Sourdough and its uses in baking and cheesemaking

Abstract

The present invention relates to a specific sourdough starter comprising at least one lactic acid bacterium of the species Pediococcus parvulus and at least one second lactic acid bacterium selected from Leuconostoc citreum, Pantoea agglomerans, and Bacillus subtilis, as well as its use in breadmaking and cheesemaking. In particular, the invention relates to a sourdough starter intended for use in both breadmaking and cheesemaking.

Description

Title of the invention: Sourdough and its uses in baking and cheesemaking. Technical field

[0001] The invention relates to the fields of baking and cheesemaking. The invention concerns a specific sourdough starter, as well as its use in breadmaking and cheesemaking. In particular, the invention relates to a sourdough starter intended for use both in baking and in cheesemaking. State of the art

[0002] Consumers want to return to healthier, simpler, more natural products, more in line with their desire for autonomy and transparency, including in the food sector. Thus, consumer expectations can be summarized as: eating healthily and knowing what they are eating.

[0003] In this context, the inventor focused his interest on basic human food products known for millennia, namely bread and cheese. The manufacturing process of both has been revolutionized by the advent of industrial yeasts and rennets combined with heat treatments during the manufacturing process, making it possible to kill all microorganisms, including those beneficial to the body.

[0004] There is therefore a need to rediscover the products of yesteryear and the flavors of the past. In this context, the inventor became interested in a natural product at the origin of bread, known for millennia, namely sourdough.

[0005] Sourdough is a fermented dough obtained from flour and water, known for millennia and used in the preparation of bread, a staple food for humans. In particular, sourdough comprises a multitude of bacteria and yeasts acting in symbiosis within this highly complex environment.

[0006] This is composed primarily of wild yeasts and bacteria, mainly of the Lactobacillus genus. This particular symbiotic culture, unique to each sourdough starter, allows for the production of a specific type of bread with numerous health benefits. We can therefore distinguish between sourdough bread, which is making a strong comeback in our bakeries, and industrial bread made from yeast. Baker's yeast acts through alcoholic fermentation, unlike sourdough, which acts through lactic fermentation.

[0007] This difference gives sourdough bread numerous advantages over its counterpart. Indeed, it is easier to digest, due to the action of microorganisms that multiply within the sourdough starter and have a predigestion effect, facilitating its Digestion by our body. Some bacteria feed on starch, further facilitating its assimilation, but also lowering the glycemic index of bread and thus limiting the storage of carbohydrates by the body. Others can also break down gliadins, a component of gluten, again facilitating its assimilation, particularly for people with gluten intolerance.

[0008] Finally, the shelf life is increased, given the presence of bacteria that limit colonization by other bacteria. The presence of natural ferments also promotes the development of acidic and fruity aromatic notes in the bread and helps to recapture the flavors of yesteryear.

[0009] However, the majority of bakeries preparing sourdough bread use fermentable sourdough starter, that is to say, a mixture of highly concentrated industrial yeast and devitalized sourdough starter present solely for its flavor. This type of starter is killed by heat, inactivated, thus preventing any fermentation, and therefore the beneficial properties of sourdough bread. We can also mention dehydrated powdered sourdough starter, which is again a devitalized starter, resulting from fermentation, certainly, but dried and therefore preventing any further fermentation, particularly during kneading, etc. Thus, only a few rare bakers are reviving the bread of yesteryear, using a true sourdough starter maintained for years in their bakery.

[0010] In this context, the inventor, also faced with the need to rediscover cheeses with the flavors of yesteryear, without using rennet, discovered a particular starter that made it possible to prepare both bread and cheese while overcoming the disadvantages mentioned above.

