PROCESS FOR DEBITTERIZING BREWING YEASTS AND DEBITTERIZED 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 brewing yeast resulting from brewing fermentation. (no figures)

Description

Title of the invention: PROCESS FOR DEBITTERIZING BREWING YEASTS AND DEBITTERIZED PRODUCTS OBTAINED Technical field

[0001] The present invention relates to a process for debittering brewing yeasts from brewing fermentation and the debittered yeasts obtained. State of the art

[0002] 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 uses of the industry (production of steam, cold, agricultural raw materials for example). In addition, a general awareness of the environmental impact of food and the production of animal proteins is leading to the development of alternative diets.

[0003] During brewing fermentation, a surplus of brewer's 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 or 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.

[0004] These yeasts are linked to bitter molecules related to the brewing process. The main molecules identified so far are as follows:

[0005] • Alpha acids: humulone, cohumulone, adhumulone.

[0006] • Beta Acids: Lupulone, colupulone, adlupulone.

[0007] * Isoalpha acids: Isohumulones, isocohumulones, isoadhumulones

[0008] [Chem.l] Titles: £-3loha Iterarial chain R: cehiinssîan® iS0«<5JwW*« ^SfrsKfJtss Ss^wanSsM»

[0009]

[0010]

[0011]

[0012]

[0013]

[0014] These compounds bind primarily to yeast cell walls. The concentration of these compounds typically depends on their cell wall affinity 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 matter 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 nutritionally relevant compounds by removing proteins and other materials present in brewer's 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, namely the lack of ease of filtration of the lysates and the simultaneous adsorption removal of food compounds of interest. Also, processes using alkaline suspensions generate significant quantities of water and alkaline solution that are harmful to the environment. The invention aims to address the above problem and to enable the use of brewing yeasts free from bitter molecules in the food industry. One aspect of the present invention is the use of a brewing yeast derived from brewing fermentation in carrying out a debittering process. Another aspect of the present invention is the use of co-products from the agri-food industry as a carbon source in a debittering process.

[0015] Another aspect of the present invention is a method of debittering brewing yeast.

[0016] Another aspect of the present invention is the use of a transition medium and a feed medium to enable the propagation of the biomass of a brewing yeast and to obtain a debittered brewing yeast.

[0017] Another aspect of the present invention is the use of a brewing yeast for the preparation of debittered yeast powder.

[0018] Another aspect of the present invention is to provide a method of manufacturing a debittered yeast powder.

[0019] Another aspect of the present invention is a debittered brewing yeast powder.

[0020] Another aspect of the invention is the debittering of brewing yeasts without major chemical releases and in a minimal processing approach.

[0021] Another aspect of the invention is the adjustment of the conditions of the propagation medium in order to maximize the degradation of the bitter compounds. Statement of the invention

[0022] The present 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, in particular chosen from: Sac-charomyces cerevisiae and Saccharomyces pastorius, in which:

[0023] □ said transition medium is an aqueous medium with a pH of between 3 and 10, in par particular from 4 to 7, including: • from 0 to 50 g / L, in particular 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 1 g / L, of a magnesium salt MgSO4, • from 0 to 30 µg / L, in particular from 0 to 5 µg / L, from a source of carbon selected 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, brewery spent grain, potato residue, bread production waste, dates, cane molasses, milling by-products, food industry by-products, and mixtures thereof,

[0024] 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;

[0025] □ said feed medium is an aqueous medium with a pH of from 3 to 10, in particular from 4 to 7, including: • from 0 to 50 g / L, in particular 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 1 g / L, of a magnesium salt MgSO4, • from 50 to 500 gg^ose equivalents / L, in particular from 150 to 250 gg^ose equivalents / L (of preferably 175 to 225 gg^ose equivalents / 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, 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 variance, potato residue or beer production variance consisting of or including the supernatant from the sedimentation of fermented and drawn-off brewing yeast,and their mixtures, ,

[0026] 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;

[0027] and wherein said transition medium is used upstream of said feed medium, said feed medium supplementing said transition medium,

[0028] said debittering of said yeast being: • a reduction of at least 70% in the content of alpha acids, said alpha acids being in particular cohumulone, adhumulone and humulone;

[0029] and / or, • a reduction of at least 50% in the content of beta acids, said beta acids being in particular lupulone, adlupulone and colupulone.

[0030] 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 with the aim of maintaining the ethanol resulting from the fermentation at a rate lower than 20g / L, because an ethanol concentration higher than 20g / L slows down the propagation of the biomass and therefore the debittering process.

[0031] 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 pastorius.

[0032] By “derived from brewing fermentation” we mean that the yeast is derived from the fermentation of beer.

[0033] The brewing yeast from brewing fermentation is recovered, possibly by centrifugation and by filtration of the brewery tank bottoms. It allows the tank bottoms to be separated into three different fractions:

[0034] * Brewing residues (solid particles of hops, barley malt)

[0035] • Brewing yeasts

[0036] • A residue of wort during fermentation / beer

[0037] The filtration step is optional when the brewing residue content is less than 40% of the dry matter of the tank bottoms in which the fermentation took place.

[0038] 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 the increase in brewing yeast biomass makes it possible to drastically reduce the bitter molecule content.

[0039] The invention involves a transition medium and a feed medium.

[0040] 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. The following are understood to mean: 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.

[0041] By "ammonium salt" is meant an 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". This means: 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.

[0042] 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 “0 to 10 g / L” means: 0 to 1 g / L, 1 to 2 g / L, 2 to 3 g / L, 3 to 4 g / L, 4 to 5 g / L, 5 to 6 g / L, 6 to 7 g / L, 7 to 8 g / L, 8 to 9 g / L, 9 to 10 g / L.

[0043] The expression "magnesium salt" designates an ionic compound of cations and anions, in which at least one cation is an Mg2+ cation. This is present in an amount of "from 0 to 5 g / L", meaning: from 0 to 0.5 g / L, from 0.5 to 1 g / L, from 1 to 1.5 g / L, from 1.5 to 2 g / L, from 2 to 2.5 g / L, from 2.5 to 3 g / L, from 3 to 3.5 g / L, from 3.5 to 4 g / L, from 4 to 4.5 g / L, from 4.5 to 5 g / L.

[0044] By "carbon source" is meant 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 from the sedimentation of a fermented and drawn-off brewing yeast, brewery spent grain, potato residue hydrolyzed by an α-amylase, bread production waste, dates, cane molasses, milling by-products, food industry by-products, and mixtures thereof.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.

[0045] 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.

[0046] By "inactivated microorganism extract" is meant an extract of lysed microorganism which contributes to the propagation of the biomass by providing nutrients to the brewing yeast, and which does not propagate alone. This is present at a rate of "from 0 to 15 g / L", meaning: from 0 to 3 g / L, from 3 to 6 g / L, from 6 to 9 g / L, from 9 to 12 g / L and from 12 to 15 g / L.

[0047] The "feeding medium" means a medium containing the microelements necessary for the propagation of a microorganism, a quantity of carbon compounds which are a source of carbon and energy higher than that of the transition medium and possibly an extract of inactivated microorganism. The 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. The following are understood to mean: 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.

[0048] 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 α-amylase, beer production deviations consisting of or comprising the supernatant from the sedimentation of a fermented and drawn-off brewing yeast, brewer's grains, potato residue hydrolyzed by 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 from the sedimentation of a fermented and drawn-off brewing yeast, and their mixtures.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, 450 to 500 g / L.

[0049] The propagation of the biomass occurs in the medium formed by the transition medium to which the feed medium is gradually added.

[0050] 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.

[0051] 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.

[0052] The expression "gg^oseequivalent / 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.

[0053] By "debittering" is meant the reduction of the content of bitter molecules below the level of the perception threshold by a human being for the yeasts to be used for the manufacture of food products. Bitter molecules can be of natural or synthetic origin and are perceived by the taste receptors in the taste buds of the tongue by taste receptors (type 2 receptors or T2R).

[0054] The invention makes it possible to reduce the content of bitter molecules of, in particular, co-humolone, humolone, adhumolone, colupulone, lupulone, adlupulone, isocohumolone, isohumulone, isoadhumulone, xanthohumol, hulupone, humulinone, and humulinic acid.

[0055] The bitter molecules adsorbed on the walls of brewing yeasts come from lupulin and are: Alpha acids, with the following structures:

[0056] [Chem.2]

[0057]

[0058]

[0059]

[0060] [Chem. 3]

[0061] [Chem. 4] Beta acids, with the following structures:

[0063]

[0064]

[0062] [Chem. 6]

[0065]

[0066] lupulone [Chem. 7]

[0067]

[0068]

[0069]

[0070] 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 solubles” refers to corn steeping water, concentrated or not, produced during the starch process.

[0071] The expression “protamylasse” designates a concentrate obtained by evaporation of the vegetation water from potatoes during the starch process.

[0072] In particular, the carbon source may be a co-product or by-product of the agri-food industry.

[0073] The expression “beet molasses” designates a non-crystallizable syrupy liquid, a residue from the crystallization and refining of beet sugar.

