mg d’acides bêta / g de levures désamérisées, de préférence from 0.001 to 0.010 mg of beta acids / g of debittered yeasts, said beta acids being in particular lupulone, adlupulone and colupulone. et ladite poudre de levures désamérisées a une amertume égale à l’amertume de 0 à 0.12 mg of isohumulones / g of dry yeast, in particular from 0 to 0.06 mg of isohumulones / g of dry yeast, in particular, said transition medium comprising a selected carbon source parmi : des écarts de production de bière constitués de ou comprenant le surnageant from the sedimentation of a fermented and drawn-off brewing yeast, potato residue, glucose, sucrose, maltose, maltotriose, beet molasses, bread production waste and mixtures thereof, preferably beer production waste consisting of or comprising the supernatant from the sedimentation of a fermented and drawn-off brewing yeast, said carbon source optionally being enzymatically treated.

3. Use according to any one of claims 1 to 2, wherein said medium de transition comprend en outre : ▪ des sels minéraux choisi parmi : du ZnSO4 à raison de 0 à 20 mg / L, notamment from 3 to 10 mg / L, CaCl2 at a rate of 0 to 1 g / L, in particular from 50 to 200 mg / L, FeSO4 at a rate of 0 to 20 mg / L, in particular from 3 to 10 mg / L, H3BO3, C uSO4, du Na2MoO4, du MnCl2, du CoCl2, du KCI et leurs mélanges ; et / ou ▪ de l’EDTA ; et / ou ▪ des vitamines choisies parmi : la vitamine B1 (thiamine) à raison de de 0 à 20mg / L, including 6 to 10mg / L, vitamin B2 (riboflavin) at a rate of 0 to 20mg / L, including 1 to 5mg / L, vitamin B3 (niacin) at a rate of 0 to 10mg / L, including 0 to 3mg / L, vitamin B5 (calcium pantothenate) at a rate of 0 to 20mg / L, including 2 to 6mg / L, vitamin B6 (pyridoxine) at a rate of 0 to 20mg / L, including 2 to 6mg / L), vitamin B7 (inositol) at a rate of 0 to 20mg / L, including 8 to 15mg / L), vitamin B8 (biotin) at a rate of 0 to 2mg / L, vitamin B10 (para-aminobenzoic acid) at a rate of 0 à 2mg / L et leurs mélanges ; et / ou ▪ de la peptone à raison de 0 à 20 g / L ; et / ou ▪ du Yeast Nitrogen Base (YNB), ▪ des tensioactifs à raison de 0 g / L à 1 g / L.

4. Use according to any one of claims 1 to 3, wherein said medium d’alimentation comprend une source de carbone choisie parmi : des écarts de production debeer consisting of or comprising the supernatant from the sedimentation of a fermented and drawn-off brewing yeast, potato residue, glucose, sucrose, maltose, maltotriose, ethanol, beet molasses, bread production waste and mixtures thereof, preferably beer production waste consisting of or comprising the supernatant from the sedimentation of a fermented and drawn-off brewing yeast, said carbon source optionally being enzymatically treated, e t éventuellement dans laquelle ledit milieu d’alimentation comprend en outre : ▪ des sels minéraux choisi parmi : du ZnSO4, du CaCl2, du FeSO4, du H3BO3, du CuSO4, du Na2MoO4, du MnCl2, du CoCl2, du KCI et leurs mélanges ; et / ou ▪ de l’EDTA ; et / ou ▪ des vitamines choisies parmi : la vitamine B1 (thiamine), la vitamine B2 (riboflavin), vitamin B3, vitamin B5 (calcium pantothenate), vitamin B6, vitamin B7 (inositol), vitamin B8 (biotin), vitamin B10 and their m élanges ; et / ou ▪ de la peptone ; et / ou ▪ du Yeast Nitrogen Base (YNB).

5. Poudre de levures désamérisées comprenant : ▪ de 0,002 à 0,400 mg d’acides alpha / g de levures désamérisées, de préférence from 0.050 to 0.200 mg of alpha acids / g of debittered yeasts, said alpha acids lpha étant notamment la cohumulone, l’adhumulone et l’humulone ; ▪ de 0,001 à 0,300 mg d’acides bêta / g de levures désamérisées, de préférencefrom 0.001 to 0.010 mg of beta acids / g of debittered yeasts, said b acids êta étant notamment la lupulone, l’adlupulone et la colupulone ; et said debittered yeast powder having a bitterness equal to the bitterness of 0.0625 to 0.250 mg of isohumulones / g of dry yeast, in particular equal to 0.125 mg of isohumulones / g of dry yeast, said debittered yeast powder having a dry matter content of 90 to 100%, in particular 92 to 98%, and said debittered yeast powder being in particular in ground form, said ground debittered yeast powder having in particular a median particle size of 5 to 200 µm, in particular 6 to 80 µm, in particular 8 to 30 µm.