[0011] To the best of our knowledge of the prior art, no sourdough starter exists that is suitable for preparing traditional sourdough bread and cheese. This is made possible by the particular and specific properties of the sourdough starter developed by the inventor. Furthermore, this specific sourdough starter is ready for use in less than 24 hours and requires only one feeding. Thus, it avoids the drawbacks associated with the use of commercial yeast, fermentable sourdough starter, or rennet, while also limiting the disadvantages of a traditional sourdough starter that requires regular feeding by the baker and is therefore not suitable for the entire profession. Summary of the invention

[0012] Thus, the invention relates to a sourdough starter comprising at least two lactic acid bacteria, a first bacterium belonging to the species Pediococcus parvulus and at least a second bacterium chosen from among a bacterium belonging to the species Leuconostoc citreum, Pantoea agglomerates, Bacillus subtilis, and their combination.

[0013] Preferably, the starter comprises a first bacterium belonging to the species Pediococcus parvulus and a second bacterium belonging to the species Leuconostoc citreum.

[0014] According to a preferred object of the invention, the starter comprises a bacterium of the species Pediococcus parvulus, a bacterium selected from the species Leuconostoc citreum, Pantoea agglomerans, and Bacillus subtilis, preferably the species Leuconostoc citreum, as well as at least two other bacteria selected from Pantoea agglomerans, Bacillus subtilis, Weissella cibaria, Lactococcus lactis, and their combination.

[0015] When the starter comprises a bacterium of the species Pediococcus parvulus, a bacterium of the species Leuconostoc citreum, and at least two other bacteria, these are very preferentially of the species Pantoea agglomerans, and of the species Bacillus subtilis.

[0016] According to another particularly preferred object of the invention, the starter also comprises at least one yeast selected from Saccharomyces barnettii and Saccharomyces cerevisiae. More preferably, the starter comprises at least two yeasts, namely one yeast of the species Saccharomyces barnettii and one yeast of the species Saccharomyces cerevisiae.

[0017] When the sourdough starter includes a yeast of the species Saccharomyces barnettii and a yeast of the species Saccharomyces cerevisiae, the quantity of Saccharomyces barnettii is advantageously greater than that of Saccharomyces cerevisiae, unlike the traditional and known sourdough starter which includes a majority of yeast of the species Saccharomyces cerevisiae.

[0018] According to another object of particular interest in the context of the invention, the species Pediococcus parvulus represents at least 80%, by weight, of the total weight of the sourdough starter, preferably 90%. Such an abundance is unique and not found in other sourdough starters, allowing for this specificity and its use in producing both baked goods and cheese products. The sourdough starter according to the invention thus makes it possible to replace the starters routinely used to prepare products in the cheese industry.

[0019] According to one object of the invention, the quantity of lactic acid bacteria in the sourdough starter of the invention is preferably at least 50x106 CFU of bacteria per gram (CFU / g).

[0020] According to another object, the quantity of yeast in the sourdough of the invention is preferably at least 5xl06 of yeast CFU per gram (CFU / g).

[0021] The sourdough according to the invention can be in several forms, advantageously the sourdough is in liquid or dry form.

[0022] Preferably, when the sourdough starter is in dry form, it can be rehydrated. Advantageously, the sourdough starter is rehydrated with a mixture comprising water and flour, thereby refreshing the starter. According to one embodiment, the sourdough starter is rehydrated with milk. Thus, according to another embodiment, the sourdough starter can be in the form of rehydrated form.

[0023] The sourdough starter therefore comprises a mixture of bacteria, in particular lactic acid bacteria, as well as yeasts. This flora, composed of specific microorganisms with specific abundances, is of particular interest in the context of the invention. Preferably, the lactic acid bacteria and / or yeasts constituting the sourdough starter according to the invention are in live, and / or semi-live, and / or attenuated, and / or inactivated form.

[0024] This very specific sourdough starter according to the invention is advantageously intended for preparing bakery and / or cheese products, thus overcoming the drawbacks of the prior art. Indeed, no sourdough starter is known that allows for the preparation of both bakery and cheese products. Therefore, according to another aspect, the sourdough starter according to the invention is intended to be used as a bread starter and / or a lactic starter.