[0074] The expression “onion crop residues” means the peelings or any other unused part of the onion.

[0075] The expression “beer production deviations” designates all fractions of brewing production not packaged or marketed.

[0076] By "brewery spent grain" is meant the residue of cooked barley which remains in the vat after mashing and before boiling the wort.

[0077] The expression “potato residue” means peelings, any other unvalued part of the potato or whole downgraded potatoes.

[0078] The expression “bread production deviation” refers to non-compliant kneaders and finished products obtained during bakery production.

[0079] The expression “date” here designates a fruit of Phoenix dactylifera.

[0080] The expression “cane molasses” designates a non-crystallizable syrupy liquid, residue from the crystallization and refining of sugar from sugar cane.

[0081] The expression “brans and remoulages” designates co-products of semolina or milling which may be derived from durum wheat, soft wheat, corn or spelt.

[0082] The expression “co-products of the agri-food industry” here designates a material, intentional and unavoidable, created during the same manufacturing process and at the same time as the main product obtained within the framework of an agri-food manufacturing process.

[0083] The expression “internal wash water” designates the wash water produced during the production of debittered beer yeasts.

[0084] The expression “wash water from the food industry” refers to wash water from other food production.

[0085] 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.

[0086] 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.

[0087] In a particular embodiment, the invention relates to the use of a medium transition medium and a feed medium for implementing a process 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.

[0088] 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.

[0089] The term "purines" refers to aromatic heterocycles composed of carbon and nitrogen. Purines include adenine and guanine, which are involved in the formation of DNA and RNA.

[0090] 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.

[0091] 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 isoalpha acid content, said iso-alpha acids being in particular isocohumolone, isohumolone and isoadhumulone.

[0092] 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: Saccharomyces cerevisiae and Saccharomyces pastorius, in which:

[0093] □ said transition medium is an aqueous medium with a pH of between 3 and 10, in par particular from 4 to 7 (and more particularly from 5), including: • from 0 to 50 g / L, in particular 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 1 g / L, of a magnesium salt MgSO4, • from 0 to 30 ggi^e equivalents / L, in particular from 0 to 5 gg^e equivalents / L, from a source of carbon selected 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 fermented and drawn-off brewing yeast, brewery spent grain, potato residue, bread production deviations, dates, cane molasses, milling by-products, food industry by-products, and mixtures thereof,

[0094] 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;

[0095] □ said feed medium is an aqueous medium with a pH of between 3 and 10, in par particular from 4 to 7 (and more particularly from 5), including: • from 0 to 50 g / L, in particular 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 1 g / L, of a magnesium salt MgSO4, • from 50 to 500 g glucose equivalent / L, in particular from 150 to 250 g glucose equivalent / L, preferably from 175 to 225 gg^e equivalents / 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, brewery spent grain, potato residue, bread production waste, dates, cane molasses, milling co-products, food industry co-products, ethanol and mixtures thereof, preferably glucose, sucrose, maltose, maltotriose, ethanol, beet molasses, production waste bread, potato residue or beer production waste consisting of or including the supernatant from the sedimentation of fermented and drawn-off brewing yeast,and their mixtures,

[0096] 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;

[0097] 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;

[0098] 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,

[0099] 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.

[0100] The expression "debittered yeast powder" designates a solid composition formed from yeasts which have been subjected to the debittering process. It is the yeasts which are debittered.

[0101] By “dry yeast” is meant a yeast having a water content of at least 0% and at most 10%, the percentage being expressed by mass relative to the total mass of the yeast.

[0102] Beyond a bitterness value greater than 0.250 mg of isohumulones / g of dry yeasts, the yeasts cannot be used as an ingredient in the food industry without the introduction of bitter taste to the final product.

[0103] The use of a transition medium and a feed medium for implementing a process for debittering a brewing yeast resulting from brewing fermentation according to the invention may involve an enzymatic treatment of the carbon source of the transition medium and / or the feed medium.

[0104] 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.

[0105] 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

[0106] said carbon source being optionally treated enzymatically.

[0107] In the transition medium, the carbon source may or may not be treated enzymatically.

[0108] The carbon source is not enzymatically treated when the carbon source is directly assimilable by the yeast.

[0109] 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, brewery spent grain, beer production waste, certain agri-food co-products or the carbon source is not enzymatically treated.

[0110] 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.

[0111] By way of example and in a non-limiting manner, when the carbon source of the transition medium is potato residues, brewery spent grain, 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.

[0112] In a particular embodiment, the invention relates to the use as defined above 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 pastorius, in which:

[0113] □ said transition medium is an aqueous medium with a pH of between 3 and 10, in par particular from 4 to 7 (and more particularly 5), including: • from 0 to 50 g / L, in particular 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 1 g / L, of a magnesium salt MgSO4, • from 0 to 30 gg^ose equivalents / L, in particular from 0 to 5 gg^ose equivalents / L, from a source of carbon selected 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, spent grain brewery waste, potato residue, bread production waste, dates, cane molasses, milling by-products, food industry by-products, and their mixtures,

[0114] 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;

[0115] □ said feed medium is an aqueous medium with a pH of between 3 and 10, in par particular from 4 to 7 (and more particularly from 5), including: • from 0 to 50 g / L, in particular 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 1 g / L, of a magnesium salt MgSO4, • from 50 to 500 g glucose equivalent / L, in particular from 150 to 250 g glucose equivalent / L, preferably from 175 to 225 gg^e equivalents / 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, brewery spent grain, potato residue, bread production waste, dates, cane molasses, milling by-products, food industry by-products, ethanol and mixtures thereof, preferably glucose, sucrose, maltose, maltotriose, ethanol, beet molasses, production of bread, potato residue or beer production waste consisting of or comprising the supernatant resulting from the sedimentation of fermented and drawn-off brewing yeast,and their mixtures,

[0116] 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;

[0117] 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;

[0118] 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.

[0119] 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,

[0120] in particular, said transition medium comprising 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,

[0121] said carbon source being optionally treated enzymatically.

[0122] 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,

[0123] said carbon source being treated enzymatically, in particular by an α-amylase or an amyloglucosidase.

[0124] The role of α-amylase is to break the α(1 —>4)glycosidic bonds within the amylose and amylopectin chains to yield maltose molecules.

[0125] The role of amyloglucosidase is to catalyze the hydrolysis of unsubstituted glucose units in glycogen linked by α(1 —>6) bonds to α(1 —>4)glucose chains and to generate glucose as a carbon source.

[0126] 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,

[0127] said carbon source being treated enzymatically, in particular by an α-amylase and an amyloglucosidase.

[0128] 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,

[0129] said carbon source not being enzymatically treated.

[0130] 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 (para-aminobenzoic acid) at a rate of 0 to 2 mg / L and their mixtures; and / or • peptone at a rate of 0 to 20 g / L; and / or • Yeast Nitrogen Base (YNB).

[0131] 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.

[0132] 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 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 waste consisting of or comprising the supernatant from the sedimentation of a fermented and drawn-off brewing yeast,

[0133] said carbon source being optionally enzymatically treated.

[0134] In the feed medium, the carbon source may or may not be enzymatically treated.

[0135] The carbon source is not enzymatically treated when the carbon source is directly assimilable by the yeast.

[0136] 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.

[0137] 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 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 waste consisting of or comprising the supernatant from the sedimentation of a fermented and drawn-off brewing yeast,

[0138] said carbon source being enzymatically treated, in particular by an α-amylase or an amyloglucosidase.

[0139] 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 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 waste consisting of or comprising the supernatant from the sedimentation of a fermented and drawn-off brewing yeast,

[0140] said carbon source being optionally enzymatically treated, in particular by an α-amylase and an amyloglucosidase.

[0141] In a particular embodiment, the invention relates to the use as defined above, in which said supply medium comprises a source of carbon selected from: beer production deviations 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 deviations and mixtures thereof, preferably beer production deviations consisting of or comprising the supernatant from the sedimentation of a fermented and drawn-off brewing yeast,

[0142] said carbon source not being enzymatically treated.

[0143] In a particular embodiment, the invention relates to the use as defined above, in which 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).

[0144] 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,

[0145] said carbon source being optionally treated enzymatically.

[0146] and optionally 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).

[0147] Another object of the invention relates to the use of a transition medium and a feed medium for implementing a debittering process for preparing a debittered yeast powder from a brewing yeast resulting from brewing fermentation.

[0148] The invention also relates to the debittered yeast powder which can be obtained by using the transition and feeding media defined above.

[0149] 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 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;

[0150] 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,

[0151] said debittered yeast powder having a dry matter content of 90 to 100%, in particular 92 to 98%, and

[0152] said debittered yeast powder being in particular in ground form, said ground debittered yeast powder having in particular a median particle size of from 5 to 200 pm, in particular from 6 to 80 pm, in particular from 8 to 30 pm.

[0153] By "bitterness" we mean bitterness as one of the five primary tastes, namely: sweet, salty, bitter, sour and umami.