6. Debittered yeast powder according to claim 5, said debittered yeast powder having a dispersibility of 60 to 100%, in particular 75 to 95%, and / or, ▪ une capacité de rétention d’eau comprise de 2,0 à 4,0 g d’eau / g de ladite debittered yeast powder, in particular 3.0 to 3.5 g of water / g of said powder oudre de levures désamérisées ; et ▪ une activité de l’eau comprise de 0,30 à 0,62, and / or, ▪ une activité émulsifiante comprise de 40 à 80 g / m², en particulier de 55 à 65g / m² ; et ▪ une stabilité émulsifiante comprise de 75 à 100 minutes, en particulier de 85 à 95 minutes, and / or, having a minimum gelling concentration of 15 to 30%, in particular 23 to 28%, said minimum gelling concentration being expressed as a mass percentage, and / or, having a protein concentration of 25 to 60%, in particular 45 to 55%.

7. Process for the manufacture of a powder of debittered yeasts, collected, optionally washed, inactivated, dried and optionally ground, said process comprenant au moins les étapes de : a. désamérisation comprenant au moins les étapes : i) de mise en culture d’une levure brassicole issue de la fermentation brassicole, notamment choisie parmi : Saccharomyces cerevisiae et Saccharomyces pastorianus inoculée, à raison de 10 à 100 g / L dans un bioreactor, said cultivation being carried out in a medium of t ransition dans des conditions : − d'agitation comprise de 25 à 1000 rpm, et − de températures comprise de 4 à 37 °C, en particulier de 7 à 32°C, ledit milieu de transition comprenant : − de 0 à 50 g / L, d’un sel d’ammonium ou d’urée, des solubles de corn, protamylasse, − de 0 à 10 g / L d’un sel de potassium − de 0 à 5 g / L d’un sel de magnésium notamment MgSO4, − de 0 à 30 gglucose équivalent / L d’une source de carbone choisie parmi : glucose, sucrose, maltose, maltotriose, fructose, mannose, galactose, raffinose, trehalose, glycerol, beet molasses, onion crop residues, beer production waste consisting of or c omprenant le surnageant issu de la sédimentation d’une levurefermented and drawn brewery waste, brewery spent grain, potato residue, bread production waste, dates, cane molasses, milling by-products, agri-food industry by-products, and mixtures thereof, said carbon source possibly being enzymatically treated, in particular by an α-amylase or an amyloglucosidase, and − de 0 à 15 g / L, d’extrait de microorganisme inactivé, and whose pH is regulated in real time and is between 3 and 10, and ii) de fermentation discontinue alimentée non soutirée (fed-batch) de ladite brewing yeast cultured, after exhaustion of the carbon source of said transition medium, to obtain debittered yeasts, said fed-batch being carried out using a medium ’alimentation dans des conditions : − d'agitation dudit milieu de transition comprise de 100 à 1000 rpm, and − de température comprise de 20 à 35°C, said feed medium being added at a flow rate, in particular at a constant flow rate, of from 0.01 to 0.50 g glucose équivalent / g of biomass / h for u ne durée comprise de 6 à 72h, ledit milieu d’alimentation comprenant : − de 0 à 50 g / L d’un sel d’ammonium ou d’urée, des solubles de corn, protamylasse − de 0 à 10 g / L d’un sel de potassium, − de 0 à 5 g / L d’un sel de magnésium notamment MgSO4, − de 50 à 500 gglucose équivalent / L, d’une source de carbone choisie parmi : du glucose, du saccharose, du maltose, du fructose, dumannose, galactose, raffinose, trehalose, glycerol, maltotriose, ethanol, beet molasses, onion crop residues, beer production waste consisting of or comprising the supernatant from the sedimentation of a fermented and drawn-off brewing yeast, brewer's grains, potato residue, bread production waste, dates, cane molasses, milling by-products, food industry by-products, and mixtures thereof, said carbon source optionally being enzymatically treated, and − de 0 à 15 g / L d’extrait de microorganisme inactivé, and whose pH is regulated in real time and is between 3 and 10, and possibly, iii) a continuous withdrawal step or supplementation with a supplemented medium containing brewing yeast from continuous brewing fermentation, and continuous racking, p our obtenir des levures désamérisées ; b. collecte desdites levures désamérisées par filtration ou centrifugation ou une décantation simple pour obtenir des levures désamérisées et collectées ; c. optionnellement lavage desdites levures désamérisées et collectées pour obtenir des levures désamérisées, collectées et optionnellement lavées ; d. séchage desdites levures désamérisées, collectées, optionnellement lavées,to obtain a powder of debittered, collected, optionally washed, and dried yeasts having a dry matter content of 90 to 100%, said drying being carried out for a period of 0.5 to 180 min, at a temperature of 40 to 150°C; and optionally a step of inactivating said debittered yeasts obtained at the end of step a, said debittered and collected yeasts obtained at the end of step b, or said debittered, collected and optionally washed yeasts obtained at the end of step c, to obtain debittered and inactivated yeasts, debittered collected and inactivated yeasts or debittered, collected, inactivated and optionally washed yeasts, said inactivation being carried out in an aqueous medium comprising from 1 to 30% of dry mass, for a duration of from 0.05 seconds to 30 min, in particular from 0.05 seconds to 10 min, at a temperature of from 50 to 9 5°C ou de 50 à 80°C ; etoptionally grinding said debittered, collected, optionally washed, inactivated and dried yeast powder to obtain a debittered, collected, optionally washed, inactivated, dried and optionally ground yeast powder having a median particle size of 5 to 25 µm, said debittered, collected, optionally washed, inactivated, dried yeast powder et éventuellement broyée comprend : ▪ de 0,002 à 0,400 mg d’acides alpha / g de levures désamérisées, lesdits acides alpha étant notamment la cohumulone, l’adhumulone et l’humulone ; and / or, ▪ de 0,001 à 0,300 mg d’acides bêta / g de levures désamérisées, lesdits acides bêta being in particular lupulone, adlupulone and colupulone.