[0025] According to one variant, the invention also relates to the use of the sourdough according to the invention in the preparation of a sourdough dough for bakery products or in the preparation of a baked bakery product or in the preparation of a cheese product.

[0026] Other features and advantages will become apparent from the detailed description of the invention, the examples and figures that follow. Detailed description of the invention

[0027] Definition

[0028] For the purposes of this invention, "starter" means a flour-based culture medium containing at least one cereal flour and water, or, alternatively, milk, said medium being inoculated and fermented by a selection of specific microorganisms. In the context of this invention, the selection of specific microorganisms comprises at least one bacterium of the species Pediococcus parvulus and a second bacterium selected from among the species Leuconostoc citreum, Pantoea agglomerans, and Bacillus subtilis.

[0029] By "refreshing the sourdough starter" or "refreshed" in the sense of the invention, we mean a new supply of flour and water to the sourdough starter or possibly milk, allowing to provide a new supply to the microorganisms contained in the sourdough starter.

[0030] For the purposes of this invention, "bread starter" refers to a starter intended for the production of a bakery product such as bread, brioche, or pastries. The terms "breadmaking" or "bakery" should be interpreted broadly in the context of this invention as referring to the fields of breadmaking and pastry making, and generally to the field of producing baked goods from fermented doughs based on flour.

[0031] For the purposes of this invention, "lactic starter" or "dairy starter" refers to a starter intended for the manufacture of a cheese product, such as cheese or yogurt. The term "dairy" or "lactic" should be interpreted broadly, in the context of this invention, as referring to the cheese-making industry and, more generally, to the production of coagulated dairy products (from cows, goats, sheep, etc.).

[0032] Sourdough according to the invention

[0033] The present invention therefore relates to a sourdough starter, that is to say a culture medium based on flour and water comprising a flora of microorganisms, said flora comprising at least two lactic acid bacteria, a first bacterium belonging to the species Pediococcus parvulus and a second bacterium chosen from among a bacterium belonging to the species Leuconostoc citreum, Pantoea agglomerans, and Bacillus subtilis.

[0034] Pediococcus parvulus is a Gram-positive, anaerobic bacillus of the Lactobacillaceae family. It is a lactic acid bacterium, known to be responsible for the fermentation of cabbage from the fermentable sugars contained in fresh cabbage.

[0035] Leuconostoc citreum is a lactic acid bacterium, Gram positive of the family Leuconostocaceae, phenotypically close to Pediococcus bacteria.

[0036] Pantoea agglomerans is the best-known species, belonging to the Pantoea family, also known as Enterobacter agglomerans or Erwinia herbicola. It is a ubiquitous bacterium isolated from plants, seeds, fruits, etc.

[0037] Bacillus subtilis belongs to the Bacillaceae family, is Gram-positive. It is a ubiquitous bacterium usually found in soil.

[0038] Preferably, the starter comprises a first bacterium belonging to the species Pediococcus parvulus and a second bacterium belonging to the species Leuconostoc citreum.

[0039] The inventor also determined the abundance of bacteria in the sourdough starter and therefore their quantities in the starter. Thus, preferably, the species Pediococcus parvulus represents at least 80% by weight of the total weight of the starter, preferably 90%, more preferably 95%, and even more preferably 98%. Such an abundance is unique and not found in other sourdough starters, allowing for this specificity and its use in producing both baked goods and cheese products. The sourdough starter according to the invention thus makes it possible to replace the starters commonly used to prepare products in the cheese industry.

[0040] The presence of these specific lactic acid bacteria is of particular interest, allowing the use of the sourdough starter according to the invention to prepare bakery and cheese products, thus overcoming the drawbacks of the prior art. Indeed, no sourdough starter is known that allows for the preparation of both Bakery and cheese products, that is, baked goods or coagulated milk-based products. Surprisingly, such a starter culture, containing at least Pediococcus parvulus and Leuconostoc citreum, allows this.