[0154] By "from 90 to 100%" is meant: from 90% to 91%, from 91% to 92%, from 92 to 93%, from 93 to 94%, from 94% to 95%, from 95% to 96%, from 96 to 97%, from 97 to 98%, from 98% to 99, from 99 to 100%.

[0155] The expression “median particle size” designates the sizes of the particles of the debittered yeast powder, and among which less than 50% of them are located in this size range.

[0156] By "from 5 to 200 pm" is meant: from 5 to 15 pm, from 15 to 25 pm, from 25 to 35 pm, from 35 to 45 pm, from 45 to 55 pm, from 55 to 65 pm, from 65 to 75 pm, from 75 to 85 pm, from 85 to 95 pm, from 95 to 105 pm, from 105 to 115 pm, from 115 to 125 pm, from 125 to 135 pm, from 135 to 145 pm, from 145 to 155 pm, from 155 to 165 pm, from 165 to 175 pm, from 175 to 185 pm, from 185 to 7:55 pm and 7:55 to 8:00 pm.

[0157] In a particular embodiment, the invention relates to a powder of debittered yeasts as defined above, further comprising 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,

[0158] 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.

[0159] The term "dispersibility" refers to the ability of the powder to dissolve in water under stirring.

[0160] Dispersion is evaluated according to the following protocol:

[0161] An amount of 2.5 g of the yeast powder was added to a 25 mL graduated cylinder. Distilled water was added to the 25 mL graduation. The mixture was stirred for 3 hours, then the sedimented volume was measured. The dispersibility value is calculated as: ((Volumei - Volume2) / Volumei)*100 with Volumei being the initial volume in the cylinder (25 mL) and Volume2 being the sedimented volume after 3 hours.

[0162] 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.

[0163] 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 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 between 0.30 and 0.62.

[0164] The term "water holding capacity" refers to the amount of water that the powder can absorb per gram.

[0165] By "from 2.0 to 4.0 g of water / g of said debittered yeast powder" is meant: from 2.0 to 2.5 g of water / g of said debittered yeast powder, from 2.5 to 3.0 g of water / g of said debittered yeast powder, from 3.0 to 3.5 g of water / g of said debittered yeast powder and from 3.5 to 4.0 g of water / g of said debittered yeast powder.

[0166] The term "water activity" refers to the water vapor pressure of a gaseous atmosphere in equilibrium with the medium (here, the debittered yeast powder) divided by the saturated vapor pressure of that atmosphere at the same temperature. This represents the amount of free water available for biological reactions. Bacteria do not grow at a water activity below 0.7.

[0167] A debittered yeast powder having a water activity of 0.30 to 0.62 makes it possible to obtain a powder that is easy to store because microorganisms cannot develop inside it.

[0168] 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, 0.50 to 0.55, 0.55 to 0.60 and 0.60 to 0.62”.

[0169] 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; and • emulsifying stability of 75 to 100 minutes, particularly 85 to 95 minutes.

[0170] By “emulsifying activity” is meant the surface of the interface stabilized by a given concentration of material (here in debittered yeast powder).

[0171] By “from 40 to 80 g / m2” is meant: 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.

[0172] A debittered yeast powder having an emulsifying activity of 40 to 80 g / m2 makes it possible to give a uniform texture to a food product. It also makes it possible to improve the mouthfeel, palatability and uniform mixing of the ingredients.

[0173] 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.

[0174] By “75 to 100 minutes” is meant: 75 to 80 minutes, 80 to 85 minutes, 85 to 90 minutes, 90 to 95 minutes, 95 to 100 minutes.

[0175] A debittered yeast powder having an emulsifying stability of 75 to 100 minutes allows the use of this powder in food preparations requiring stability of the emulsion during its preparation, for example, in vegetable preparations.

[0176] 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 from 15 to 30%, in particular from 23 to 28%,

[0177] said minimum gelling concentration being expressed as a mass percentage.

[0178] 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.

[0179] The minimum gelling concentration is evaluated according to the following protocol:

[0180] Suspensions of samples of debittered yeast powder of (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 gelation concentration is determined as that where the sample has not fallen or slipped after inverting the test tube.

[0181] By “15 to 30%” we mean: 15 to 20%, 20 to 25%, 25 to 30%.

[0182] A debittered yeast powder having a minimum gelling concentration of 15 to 30% allows the formation of protein matrices contributing to the viscoelastic and solid properties of foods.

[0183] In a particular embodiment, the invention relates to a debittered yeast powder as defined above, said debittered yeast powder having a protein concentration of from 25 to 60%, in particular from 45 to 55%.

[0184] By “25 to 60%” we mean: from 25 to 30%, from 30 to 35%, from 35 to 40%, from 40 to 45%, from 45 to 50%, from 50 to 55%, from 55 to 60%.

[0185] 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,

[0186] 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 between 0.30 and 0.62,

[0187] and / or, • an emulsifying activity of 40 to 80 g / m2, in particular 55 to 65 g / m2; and • emulsifying stability of 75 to 100 minutes, in particular 85 to 95 minutes,

[0188] and / or,

[0189] having a minimum gelling concentration of 15 to 30%, in particular 23 to 28%,

[0190] said minimum gelling concentration being expressed as a mass percentage,

[0191] and / or,

[0192] having a protein concentration of 25 to 60%, in particular 45 to 55%.

[0193] In a particular embodiment, the invention relates to a debittered yeast powder as defined above, said debittered yeast powder comprising: • 20 to 30 mg of histidine / g of protein, in particular 22 mg of histidine / g of protein; • 40 to 50 mg of isoleucine / g of protein, in particular 47 mg of isoleucine / g of protein; • 70 to 80 mg of leucine / g of protein, in particular 72 mg of leucine / g of protein; • 70 to 80 mg of lysine / g of protein, in particular 78 mg of lysine / g of protein; • 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; • 45 to 55 mg of threonine / g of protein, in particular 51 mg of threonine / g of protein; • 10 to 20 mg of tryptophan / g of protein, in particular 15 mg of tryptophan / g of protein; and • 50 to 60 mg of valine / g of protein, in particular 57 mg of valine / g of protein.

[0194] 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 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, • 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 between 60 and 100, in particular between 75 and 95, • a water retention capacity of 2.0 to 4.0 g of water / g of said debittered yeast powder, in particular 3.0 to 3.5 g of water / g of said debittered yeast powder, • a water activity of between 0.30 and 0.62, • an emulsifying activity of 40 to 80 g / m2, in particular 55 to 65 g / m2, • 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%, particularly 45 to 55%.

[0195] The invention also relates to a method for manufacturing a debittered yeast powder as defined above.

[0196] Another aspect of the invention also relates to a method for manufacturing a powder of debittered yeasts, collected, optionally washed and inactivated, dried and optionally ground, said method comprising at least the steps of:

[0197] a. debittering comprising at least the steps:

[0198] i) culturing a brewing yeast resulting from brewing fermentation, in particular chosen from: Saccharomyces cerevisiae and Saccharomyces pastorius inoculated, at a rate of 10 to 100 g / L in a bioreactor, said culturing being carried out in a transition medium under conditions: • agitation from 25 to 1,000 rpm, • temperature between 4 and 37°C, in particular between 7 and 32°C,

[0199] said transition medium comprising: • from 0 to 50 g / L, of an ammonium or urea salt, corn solubles, pro-tamylasse • from 0 to 10 g / L, of a potassium salt, • from 0 to 5 g / L, of a magnesium salt MgSO4, • from 0 to 30 g / l equivalent, c|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, brewery spent grain, potato residue, bread production waste, dates, cane molasses, milling by-products, agri-food industry by-products, agri-food industries and mixtures thereof,

[0200] said carbon source being optionally treated enzymatically, in particular by an α-amylase or an amyloglucosidase, and • from 0 to 15 g / L of inactivated microorganism extract,

[0201] and whose pH is regulated and is between 3 and 10; and

[0202] ii) fed-batch non-draw-off discontinuous 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: • agitation between 100 and 1,000 rpm, and • temperature between 20 and 35°C,

[0203] said feed medium being added at a flow rate, in particular at a constant flow rate, of between 0.01 and 0.50 gg^ose equivalents / g biomass / h, for a period of between 6 and 72 hours,

[0204] said feeding medium comprising: • from 0 to 50 g / L, of an ammonium or urea salt, corn solubles, pro-tamylasse, • from 0 to 10 g / L, of a potassium salt, • from 0 to 5 g / L, of a magnesium salt MgSO4, • from 50 to 500 gg^ose equivalents / 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 fermented and drawn-off brewing yeast, brewery spent grain, potato residue, bread production waste, dates, corn, cane molasses, milling by-products, agri-food industry by-products, and mixtures thereof

[0205] said carbon source being optionally treated enzymatically, and • from 0 to 15 g / L of inactivated microorganism extract,

[0206] and whose pH is regulated and is between 3 and 10,

[0207] and optionally,

[0208] iii) a step of

[0209] continuous withdrawal

[0210] or

[0211] supplementation with a supplemented medium containing a brewing yeast resulting from continuous brewing fermentation, and continuous racking,

[0212] to obtain debittered yeasts;

[0213] b. collecting said debittered yeasts by filtration or centrifugation or simple decantation to obtain debittered and collected yeasts;

[0214] c. optionally washing said debittered and collected yeasts to obtain debittered, collected and optionally washed yeasts;

[0215] 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 0.5 to 180 min, at a temperature of 40 to 150°C;

[0216] and

[0217] optionally a step of inactivating said debittered yeasts obtained from at the end of step a, of said debittered and collected yeasts obtained at the end of step b, or of said debittered, collected and optionally washed yeasts obtained at the end of step c,

[0218] to obtain debittered and inactivated yeasts, collected and inactivated debittered yeasts or debittered, collected, inactivated and optionally washed yeasts,

[0219] said inactivation being carried out in an aqueous medium comprising from 1 to 30% of dry mass, for a duration of from 0.5 to 30 min, at a temperature of from 50 to 80°C; and

[0220] optionally 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,

[0221] said debittered, collected, optionally washed, inactivated, dried and possibly ground yeast powder 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;

[0222] 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.