8. Method according to claim 7, in which said step a.ii) of culturing is carried out under pO2 conditions of from 0 to 100%, in particular from 20 to 60% and more particularly from 35 to 45%, and / or, d ans lequel ladite étape a.iii) de fed-batch est réalisée dans des conditions de pO2 comprised from 0 to 100%, in particular from 20 to 60% and more particularly from 35 to 45%, and / or, in which said transition medium is optionally enzymatically treated.

9. Method according to any one of claims 7 or 8, said method further comprising and upstream of said step a. ε) of inoculation or ai) of culturing at least, a step I of drawing off a brewing yeast during the brewing fermentation, in particular after the primary fermentation, to obtain a brewing yeast s outirée ; et éventuellement au moins les étapes de : II de sédimentation de ladite levure brassicole soutirée pour obtenir une levure brassicole soutirée et sédimentée, et un surnageant ; et / ou III de concentration de ladite levure brassicole soutirée et sédimentée, notamment by removing said supernatant, to obtain a drawn-off brewing yeast, édimentée et concentrée de 10 à 25% en matière sèche, ledit pourcentage en dry matter being expressed in mass concentration.

10. Method according to any one of claims 7 to 9, in which said brewing yeast resulting from brewing fermentation is a brewing yeast drawn off at the end of primary fermentation having in particular a viability of 60 to 100%, preferably 85 to 95%.

11. Method according to any one of claims 7 to 10, in which said yeast brassicole issue de la fermentation brassicole comprend : ▪ de 0,3 à 15 mg ou de 0,3 à 7 mg d’acides alpha / g de levures désamérisées, enin particular from 0.5 to 1.5 mg of alpha acids / g of debittered yeasts, said cides alpha étant notamment la cohumulone, l’adhumulone et l’humulone ; ▪ de 0 à 15 mg ou de 0,2 à 4 mg d’acides bêta / g de levures désamérisées, en in particular from 0.3 to 0.6 mg of beta acids / g of debittered yeasts, said beta acids being in particular lupulone, adlupulone and colupulone.

12. Debittered yeast powder capable of being obtained by the manufacturing process according to any one of claims 7 to 11

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