[0041] Advantageously, the quantity of lactic acid bacteria in the sourdough starter of the invention is at least 1x106 CFU of bacteria per gram (CFU / g), more preferably at least 50x106 CFU of bacteria per gram (CFU / g).

[0042] The sourdough starter may advantageously include other microorganisms, for example bacteria and yeasts. Thus, according to another preferred object of the invention, the sourdough starter includes a bacterium of the species Pediococcus parvulus, a bacterium of the species Leuconostoc citreum, and at least two other bacteria chosen from Pantoea agglomerates, Bacillus subtilis, Weissella cibaria, Lactococcus lactis, and their combinations.

[0043] Weissella cibaria is a Gram-positive bacterium of the family Leuconostocaceae.

[0044] Lactococcus lactis is a homofermentative, gram-positive lactic acid bacterium, notably used for the manufacture of milk-based products.

[0045] When the starter comprises a bacterium of the species Pediococcus parvulus, a bacterium of the species Leuconostoc citreum, and at least two other bacteria, these are very preferentially bacteria of the species Pantoea agglomerates, and of the species Bacillus subtilis.

[0046] According to another particularly preferred object of the invention, the starter also comprises at least one yeast selected from Saccharomyces barnettii and Saccharomyces cerevisiae. More preferably, the starter comprises at least two yeasts, namely one yeast of the species Saccharomyces barnettii and one yeast of the species Saccharomyces cerevisiae.

[0047] Saccharomyces cerevisiae, also known as brewer's yeast or baker's yeast. Indeed, it is commonly used in the fermentation of beer, fermented products, and bread. It has enabled the industrialization of bakery products by replacing traditional sourdough bread.

[0048] In the context of the invention, and somewhat surprisingly, Saccharomyces cerevisiae, although present in the sourdough starter, is present in a smaller quantity than Saccharomyces barnettii. Thus, when the sourdough starter comprises one yeast of the species Saccharomyces barnettii and one yeast of the species Saccharomyces cerevisiae, the quantity of Saccharomyces barnettii is preferentially greater than that of Saccharomyces cerevisiae, unlike traditional sourdough starter. Again, the specificity of the yeasts and their respective abundances make the sourdough starter according to the invention very specific and different from all conventional sourdough starters, which allows its use both in the preparation of baked goods and in the preparation of cheese or dairy products.

[0049] Preferably, the quantity of yeast in the sourdough of the invention is preferably at least 1x106 CFU of yeast per gram (CFU / g), more preferably at least 5x106 CFU of yeast per gram (CFU / g).

[0050] According to another object of the invention, the sourdough according to the invention can be in all known forms, preferably the sourdough is in liquid or dry form, more preferably it is in dry form.

[0051] When the sourdough starter is in dry form, it is very preferentially rehydrated before use.

[0052] When the sourdough starter is intended to be used as a bread starter, it is very advantageously rehydrated with a mixture comprising water and flour, allowing the sourdough starter to be refreshed.

[0053] When the sourdough starter is intended to be used as a lactic starter, it is very advantageously rehydrated with milk, allowing the starter to be refreshed and the production of cheese products, for example cheese, to be initiated.

[0054] Thus, according to a particularly preferred object, the leaven is presented in rehydrated form, preferably in dry form intended to be rehydrated.

[0055] According to another object, the sourdough starter therefore comprises a mixture of bacteria, in particular lactic acid bacteria, as well as specific yeasts, making it possible to overcome the drawbacks of the prior art. This flora, composed of specific microorganisms with specific abundances, is of particular interest in the context of the invention.

[0056] In this context, the lactic acid bacteria and / or yeasts constituting the sourdough according to the invention are preferably in live form, and / or semi-live form, and / or attenuated form and / or inactivated form, regardless of the form of the sourdough (dry, liquid, rehydrated).