[0223] In the expression "debittered, collected, optionally washed and inactivated, dried and possibly ground yeast powder", it is the yeasts which are debittered, collected, optionally washed and inactivated and it is the powder which is dried and possibly ground.

[0224] 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.

[0225] 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.

[0226] The fed-batch fermentation is still in progress during step iii) of continuous racking or supplementation with a supplemented medium containing a brewing yeast from the continuous brewing fermentation, and continuous racking.

[0227] The supplemented medium is a liquid medium containing a brewing yeast resulting from brewing fermentation.

[0228] Step iii) of continuous withdrawal has the advantage of extending the duration of each production cycle and thus reduce the costs linked to the implementation, emptying and cleaning of a fed-batch mode with equivalent production

[0229] 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 the implementation, emptying and cleaning of a fed-batch mode with equivalent production.

[0230] The method of manufacturing a debittered, collected and dried yeast powder of the invention comprises:

[0231] a debittering step a.,

[0232] a collection step b. and,

[0233] a drying step d.

[0234] The debittering step a. comprises at least:

[0235] culturing an inoculated brewing yeast in a transition medium i), and

[0236] fed-batch non-drafted batch fermentation using a feed medium or drawn-off fed fermentation of said brewing yeast ii).

[0237] The expression “cultivation” designates the act of making a microorganism (here, a brewing yeast) live and proliferate in the culture medium with the aim of increasing the biomass in the bioreactor.

[0238] The expression “inoculated into a bioreactor” designates the action of introducing a microorganism (here, a brewing yeast) into the culture medium of the bioreactor.

[0239] 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 to 70 g / L, from 70 to 80 g / L, from 80 to 90 g / L, from 90 to 100 g / L.

[0240] The expression "from 25 to 1000 rpm" means: from 25 to 100, from 100 to 200 rpm, from 200 to 300 rpm, from 300 to 400 rpm, from 400 to 500 rpm, from 500 to 600 rpm, from 600 to 700 rpm, from 700 to 800 rpm, from 800 to 900 rpm, from 900 to 1000 rpm.

[0241] The term "fed-batch fermentation" refers to a fermentation process in which the micronutrients and carbon source are introduced into the bioreactor during the process while the biomass remains inside the bioreactor during the process.

[0242] During non-drafted discontinuous fermentation (fed-batch), 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 with transition medium as well as the growth of the biomass change its composition at each moment of the process.

[0243] By "carbon source depletion" is meant that the carbon source concentration is 0 to 29 gg^ose equivalents / L, in particular 0 to 10 gg^œse equivalents / L.

[0244] The expression "constant flow rate" means that the flow rate does not vary beyond or below 10%.

[0245] The expression “from 6 to 72 hours” means: from 6 to 12 hours, from 12 to 18 hours, from 18 to 24 hours, from 24 to 30 hours, from 30 to 36 hours, from 36 to 42 hours, from 42 to 48 hours, from 48 to 54 hours, from 54 to 60 hours, from 60 to 66 hours, from 66 to 72 hours.

[0246] Collection step b. consists of collecting the yeasts that have undergone the debittering step.

[0247] The expression “simple decantation” designates the separation of the yeast phase from the aqueous phase (supernatant)

[0248] The drying step d. consists of removing free water available for biological reactions from the powder in order to decrease its water activity.

[0249] When drying is carried out by atomization, a grinding step is not necessary because at the end of the atomization drying a powder with a median particle size of 5 to 20 μm is obtained.

[0250] 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.

[0251] The method of manufacturing a debittered, collected, washed and dried yeast powder of the invention may comprise:

[0252] a washing step c. between the collecting step b. and the drying step d..

[0253] The method then comprises:

[0254] a debittering step a.,

[0255] a collection step b.,

[0256] a drying step d. as defined above and, a washing step c.

[0257] The optional washing step c. allows the removal of residual salts and carbon sources provided by the transition and feed media. It also allows the removal of possible cell lysis products (cell contents or walls) and metabolites generated by the yeasts. This washing consists of a resuspension and concentration of the debittered yeast.

[0258] 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.

[0259] The method then comprises:

[0260] a debittering step a.,

[0261] a collection step b.,

[0262] a drying step d. as defined above and, an inactivation step.

[0263] The optional inactivation step allows the suppression of the biological activity of the yeast under the effect of heat.

[0264] By “from 1 to 30% dry matter” is meant: from 1 to 5% dry matter; from 5 to 10% dry matter; from 10 to 15% dry matter; from 15 to 20% dry matter; from 20 to 25% dry matter and from 25 to 30% dry matter.

[0265] 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.

[0266] The method then comprises:

[0267] a debittering step a.,

[0268] a collection step b.,

[0269] a drying step d. as defined above and, a grinding step.

[0270] 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.

[0271] 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..

[0272] The method then comprises:

[0273] a debittering step a.,

[0274] a collection step b.,

[0275] a washing step c.,

[0276] a drying step d. and,

[0277] an inactivation step as defined above.

[0278] The method for manufacturing a debittered, collected, washed, dried and ground yeast powder 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.

[0279] The method then comprises:

[0280] a debittering step a.,

[0281] a collection step b.,

[0282] a washing step c.,

[0283] a drying step d. and,

[0284] a grinding step as defined above.

[0285] The process for manufacturing a powder of collected, dried, debittered yeasts, inactivated and ground 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..

[0286] The method then comprises:

[0287] a debittering step a.,

[0288] a collection step b.,

[0289] a drying step d.,

[0290] an inactivation step and,

[0291] a grinding step as defined above.

[0292] The method for manufacturing a powder of collected, washed, dried, inactivated and ground debittered yeasts 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..

[0293] The method then comprises:

[0294] a debittering step a.,

[0295] a collection step b.,

[0296] a washing step c.,

[0297] a drying step d.,

[0298] an inactivation step and,

[0299] a grinding step as defined above.

[0300] In a particular embodiment, the invention relates to a manufacturing method as defined above of a powder of debittered, collected, optionally washed and inactivated, dried and optionally ground yeasts, said powder of debittered, collected, optionally washed, inactivated, dried and optionally ground yeasts 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.

[0301] The method according to the invention may contain a step of inoculation of the brewing yeast prior to the culturing of said brewing yeast.

[0302] In a particular embodiment, the invention relates to a manufacturing process as defined above of a powder of debittered yeasts, collected, optionally washed and inactivated, dried and possibly ground, said process comprising at least the steps of:

[0303] a. debittering comprising at least the steps:

[0304] e) inoculation of 10 to 100 g / L, in particular of 20 to 50 g / L (and more particu (limited to 40 g / L), of a brewing yeast from brewing fermentation, in particular chosen from: Saccharomyces cerevisiae and Saccharomyces pastorius, in a bioreactor,

[0305] i) culturing said brewing yeast, said culturing being carried out in a transition medium under conditions: • stirring speed from 25 to 1,000 rpm, in particular from 200 to 800 rpm, and • temperatures between 4 and 37°C, in particular between 7 and 32°C,

[0306] said transition medium comprising: • from 0 to 50 g / L, in particular 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 1 g / L, of a magnesium salt MgSO4, • from 0 to 30 gg^ose equivalents / L, in particular from 0 to 5 gg^ose equivalents / L, from a source of carbon selected 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, brewery spent grain, potato residue, bread production waste, dates, cane molasses, milling by-products, food industry by-products, food industries and mixtures thereof,

[0307] 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,

[0308] and whose pH is regulated and is between 3 and 10, in particular between 4 and 7; and

[0309] ii) fed-batch fermentation, after exhaustion from the carbon source of said transition medium, to obtain deamerized yeasts, said fed-batch being carried out using a feeding medium under conditions: • stirring speed of 100 to 1,000 rpm, in particular 200 to 800 rpm, and • temperature of 20 to 35°C,

[0310] said feed medium being added at a flow rate, in particular at a constant flow rate, of from 0.01 to 0.50 gg^eequivalents / g biomass / h, in particular of from 0.10 to 0.15 ggiucœeequivalents / g biomass / h, for a period of from 6 to 72 hours, in particular from 24 to 48 hours,

[0311] said feeding medium comprising: • from 0 to 50 g / L, in particular 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 1 g / L, of a magnesium salt MgSO4, • from 50 to 500 gglucose equivalent / L, in particular from 150 to 250 gglucose equivalent / L xlc preferably from 175 to 225 gg^ose equivalents / 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 by-products, food industry by-products, and mixtures thereof

[0312] 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,

[0313] and whose pH is regulated and is between 3 and 10, in particular between 4 and 7,

[0314] and possibly,

[0315] iii) a step of

[0316] continuous withdrawal

[0317] or

[0318] supplementation with a supplemented medium containing a brewing yeast resulting from continuous brewing fermentation, and continuous racking,

[0319] to obtain debittered yeasts;

[0320] b. collecting said debittered yeasts by filtration or centrifugation or simple decantation to obtain debittered and collected yeasts;

[0321] c. optionally washing said debittered and collected yeasts to obtain debittered, collected and optionally washed yeasts;

[0322] 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 time of 0.5 to 180 min, in particular 120 min, at a temperature of 40 to 150°C, in particular 50°C; and

[0323] 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,

[0324] to obtain debittered and inactivated yeasts, collected and inactivated debittered yeasts or debittered, collected, inactivated and optionally washed yeasts,

[0325] 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 time of from 0.5 to 30 min, in particular 15 min, at a temperature of from 50 to 80°C, in particular 60°C; and

[0326] optionally 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,

[0327] said debittered, collected, optionally washed, inactivated, dried and possibly ground yeast powder 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;

[0328] 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.

[0329] In a particular embodiment, the invention relates to a manufacturing method as defined above of a powder of debittered, collected, optionally washed and inactivated, dried and optionally ground yeasts, said powder of debittered, collected, optionally washed, inactivated, dried and optionally ground yeasts 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.

[0330] 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,

[0331] said debittered, collected, optionally washed, inactivated, dried and possibly ground yeast powder 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 between 60 and 100, in particular between 75 and 95, • a water retention capacity of 2.0 to 4.0 g of water / g of said debittered yeast powder, in particular 3.0 to 3.5 g of water / g of said debittered yeast powder, • a water activity of between 0.30 and 0.62, • an emulsifying activity of 40 to 80 g / m2, in particular 55 to 65 g / m2, • 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%, particularly 45 to 55%.

[0332] In a particular embodiment, the invention relates to a method as defined above, in which said culturing step ai) is carried out under pO2 conditions of from 0 to 100%, in particular from 20 to 60%.

[0333] The expression “pO2” designates the relative concentration of dissolved oxygen in the fermentation must at saturation.

[0334] In this embodiment, the consumption of oxygen by the yeasts is not a limiting factor in the transformation of sugars into biomass.

[0335] In a particular embodiment, the invention relates to a process as defined above, in which said fed-batch step a.ii) is carried out under pO2 conditions of from 0 to 100%, in particular from 20 to 60% and more particularly from 35 to 45%.

[0336] In this embodiment, the consumption of oxygen by the yeasts is not a limiting factor in the transformation of the carbon source provided by the feed medium into biomass.

[0337] 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 or an amyloglucosidase.

[0338] In a particular embodiment, the invention relates to a method as defined above, in which said transition medium is treated enzymatically, in particular by an α-amylase or an amyloglucosidase.

[0339] In a particular embodiment, the invention relates to a method as defined above, in which said transition medium is not treated enzymatically.

[0340] In a particular embodiment, the invention relates to a method as defined above, in which said transition 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).

[0341] In a particular embodiment, the invention relates to a method as defined above, in which said feed medium is optionally treated enzymatically, in particular by an α-amylase or an amyloglucosidase.

[0342] In a particular embodiment, the invention relates to a method as defined above, in which said feed medium is treated enzymatically, in particular by an α-amylase or an amyloglucosidase.

[0343] In a particular embodiment, the invention relates to a method as defined above, in which said feed medium is not enzymatically treated.

[0344] In a particular embodiment, the invention relates to a method as defined above,

[0345] wherein said culturing step a.ii) is carried out under pO 2 conditions of from 0 to 100%, in particular from 20 to 60% and more particularly from 35 to 45%,

[0346] and / or,

[0347] wherein said fed-batch step a.iii) is carried out under pO2 conditions of 0 to 100%, in particular 20 to 60% and more particularly 35 to 45%,

[0348] and / or,

[0349] wherein said transition medium is optionally enzymatically treated.

[0350] In a particular embodiment, the invention relates to a method as defined above, in which said feed medium further comprises: • mineral salts chosen from: ZnSO4, CaCl2, FeSO4, H3BO3, CuSO4, Na2MoO4, MnCl2, CoCl2, KCI and their mixtures; 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).

[0351] The method according to the invention may also comprise at least three steps prior to steps a. e) of inoculation or ai) of culturing.

[0352] In a particular embodiment, the invention relates to a method as defined above, said method further comprising and upstream of said step a. e) of inoculation or ai) of culturing,

[0353] at least one step I of withdrawing a brewing yeast during brewing fermentation, in particular after primary fermentation, to obtain a withdrawn brewing yeast; and optionally at least the steps of:

[0354] II of sedimentation of said drawn-off brewing yeast to obtain drawn-off and sedimented brewing yeast, and a supernatant; and / or

[0355] 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% in dry matter, said percentage in dry matter being expressed in mass concentration.

[0356] The method for manufacturing a debittered, collected and dried yeast powder of the invention further comprises and upstream of said step a. e) of inoculation or ai) of culturing:

[0357] a withdrawal step I, and optionally

[0358] a sedimentation step II and / or,

[0359] a concentration step III

[0360] 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. e) of inoculation or ai) of culturing:

[0361] a drawing-off step I.

[0362] 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. e) of inoculation or ai) of culturing:

[0363] a drawing-off step I, and

[0364] an IL sedimentation step

[0365] The process for manufacturing a debittered, collected, washed and dried yeast powder of the invention may further comprise and upstream of said step a. e) inoculation or ai) cultivation:

[0366] a drawing-off step I, and

[0367] a concentration step III.

[0368] The method for manufacturing a debittered, collected, washed and dried yeast powder of the invention may further comprise and upstream of said step a. e) of inoculation or ai) of culturing:

[0369] a drawing-off step I, and

[0370] a sedimentation step II, and

[0371] a concentration step III.

[0372] The advantage of using a drawn, sedimented and concentrated brewing yeast is to be able to control the supply of fermented must into the medium.

[0373] In a particular embodiment, the invention relates to a method as defined above, said drawn-off, sedimented and concentrated brewing yeast being a brewing yeast resulting from brewing fermentation.

[0374] In a particular embodiment, the invention relates to a process as defined above, 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%.

[0375] By "primary fermentation" is meant the stage of exponential growth of yeasts during which the latter converts most of the sugars into alcohol and carbon dioxide.

[0376] By “viability” is meant the rate of live yeasts, measured using methylene blue.

[0377] The method according to the invention can use brewing yeasts resulting from brewing fermentation which are considered in the state of the art to have a high content of alpha acids, beta acids and purines.

[0378] 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 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 0.2 to 4 mg of beta acids / g of debittered yeasts, in particular from 0.3 to 0.6 mg of beta acids / g of debittered yeasts, said beta acids being in particular lupulone, adlupulone and colupulone.

[0379] 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

[0380] [Fig-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 and is expressed in grams and the accumulation of ethanol is represented with circles and is expressed in grams.

[0381] [Fig.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. The monitoring of the biomass is represented with triangles and is expressed in grams, and the accumulation of ethanol is represented with circles and is expressed in grams.

[0382] [Fig.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 and is expressed in grams, the accumulation of ethanol is represented with circles and is expressed in grams.

[0383] [Fig.4] represents the evolution as a function of time (hours): - biomass represented by triangles and expressed in grams - alpha acid and glucose content, represented with squares and expressed in pg / g of Saccharomyces cerevisae biomass - and that of ethanol, represented by circles and expressed in grams, in the bioreactor of Example 4 below.

[0384] [Fig.5] represents a general diagram of the manufacturing process of a debittered yeast powder. (1) represents the mixing tank. (2) represents the heat exchange. (3) represents the centrifugal decanter (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.

[0385] [Fig.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 centrifugal decanter (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 ammonium sulfate (NH4)2SO4 (10 g / L), potassium phosphate K 2HPO4 (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 the feeding medium, comprising a carbon source (200 g / L) of 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 of transition phase and 46h of feeding phase, at pO2 = 40%, pH = 5 and T = 30°C) at a flow rate of 0.125 to 0.2 g / L of glucose equivalent / g biomass / h. (E) corresponds to 10 min at 2700g. (F) corresponds to a ratio of milliQ water volume / volume of the transition and feeding media mixture of 5. (G) corresponds to 10 min at 60°C. (H) corresponds to 10 min at 2700g. (I) corresponds to 60°C for 2h. (J) corresponds to grinding with an ultra-centrifugal mill with a 0.12 mm sieve and a speed of 1500 rpm. Examples

[0386] 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 medium favorable to growth, by progressively adding a feeding medium, so as to propagate a new biomass of yeasts and thus reduce the concentration of bitter molecules to the perception threshold.