[0057] Thus, this very specific sourdough starter according to the invention is advantageously intended for preparing bakery and / or cheese products, which overcomes the drawbacks of the prior art. Indeed, no sourdough starter is known that allows for the preparation of both bakery and cheese products. Thus, according to another aspect, the sourdough starter according to the invention is intended to be used as a bread and / or lactic starter.

[0058] According to one variant, the invention also relates to the use of the sourdough according to the invention in the preparation of a sourdough dough for bakery products or in the preparation of a baked bakery product or in the preparation of cheese products.

[0059] Process

[0060] The sourdough starter can be prepared according to the knowledge of a person skilled in the art for making sourdough starter. According to one aspect of the invention, the manufacturing process may comprise the following steps: a. The preparation of a culture medium, preferably a mixture of water and flour, advantageously a cereal flour, for example wheat flour, b. The selection of microorganisms of interest, namely at least Pediococcus parvulus and one bacterium chosen from Leuconostoc citreum, Pantoea ag-glomerans, and Bacillus subtilis, preferentially, the selection also includes at least two yeasts, namely Saccharomyces bamettii and Saccharomyces cerevisiae. c. Inoculation of the culture medium prepared in step a) with the selection of microorganisms prepared in step b) d. Fermentation of the culture medium with microorganisms to obtain the starter according to the invention

[0061] Advantageously, the preparation process will include several refreshments, i.e., the addition of a mixture of water and flour to obtain an abundance of Pediococcus parvulus of at least 80% by weight of the total weight of the starter. It is understood that the fermentation of the culture medium continues until the fermentable sugars contained in the medium are exhausted by the selected microorganisms.

[0062] By way of example, a person skilled in the art considers that there is depletion of fermentable sugars contained in the medium when the content of fermentable sugars in the medium is less than 2g / kg.

[0063] The manufacturing process described above makes it possible to obtain a sourdough starter according to the invention. According to an alternative, the manufacturing process may optionally include the preparation of a culture medium from a mixture of milk and flour.

[0064] For prolonged preservation of the sourdough obtained, said sourdough is cooled and stored at a temperature equal to or less than 8°C, preferably equal to or less than 4°C.

[0065] The process may also include a drying step. Drying the sourdough starter allows it to be stored for a long time (several decades) without needing to be refreshed. It can be dried naturally by hand, for example, by spreading it in thin layers on a tray and then placing it in a drying chamber at a low or medium temperature (8 to 25°C). It can also be dried after extrusion: the sourdough starter is refreshed and then mixed with an equivalent weight of flour, in order to be extruded by machine, for example, using a pasta machine with a bronze die. The extrusion temperature is below 40°C (water or air cooling system). The extruded sourdough starter is then cut into flakes and dried at a low or medium temperature until it reaches less than 11% moisture.

[0066] The invention is now illustrated by non-limiting examples of compositions according to the invention and by results. Examples

[0067] Example 1 - Preparation of a sourdough starter according to the invention

[0068] Preparation of the sourdough starter

[0069] The sourdough starter can be prepared according to the manufacturing process comprising the following steps: a. The preparation of the culture medium, comprising a mixture of water and wheat flour in a ratio of approximately 50 / 50, b. The selection of the following microorganisms, namely a strain of the species Pediococcus parvulus, a strain of the species Leuconostoc citreum, a strain of the species Pantoea agglomerons, and a strain of the species Bacillus subtilis, as well as two yeasts, namely Saccharomyces bamettii and Saccharomyces cerevisiae, the strain of the species Pediococcus parvulus being very predominant compared to the other strains, at least 60%. c. Inoculating the culture medium prepared in step a) with the selection of microorganisms prepared in step b), d. Fermentation of the culture medium for 48 to 30°C, with stirring every 24 hours, using microorganisms to obtain the starter according to the invention

[0070] The culture medium is prepared in a fermenter, into which water and wheat flour are added in a 50 / 50 ratio.

[0071] To this wheat flour-based culture medium, the selected microorganisms of interest are added in lyophilized form.