[0387] The objective of the experiment described in this document is to propagate the biomass of the yeast Saccharomyces cerevisae from beer production. For this, the yeasts are introduced into a bioreactor in a transition medium which allows the 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.).

[0388] EXAMPLE 1 Propagation of biomass with glucose

[0389] 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.

[0390] 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. The supernatant was then removed to concentrate the yeasts, which were then inoculated into the bioreactor at a concentration of 20 g / L. The aim of this process is to replicate brewing fermentation and the yeast deposit of breweries.

[0391] The initial transition medium is composed of milliQ water (IL), ammonium sulfate (NH4)2SO4 (18 g), potassium phosphate KH2PO4 (2.944 g), MgSO4 (0.81 g), yeast extract (1 g) and glucose (5 g).

[0392] Each of these compounds was autoclaved separately beforehand to ensure its sterility.

[0393] 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 linked to the measured dissolved oxygen pressure value.

[0394] From 2h 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 was added at a rate of 0.05 ggiucose / yeast / ^ between 2 and 14h then 0.25 ggiucose / yeast / ^ between 14h and 38h (final time).

[0395] 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 2 hours at 105°C and then weighing a 10 mL 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® 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®.

[0396] After 39h of the run, the yeasts were collected and centrifuged in autoclaved 250 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 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 2h and finally ground in a grinder.

[0397] Extraction and quantification of glutathione were carried out according to patent EP1706478B1. 10 mL of 0.1 N HCl were added to a centrifuge tube containing 0.4 g of yeasts 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 into 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 given in patent EP1706478B1 (example 1). Results

[0398] [Fig. 1] represents an example of the propagation of brewer's yeast in a bioreactor for the purpose of 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.

[0399] 43.6 grams of S. cerevisae yeasts, from an initial biomass of 19.4 g, have were produced under these conditions, a multiplication of 2.24.

[0400] The initial 5 grams of glucose were consumed by the yeasts in the first 2 hours of the run. From 2h, the feeding medium was added. The addition rate is 0.05 between 2 and 14h then 0.25 between 14h and 38h (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 their propagation.

[0401] Ten grams of ethanol were initially present in the culture medium, which comes from the beer medium inoculated with the yeasts. After 14h, 5 grams of ethanol were consumed by the yeasts, this being also used as a carbon source for yeast propagation. Increasing the flow rate of the feed medium from 14h leads to the accumulation of ethanol in the bioreactor, which is then re-consumed by the yeasts until the end of the run.

[0402] The measured glutathione content is 9.11 mg of glutathione / g of yeast.

[0403] EXAMPLE 2 Biomass propagation with glucose at 20L scale

[0404] 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.

[0405] 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. The supernatant was then removed to concentrate the yeasts, which were then inoculated into the bioreactor at a concentration of 20 g / L. This process aims to replicate brewing fermentation and the yeast deposit of breweries.

[0406] 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 (8 g) and sucrose (40 g).

[0407] Each of these compounds was autoclaved separately upstream to ensure its sterility.

[0408] 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, an incoming air flow rate of 10 L / minute, and stirring at 800 RPM. The dissolved oxygen pressure is measured by a probe added to the bioreactor.

[0409] The feeding 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 debittered product is obtained) the feeding is set up at a rate of 0.15 g / yeast / h up to 48 hours, corresponding to the end of the run.

[0410] 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 3 hours at 105°C then weighing a 10 mL 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®

[0411] After 48h 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 medium, 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 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

[0412] [Fig.2] represents an example of the propagation of brewer's yeast in a bioreactor for the purpose of debittering it. 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 feeding medium whose carbon source (here, sucrose) is converted into biomass.

[0413] 357 grams of S. cerevisae yeasts, from an initial biomass of 125.4 g, have were produced under these conditions, a multiplication of 2.8.

[0414] The initial 5 grams of sucrose were consumed by the yeasts in the first 2 hours of the run. From 2h, the feeding medium was added. The addition rate is 0.15 µg ...

[0415] 72.2 grams of ethanol were initially present in the culture medium, which comes from the beer medium inoculated with yeast. After 24 hours, all of the ethanol has been consumed by the yeast, 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.

[0416] EXAMPLE 3 Propagation of biomass with beet molasses

[0417] 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.

[0418] 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. The supernatant was then removed to concentrate the yeasts, which were then inoculated into the bioreactor at a concentration of 20 g / L. This process aims to replicate brewing fermentation and the yeast deposit of breweries.

[0419] Beetroot molasses (France Mélasses) were diluted by two to obtain 200 glucose equivalents / L and then clarified by centrifugation for 40 minutes, at 4000 rotations per minute (RPM) at 15°C.

[0420] The initial transition medium present in the bioreactor consists of milliQ water (IL), beet molasses at 5 gg^oseequivalent / l through the molasses, 5.4g / L of potassium phosphate (KH2PO4) and 11.42 g / L of ammonium sulfate (NH4)2SO4.

[0421] Each of these compounds was autoclaved separately beforehand to ensure its sterility.

[0422] The physicochemical parameters of the bioreactor were set at a pH=5, automatically regulated using a probe by a basic 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.

[0423] From 2h of run, the autoclaved feeding medium composed of molasses of beetroot diluted to 200 gglucose equivalent / ]^, added at a rate of 0.4 gglucose equivalent / g yeast / h.

[0424] Throughout the run, the increase in biomass was assessed in the same manner as in Example 1.

[0425] After 48h of the run, the yeasts were collected, centrifuged and ground in the same way as in Example 1. Results

[0426] [Fig.3] represents an example of the propagation of brewer's yeast in a bioreactor supplemented with beet molasses for the purpose of debittering it. 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 (feed medium) whose carbon source (in the form of sucrose) is converted into biomass.

[0427] 49 grams of S. cerevisae yeasts, from an initial biomass of 21 g, were produced thanks to these conditions, i.e. a multiplication of 2.34, with a maximum of 57.5 g of yeast produced reached at 30 hours (i.e. a multiplicative factor of 2.74).

[0428] The initial 5 grams of sucrose were consumed by the yeasts within the first 2 hours of the run. From 2 hours onwards, the feed medium was added. The addition rate was maintained at a target value of 0.4 g / L equivalent / yeasts / fr. The method of adding the sugar gradually via the feed medium ensures a low quantity of carbon source (here, mainly in the form of sucrose) instantaneously 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 their propagation.

[0429] 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 feeding 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 the propagation of the yeasts, to reach a final quantity of 14g.

[0430] EXAMPLE 4 Propagation of biomass with glucose and measurement of the concentration of bitter molecules

[0431] Spent Brewers Yeasts (SBY) 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.

[0432] After the 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 IL bioreactor at a concentration of 20 g / L. This process aims to replicate brewing fermentation and the yeast deposit of breweries.

[0433] 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 8mg / L, riboflavin (2mg / L), calcium pantothenate (4 mg / L), ZnSO4 (4 mg / L), FeSO4 (lOmg / L), CaCl2 (lOOmg / L).

[0434] Each of these compounds was autoclaved separately upstream to ensure its sterility.

[0435] The physicochemical parameters of the bioreactor were set at a 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 8h 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).

[0436] From 2h 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 0.125 g giucose / g yew / ^ until 24h, then the rate was adjusted to 82 g giucose / g yew / h from 24h, then was increased to 90 g giucose / g yew / ^ from 31h.

[0437] Throughout the duration of the run, the increase in biomass was evaluated by measuring the dry weight (centrifugation, drying for 2 hours at 105°C then by weighing a 5mL sample of the propagation medium.

[0438] The ethanol concentration in the medium was evaluated 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 pL, and the column was maintained at 30°C. The samples were eluted isocratically by 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 by 0.2 pm RC filters. Measurement of the concentration of bitter molecules

[0439] 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.

[0440] Each sample was subjected to ultrasound at room temperature for 30 min, was centrifuged at 4000 g for 5 minutes and then filtered using a 0.2 μm polytetrafluoroethylene (PTFE) filter.

[0441] The samples were then passed through an HPLC column (accucore™ aQ C18 from Fischer Scientific) using a gradient of acetonitrile and formic acid.

[0442] A sensory evaluation of the samples is also carried out.

[0443] The quantification of the contaminating bacterial flora (originating from SBY) is evaluated by counting on Petri dishes (PCA counting agar), from the Biokar® brand. Results

[0444] [Fig.4] represents an example of the propagation of brewer's yeast in a bioreactor with a view to its debittering. Growth is 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 is controlled by the addition of glucose (feeding medium) whose carbon is converted into biomass.

[0445] 7.8 grams of S. cerevisae yeasts were produced under these conditions, from with an initial biomass of 28.1 g, i.e. a multiplication of 3.6 in 48 hours.

[0446] The initial 5 grams of glucose were consumed by the yeasts in the first 2 hours of the run. From 2h, the feeding medium was added. The addition rate allows a conversion yield of sugar (carbon source) into biomass of 0.22 gh'™'"^7g glucose. The fa^ cp adding the sugar gradually through the feeding medium ensures a low quantity 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 their propagation.

[0447] 7 grams of ethanol are initially present in the culture medium, which comes from the beer medium inoculated with yeasts. After 24 hours, all the ethanol has been consumed by the yeasts, which is also 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.

[0448] The alpha acids adsorbed to the yeasts gradually decrease until they stabilize after 30 hours from the start of the process. This decrease is mainly due to the dilution of the bitter molecules in relation to the increase in biomass. However, the total alpha acids bound to the yeasts increase from 2.8 mg at T0 to 1.3 mg at T48 ([Fig.l]).

[0449] EXAMPLE 5 Propagation of biomass with cane molasses

[0450] The used brewery yeasts have the same origin and were inoculated in the same way as in Example 3.

[0451] The cane molasses are diluted by two to obtain 200 gslucose equivalent / L and are then clarified by centrifugation for 40 minutes, at 4000 RPM at 15°C.

[0452] The initial transition medium present in the bioreactor consists of milliQ water (IL), at 5 gg^coseequivalent / l through molasses, 5.4g / L of potassium phosphate (KH2 PO4) and 11.42 g / L of ammonium sulfate ((NH4)2SO4).

[0453] Each of these compounds is autoclaved separately upstream to ensure its sterility.

[0454] The physicochemical parameters of the bioreactor are set at a 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%, agitation between 100 and 800 rpm linked to the measured dissolved oxygen pressure value.

[0455] From 2h of run, the autoclaved feeding medium composed of cane molasses diluted to 200 g glucose equivalent / L, csl added a flow rate of 0.4 g glucose / g yeast / h.

[0456] Throughout the run, the increase in biomass was assessed in the same manner as in Example 1.

[0457] After 48h of the run, the yeasts were collected, centrifuged and ground in the same manner as in Example 1.

[0458] EXAMPLE 6 Propagation of biomass with onion crop residues

[0459] The used brewery yeasts have the same origin and were inoculated in the same way as in Example 3.

[0460] 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 into the solution at 70°C for 1h to remove the sulfurous odor. This solution is clarified by centrifugation for 10 minutes, at 4000 RPM at 15°C, to obtain 100 gg^ose equivalent / L

[0461] The initial transition medium present in the bioreactor consists of milliQ water (IL), 5 gg^cose equivalent / 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).

[0462] Each of these compounds is autoclaved separately upstream to ensure its sterility.

[0463] 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.

[0464] From 2h of run, the autoclaved feed medium composed of residues of onion culture diluted to 100 μg^ose equivalents / L, is added at a rate of 0.4 g glucose / g yeast / h.

[0465] Throughout the run, the increase in biomass was assessed in the same manner as in Example 1.

[0466] After 48h of the run, the yeasts were collected, centrifuged and ground in the same manner as in Example 1.

[0467] EXAMPLE 7 Propagation of biomass with potato residues

[0468] The used brewery yeasts have the same origin and were inoculated in the same way as in Example 3.

[0469] Potato residues (consisting of potato pulp, peelings) are dried for 2 hours 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 brought into contact with the enzyme mix ENDOZYM Brewmix Plus (α-amylase, protease, cellulase, [3-glucanase) at a rate of 25 mL / Le, at 60°C, at pH = 6 for 2 hours and at 100 RPM. They are then put into contact with ENDOZYM AMG (amyloglucosidase, EC 3.2.1.3) at a level of 500pL / L at 65°C, at pH = 5 for 1 hour and at 100 RPM.

[0470] This solution is clarified by centrifugation for 40 minutes, at 4000 RPM at 15°C.

[0471] The initial transition medium is composed of milliQ water (IL), hydrolyzed solution of potato residues (5gglucose / L), ammonium sulfate (NH4)2SO4 (10 g / L), potassium phosphate KH2PO4 (5 g / L), yeast extract (Ig / L).

[0472] Each of these compounds is autoclaved separately upstream to ensure its sterility.

[0473] 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.

[0474] From 2h of run, the autoclaved feeding medium composed of potato residues reaching 100 gg^ose equivalents / L, is added at a rate of 0.4 g of glucose / g of yeast / h.

[0475] EXAMPLE 8 Biomass propagation with beer production deviations

[0476] The used brewery yeasts have the same origin and were inoculated in the same way as in Example 2.

[0477] The beer production gaps are brought into contact with ENDOZYM AMG (amyloglucosidase, EC 3.2.1.3) at a rate of 250pL / L of beer production gaps at 50°C, at pH = 5 for 1h30 and at 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

[0478] The initial transition medium present in the bioreactor consists of the hydrolyzed solution of beer residues (IL, 10gglucose / L and 60g / L of ethanol), ammonium sulfate (NH4)2SO4 (10 g / L), potassium phosphate KH2PO4 (5 g / L), yeast extract (lg / L).

[0479] Each of these compounds is autoclaved separately upstream to ensure its sterility.

[0480] The physicochemical parameters of the bioreactor are set at a 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.

[0481] From 2h of run the autoclaved feed medium composed of the beer production gaps diluted to a concentration of 10 gg^ose equivalents / L and 60g / L of ethanol, is added at a rate of 0.4 g of gg^ose equivalents / g yeast / h.

[0482] Throughout the run, the increase in biomass was assessed in the same manner as in Example 1.

[0483] After 48h of the run, the yeasts were collected, centrifuged and ground in the same manner as in Example 1.

[0484] EXAMPLE 9 Biomass propagation with beer production gaps as the transition medium carbon source, and with beet molasses as the feed medium carbon source

[0485] The used brewery yeasts have the same origin and were inoculated in the same way as in Example 2.

[0486] The treatment of the carbon source, the transition medium and the reactor parameters are the same as in Example 9.

[0487] From 2h of run, the autoclaved feeding medium composed of beet molasses diluted to 200 gg^ose equivalents / L, was added at a rate of 0.4 gg^ose equivalents / g yeast / h.

[0488] Throughout the run, the increase in biomass was assessed in the same manner as in Example 1.

[0489] After 48h of the run, the yeasts were collected, centrifuged and ground in the same manner as in Example 1.

[0490] EXAMPLE 10 Propagation of biomass with dates

[0491] The used brewery yeasts have the same origin and were inoculated in the same way as in Example 3.

[0492] 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 g / L (the extracted sugars are a mixture of glucose, fructose and sucrose). A dilution is carried out to obtain 100 g / L.

[0493] The initial transition medium present in the bioreactor consists of milliQ water (IL), 5g giucœequivalent / L via the date solution, ammonium sulfate (NH4)2SO4 (10 g / L), potassium phosphate KH2PO4 (5 g / L), yeast extract (Ig / L).

[0494] Each of these compounds is autoclaved separately upstream to ensure its sterility.

[0495] 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.

[0496] From 2h of run, the autoclaved feeding medium composed of dates diluted to 100 g glucose equivalent / L, csj added at a flow rate of 0.4 g glucose / g yeast / h.

[0497] Throughout the run, the increase in biomass was assessed in the same manner as in Example 1.

[0498] After 48h of the run, the yeasts were collected, centrifuged and ground in the same manner as in Example 1.

[0499] then dried in an oven at 50°C for 2 hours and ground in a grinder.

[0500] EXAMPLE 11 Biomass propagation with milling production gaps

[0501] The used brewery yeasts have the same origin and were inoculated in the same way as in Example 3.

[0502] The milling production deviations are ground using a mortar and then an ultracentrifugal mill (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 the 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, NS50010 250U / 100g of co-product, NS50014 225U / 100g of co-product, NS50030 150U / 100g of co-product) at 50°C, at pH = 5.5 for 48 hours. The solution is then brought into contact with 350 mg / kg of Novozyme brand Liquozyme SC DS at 85°C) pH = 5.8 for 4 hours. This solution is diluted to obtain 100 gglucose equivalent / L.

[0503] The initial transition medium present in the bioreactor consists of milliQ water (IL), 5 gglucose / L of the hydrolyzed solution of milling production deviations, ammonium sulfate (NH4)2SO4 (10 g / L), potassium phosphate KH2PO4 (5 g / L), yeast extract (Ig / L).

[0504] Each of these compounds is autoclaved separately upstream to ensure its sterility.

[0505] The physicochemical parameters of the bioreactor are set at a pH=5, automatically regulated using a probe by a basic solution (NaOH at 1 mol / L), a temperature temperature of 30°C, a dissolved oxygen pressure of 40%, agitation between 100 and 800 rpm related to the measured dissolved oxygen pressure value.

[0506] From 2 hours of run, the autoclaved feeding medium composed of the milling production deviations diluted to 100 gg^ose equivalent / L, is added at a rate of 0.4 g of glucose / g of yeast / h.

[0507] Throughout the run, the increase in biomass was assessed in the same manner as in Example 1.

[0508] After 48h of the run, the yeasts were collected, centrifuged and ground in the same manner as in Example 1.