[0072] The mixture is left to ferment at 30°C for 24 hours under moderate stirring (150 RPM) without aeration. After 24 hours, the pH is adjusted to between 4 and 5 to accelerate the consumption of fermentable sugars. Fermentation continues for another 24 hours at 30°C.

[0073] The absence of directly fermentable sugars in the sourdough starter can be verified by HPLC analysis. The abundance of Pediococcus parvulus can be verified by the NGS method. If the abundance of Pediococcus parvulus is at least 80%, the sourdough starter is cooled to a temperature of approximately 4°C and maintained at 4°C. The sourdough starter is thus kept at this temperature without stirring.

[0074] NGS identification results of bacterial flora

[0075] The objective of this test is to identify, by "Next Generation Sequencing" (NGS), all the species composing the major flora of the sample, the sourdough starter. This overall flora includes both culturable, non-culturable and non-viable bacteria.

[0076] From a representative portion of the sample, the total genomic DNA is Extracted and purified using a commercial kit according to the supplier's recommendations, the entire bacterial DNA was amplified by PCR targeting a large region of the ribosomal DNA. After a second purification, the amplicons were prepared for sequencing of approximately 100,000 strands on a Nanopore platform. Data analysis was performed using a bioinformatics solution incorporating the Centrifuge assignment software (https: / / ccb.jhu.edu / software / centrifuge / ) and a database containing NCBI data (https: / / www.ncbi.nlm.nih.gov / ) specifically filtered and cured for the identification of the predominant bacterial flora. This database currently represents 2,086 genera and 7,756 bacterial species.

[0077] This identification made it possible to identify Pediococcus parvulus as the predominant species in the sourdough starter, namely 86.4%, and Leuconostoc citreum, namely 8.1%. The percentages reflect the distribution of the sequences assigned to each bacterial species.

[0078] Example 2 - Preparation of sourdough bread using sourdough according to the invention

[0079] Example 2 is an example of sourdough bread made from ready-to-use sourdough starter the use according to the invention at a rate of 200g of sourdough for 1kg of flour and 700g of water, 19g of salt.

[0080] The bread is prepared according to the following process: 1. Prepare the sourdough starter 3 hours before baking or refresh the previously prepared sourdough starter at least once before use. 2. Pour 1 kg of flour into a bowl, 3. In another bowl, pour 700ml of water at room temperature (20°C). Add 200g of sourdough starter according to the invention and mix until you obtain a smooth liquid. 4. Pour in the mixture from step 3 (starter + water) and mix the dough. 5. Let it rest for 2 minutes. 6. Add 20g of salt, and fold the dough. Let the salt dissolve in the dough for 1 minute. 7. Retrieve the dough previously obtained in step 6 and knead for 3 minutes. 8. Let the dough rest for 2 minutes. 9. Knead again for 3 minutes and adjust the amount of flour little by little until the dough is smooth and no longer sticks to your hands. 10. Let the dough rest for 3 hours at room temperature uncovered, folding it at least once an hour. 11. Cover the dough and let it rest for at least 3 more hours and up to a maximum of 6 hours at room temperature. 12. Shape the bread according to the desired form (baguette, boule, couronne...), Let the dough rest again for 30 minutes while the oven heats up (250° for 10 minutes) and bake at 225° for approximately 45 minutes.

[0081] Example 3 - Preparation of a cheese based on sourdough according to the invention

[0082] Example 3 describes a cheese obtained from the sourdough starter according to the invention. The steps The preparation process is as follows: a. A Jl: i. Preparation of the semi-liquid sourdough starter: 4.5 kg of flakes + 18 kg of flour + 18 kg of water at room temperature ii. Rehydration for 24 to 48 hours b. A J0 i. Add 270 litres to a GOAVEC tank and (1 x 45kg) to 1 mini-tank ii. Preparation of the sourdough starter: 1. Heat the milk in the mini-tank to 32°C 2. Adding the sourdough starter in rehydrated form (at a rate of 200g / liter of milk) in the mini-tank 1 3. Maturation for 3-4 hours at 32°C with gentle stirring 4. Filtering the sourdough starter while the milk is heating in the GOAVEC vat iii. Preparation of milk (culture medium): 1. Warming the milk to 38°C 2. Transfer into 2 x 501-liter containers in 2 PM bins 3. Inoculation with powdered or semi-liquid sourdough starter into each of the PM vats 4. Mix until completely dissolved 5. Maintaining the tanks at target temperatures of 38 to 40°C (room temperature regulation) until a pH of 4.8 is reached (12 to 24 hours) iv. Tank 1 will be used to make soft pasta (PM): 1. Curd removal, rest for 5 minutes, stirring, rest for 5 minutes, whey removal, stirring, bagging, draining until an EST of 40% v. Tank 2 will be used to make cooked pressed pasta (PPC): 1. Curd cutting, rest for 5 minutes, stirring, rest for 5 minutes, stirring, whey removal, stirring while heating the curd to 40-55°C, rest for 5 minutes, stirring, rest for 5 minutes, stirring, bagging, pressing with light weights, draining to an EST of 50% c. On day J+l, for productions 1 and 2: i. Unmolding of the bag, salting at 1% in mass, shaping in molds ii. Light surface salting üi. At +4h, turn the cheeses iv. Light surface salting v. Drying d. On day J+2, for batches 1 and 2: i. Unmolding the cheeses ii. Drying for 24 hours at 13°C (air sweep speed 5ms-l) e. A J+3 i. Maturation in a ripening room f. On the following days: i. Cheese monitoring ii. Packaging of cheeses when the surface flora is satisfactory üi. Cooling of products to 4°C.

Claims

Demands

1. Sourdough comprising at least two lactic acid bacteria, a first bacterium of the species Pediococcus parvulus and at least a second bacterium chosen from a bacterium of the species Leuconostoc citreum, Pantoea agglomerons, and Bacillus subtilis.

2. Sourdough according to the preceding claim, characterized in that the sourdough comprises Pediococcus parvulus and Leuconostoc citreum, and at least two other bacteria selected from Pantoea agglomerates, Bacillus subtilis, Weissella cibaria, and Lactococcus lactis.

3. Leaven according to any one of the preceding claims, characterized in that the leaven comprises at least Pediococcus parvulus, Leuconostoc citreum, Pantoea agglomerans and Bacillus subtilis.

4. Sourdough according to any one of the preceding claims, characterized in that the sourdough also comprises at least one yeast selected from Saccharomyces bamettii and Saccharomyces cerevisiae.

5. Sourdough according to the preceding claim, characterized in that the quantity of Saccharomyces bamettii is greater than that of Saccharomyces cerevisiae, in weight of the total weight of the sourdough.

6. Sourdough according to any one of the preceding claims, characterized in that the bacterium of the species Pediococcus parvulus represents at least 80%, by weight of the total weight of the sourdough, preferably 90%.

7. Sourdough according to any one of the preceding claims, characterized in that the quantity of lactic acid bacteria in said sourdough is at least 50x106 CFU of bacteria per gram (CFU / g).

8. Sourdough according to any one of claims 4 to 7, characterized in that the quantity of yeast in said sourdough is at least 5xl06 of yeast CFU per gram (CFU / g).

9. Sourdough according to any one of the preceding claims, characterized in that the sourdough is in liquid or dry form.

10. Sourdough according to any one of the preceding claims, characterized in that the lactic acid bacteria and / or yeasts are in live, semi-live, attenuated or inactivated form

11. Sourdough according to any one of the preceding claims, characterized in that the sourdough is in rehydrated form.

12. Sourdough according to any one of the preceding claims, characterized in that the sourdough is intended to be used as bread sourdough and / or lactic sourdough.

13. Use of a sourdough according to one of the preceding claims in the preparation of a sourdough dough for bakery products or in the preparation of a baked bakery product or in the preparation of a cheese product.