[0509] EXAMPLE 12 Propagation of biomass with bread residues

[0510] The used brewery yeasts have the same origin and were inoculated in the same way as in Example 3.

[0511] 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 (a-amylase, EC 3.2.1.1) at a rate of 25mL / L at 70°C, at pH = 6 for 2h. They are then brought into contact with 500pL / L of ENDOZYM AMG (amyloglucosidase, EC 3.2.1.3) at 50°C, at pH = 5 for 1h and at 100 RPM.

[0512] This solution is clarified by centrifugation for 40 minutes, at 4000 RPM at 15°C.

[0513] The initial transition medium is composed of milliQ water (IL), hydrolyzed solution of bread residues (5gglucose / L), ammonium sulfate (NH4)2SO4 (10 g / L), potassium phosphate KH2PO4 (5 g / L), yeast extract (Ig / L).

[0514] Each of these compounds is autoclaved separately upstream to ensure its sterility.

[0515] 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.

[0516] From 2 hours of run, the autoclaved feeding medium composed of the solution of bread residues at 100 gg^ose equivalents / L, is added at a rate of 0.4 g of glucose / g of yeast / h.

[0517] Throughout the run, the increase in biomass was assessed in the same manner as in Example 1.

[0518] After 48h of the run, the yeasts were collected, centrifuged and ground in the same manner as in Example 1.

[0519] EXAMPLE 13 Propagation of biomass using a continuous process

[0520] Spent Brewer's Yeast (SBY) was obtained by fermentation (7 days) of a malt extract must (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.

[0521] 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. The supernatant was then removed to concentrate the yeasts, which were then inoculated into the bioreactor at a concentration of 20 g / L. This process aims to replicate brewing fermentation and the yeast deposit of breweries.

[0522] The initial transition medium is composed of milliQ water (IL), ammonium sulfate (NH4)2SO4 (10 g), potassium phosphate KH2PO4 (5 g), MgSO4 (0.81 g), yeast extract (1 g) and glucose (5 g).

[0523] Each of these compounds was autoclaved separately beforehand to ensure its sterility.

[0524] The physicochemical parameters of the bioreactor were set at a pH=5, automatically regulated using a probe with a basic solution (NaOH at 1 mol / L), a temperature of 30°C, a dissolved oxygen pressure of 40%, agitation between 100 and 800 rotations per minute linked to the measured dissolved oxygen pressure value.

[0525] From 2h 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 / L (flow rate of 0.25 mL / min).

[0526] From 12h of run, a second feeding 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 yeasts / h).

[0527] From 14 hours of run, the medium withdrawal is set up at a flow rate of 0.34 mL / min.

[0528] Throughout the run, the evolution of the biomass was evaluated by measuring the optical density (OD) at 600 nm using a spectrophotometer and by measuring the dry weight (washing, centrifugation, drying for 2 hours at 105°C then weighing a sample of 10 mL of the propagation medium). The ethanol concentration in the medium was evaluated using an enzymatic ethanol assay kit marketed by Oenolab Diagnostics. 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 evaluated by counting on Petri dishes (Plate Count Agar (PCA)) marketed by Biokar®.

[0529] As the run progressed, the yeasts were collected and centrifuged in autoclaved 250 mL plastic bottles, then washed 3 times with sterile milliQ water to remove salts, carbon sources from the feeding 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 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, were ground in a grinder.

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, in particular chosen from: Saccharomyces cerevisiae and Saccharomyces pastorius, 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 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 1 g / L, of a magnesium salt MgSO4, • from 0 to 30 gglucose equivalents / L, in particular from 0 to 5 gg|iim^ equivalents / 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 grains, potato residue, bread production waste, dates, cane molasses, milling by-products, food industry by-products, 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 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 10 g / L, of a salt ammonium 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 1 g / L, of a magnesium salt MgSO4, • from 50 to 500 gglucose equivalent / ^, in particular from 150 to 250 gglucose equivalent / L (preferably 175 to 225 µg^ose 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, brewery spent grain, potato residue, bread production waste, dates, cane molasses, milling co-products, food industry co-products, and mixtures thereof, ethanol, preferably glucose, sucrose, maltose, maltotriose, ethanol, beet molasses, bread production gaps,potato residue or beer production waste consisting of or including the supernatant from the sedimentation of 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; 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,

2. adhumulone and humulone; and / or • a reduction of at least 50% in the content of beta acids, said beta acids being in particular lupulone, adlupulone and colupulone. 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 pastorius, 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, in particular 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 1 g / L, of a magnesium salt MgSO4, • from 0 to 30 gglucose equivalents / L, in particular from 0 to 5 gg|iim^ equivalents / 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 grains, potato residue, bread production waste, dates, cane molasses, milling by-products, food industry by-products, 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 feed 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, in particular from 0 to 10 g / L, of an ammonium salt chosen from: (NEL^HPO^ (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 1 g / L, of a magnesium salt MgSO4, • from 50 to 500 μg glucose equivalents / L, in particular from 150 to 250 μg glucose equivalents / L, preferably from 175 to 225 μg glucose equivalents / 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, agri-food industry by-products, ethanol and mixtures thereof, preferably glucose, sucrose, maltose, maltotriose, ethanol, beet molasses, bread production waste,potato residue or beer production waste consisting of or including the supernatant from the sedimentation of 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;

3. 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 co-humulone, 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. 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 particular, said transition medium comprising 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 optionally enzymatically treated. Use according to any one of claims 1 to 2, wherein 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)

4. 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 B 5 (calcium pan-tothenate) 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 (para-aminobenzoic acid) at a rate of 0 to 2mg / L and their mixtures; and / or • peptone at a rate of 0 to 20 g / L; and / or • Yeast Nitrogen Base (YNB). Use according to any one of claims 1 to 3, wherein said feed medium comprises a carbon source selected from: beer production waste consisting of or comprising the supernatant from the sedimentation of 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 fermented and drawn-off brewing yeast, said carbon source optionally being enzymatically treated, and optionally 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).

5. 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 co-humulone, 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; and 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 from 5 to 200 pm, in particular from 6 to 80 pm, in particular from 8 to 30 pm.

6. Debittered yeast powder according to claim 5, 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 between 0.30 and 0.62, and / or, • an emulsifying activity of 40 to 80 g / m2, in particular 55 to 65 g / m2; and • 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%.

7. Process for manufacturing a powder of debittered yeasts, collected, optionally washed, inactivated, dried and possibly ground, said process comprising at least the steps of: a. debittering comprising at least the steps of: i) culturing a brewing yeast resulting from brewing fermentation, in particular chosen from: Saccharomyces cerevisiae and Sac-charomyces pastorius inoculated, at a rate of 10 to 100 g / L in a bioreactor, said culturing being carried out in a transition medium under conditions: • agitation between 25 and 1,000 rpm, and • temperatures between 4 and 37°C, in particular 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 MgSO4, • from 0 to 30 ggi^e equivalent / L of a chosen carbon source among: 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, brewer's grains, potato residue, bread production deviations, dates, cane molasses, co milling products, by-products of the agri-food industry, and their mixtures, said carbon source being optionally treated enzymatically, 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 in real time and is between 3 and 10, and ii) fed-batch fermentation of said brewing yeast cultured, after exhaustion of the carbon source of said transition medium, to obtain de-amerized yeasts, said fed-batch being carried out using a feed medium under conditions: • agitation between 100 and 1,000 rpm, and • temperature between 20 and 35°C, said feed medium being added at a flow rate, in particular at a constant flow rate, of between 0.01 and 0.50 gg^ose equivalents / g of biomass / h for a period of between 6 and 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 MgSO4, • from 50 to 500 gg^ose equivalents / 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 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 being optionally treated enzymatically, and • from 0 to 15 g / L of inactivated microorganism extract, 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, 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 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 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, collected debittered 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 0.5 to 30 min, at a temperature of 50 to 80°C; and possibly grinding of said debittered yeast powder, collected, optionally washed, inactivated and dried to obtain a powder of debittered yeasts, collected, optionally washed, inactivated, dried and optionally ground having a median particle size of 5 to 25 μm, said powder of debittered yeasts, 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.

8. Method according to claim 7, wherein said culturing step a.ii) is carried out under pO2 conditions of 0 to 100%, in particular 20 to 60% and more particularly 35 to 45%, and / or, wherein said fed-batch step a.iii) is carried out under pO2 conditions of 0 to 100%, in particular 20 to 60% and more particularly 35 to 45%, and / or, wherein 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. e) of inoculation or ai) of culturing at least, a 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 eliminating said supernatant, to obtain a brewing yeast drawn off, sedimented and concentrated from 10 to 25% in dry matter, said percentage in 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 the 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. A method according to any one of claims 7 to 10, wherein said brewing yeast from brewing fermentation comprises: • 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 0.2 to 4 mg of beta acids / g of debittered yeasts, in particular from 0.3 to 0.6 mg of beta acids / g of debittered yeasts, said beta acids being in particular lupulone, adlupulone and colupulone.

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

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