Stable liquid sourdough products

Abstract

The present application provides methods for preparing a liquid sourdough product comprising: a) adding amyloglucosidase to a liquid mixture comprising cereal(s) and / or cereal fractions; b) inoculating the liquid mixture with one or more strains of Weissella confusa; c) fermenting the liquid mixture obtained in step b) for a period between 4 and 8 hours at a temperature between 15.0 and 40.0°C; d) adding at least 5.0 % (w / w) of sugar to the fermented liquid mixture obtained in step c); and e) further fermenting the fermented liquid mixture obtained in step d) at a temperature between 15.0 and 40.0°C for a period between 18 and 48 hours, thereby obtaining a liquid sourdough product. The application further provides stable liquid sourdough products obtained by such methods and uses thereof.

Description

[0001] STABLE LIQUID SOURDOUGH PRODUCTS

[0002] FIELD OF THE INVENTION

[0003] The present invention provides stable liquid sourdough products and methods for improving the stability of liquid sourdoughs. More specifically it provides sourdough products obtained through the fermentation of cereals by specific strains of bacteria. More particularly, the sourdough products may be clean label.

[0004] BACKGROUND OF THE INVENTION

[0005] Bread is an important part of the diet in many countries and represents one of the most consumed fermented foods in the world. Using sourdough is one of the oldest ways of traditional and artisanal bread leavening. Sourdoughs are alternatives to baker's yeast and chemical leavening. Compared to products fermented by yeast alone, the sourdough baked goods have a longer shelf life, due to antifungal compounds and bacteriocin production and higher acidity, a higher sensory quality due to increased elasticity, internal humidity, and volatile compound concentration, and a greater nutritional value due to reduction of anti-nutritional compounds such as phytate.

[0006] Sourdough is defined as a dough of flour and water fermented by lactic acid bacteria (LAB) optionally in combination with yeast, used as a leavening agent for the production of bakery products. Sourdough was initially obtained from the spontaneous fermentation of microorganisms present in the flour or in other raw materials. The spontaneous fermentation (only flour and water) takes nearly one week and at the end the most frequently identified lactic acid bacteria are Fructilactobacillus sanfranciscensis (formerly known as Lactobacillus sanfranciscensis), Lactiplantibacillus plantarum (formerly known as Lactobacillus plantarum) and Weissella cibaria, in conjunction with the yeasts Saccharomyces cerevisiae, Kazachstania exigua, and Candida humilis.

[0007] Three types of sourdoughs are generally recognized. Traditional sourdoughs (Type I) are sourdoughs that are restarted using a part of the previous fermented dough which is therefore constantly renewed in a cyclical way, using specific recipes and ripening conditions. The mother dough is then mixed with rest of the flour, water, salt and fat to a suitable consistency, and then given a short period for fermentation before final proofing and baking. Active sourdoughs (Type II) are an improved type of sourdoughs using adapted strains or liquid sourdough starters to start the fermentation. These sourdoughs can be pasty or liquid and are generally stable and easy to process for example in an automated bakery. There are enough living lactic acid bacteria and / or yeast to ferment a bread dough successfully or to initiate a multiple stage sourdough process. Finally inactive powder or liquid sourdoughs (Type III) are used by traditional or industrial bakeries for their convenience since the quality is constant and they are easy to use. These will deliver the acidity and the conventional sourdough flavour directly avoiding a long fermentation step.

[0008] In the industrial production of Type II sourdoughs or Type III liquid sourdoughs the amount of flour is generally low in order to keep the sourdough pumpable. The ratio of flour to water determines the thickness of the sourdough and can be expressed as dough yield (DY), that is defined as 100 parts of flour plus the amount of water (in parts) used for hydration. It can be liquid (DY 250 - 300), paste like (DY 150 - 250), or dough like (DY < 150). During the fermentation, the consistency of sourdough may further decrease due to enzymatic hydrolysis. Liquid sourdoughs (DY 250 - 300) are generally preferred by the bakery industry, because they are pumpable but not too watery for dough making. Furthermore, to be able to produce Type II sourdoughs or Type III liquid sourdoughs in a fermenter on an industrial line such high dough yield is also needed to allow handling ( pumpability). Working with dough yield between 250 and 300 results in some issues during the storage of the sourdough. Indeed syneresis may occur due to decantation and consequently a water layer appears on the top of the liquid fermented sourdough. This is inconvenient as it requires mixing of the product during storage and / or before use. To avoid the syneresis in industrial batches of Type II sourdough or Type III liquid sourdoughs, one may add hydrocolloids such as xanthan gum. Such ingredients are considered as additives and need to be indicated as such on the product label.

[0009] However, the food industry is currently being driven by consumers to become more transparent about the used ingredients. Also, consumers prefer foods without additives as these are considered "healthier".

[0010] Therefore there is still a need to provide products, such as stable Type II sourdoughs, that do not contain additives ("clean label" products). It is the aim of the present invention to provide sourdough products with improved properties such as improved stability. SUMMARY OF THE INVENTION

[0011] The present inventors have developed methods for improving liquid sourdough products and more particularly for improving the level of decantation of liquid sourdough products. More particularly, present inventors found to their surprise that the level of decantation, and consequently the syneresis, of a liquid sourdough product, such as a Type II sourdough or Type III liquid sourdough, can be reduced without requiring the use of additives such as hydrocolloids and / or gums by fermenting a liquid mixture comprising cereal(s) and / or cereal fractions, water and amyloglucosidase with one or more strains of Weissella confusa and by adding sugar, such as sucrose, during the exponential growth phase of said bacteria, and more particularly after 4 to 8 hours of fermentation of the liquid mixture. Notably, this timing of sugar addition leads to a superior reduction in decantation compared to processes in which the sugar is added prior to the start of fermentation. The result thereof is that "clean (er) label" liquid sourdough products can be obtained and that these liquid sourdough products are more stable upon storing, and do not need to be stored, for instance, in packages with internal mixing systems or on a shaker, to maintain the product's homogeneity. This also reduces the cost of producing liquid sourdough products and sourdough products overall. Present inventors have also shown that the incorporation of the liquid sourdough products of the present invention into a bakery or patisserie product does not alter the techno-functional properties of the sourdough.

[0012] Accordingly, a first aspect provides a method for preparing a liquid sourdough product comprising the steps of: a) adding amyloglucosidase to a liquid mixture comprising cereal(s) and / or cereal fractions and water, wherein said liquid mixture has a dough yield between 150 and 500 and wherein said amyloglucosidase is added to said liquid mixture in an amount between 20 and 500 Amyloglucosidase Units (AU) / 100 g of said liquid mixture; b) inoculating the liquid mixture obtained in step a) with one or more strains of Weissella confusa at a concentration of between 105and 109living cells / g of liquid mixture; c) fermenting the liquid mixture obtained in step b) for a period between 4 and 8 hours at a temperature between 15.0 and 40.0°C; d) adding between 5.0 and 20.0 % (w / w) of sugar to the fermented liquid mixture obtained in step c); and e) further fermenting the fermented liquid mixture obtained in step d) at a temperature between 15.0 and 40.0°C for a period between 18 and 48 hours, thereby obtaining a liquid sourdough product.

[0013] In a particular embodiment, said liquid mixture is fermented in steps c) and / or e) (and optionally d)) by one or more microorganisms in addition to the one or more strains of Weissella confusa, wherein said microorganisms are chosen from a lactic acid bacteria strain and / or a yeast strain, preferably wherein the lactic acid bacteria strain is a strain of Lactobacillus and / or the yeast strain is a strain of Saccharomyces or Kazachstania.

[0014] In a particular embodiment, said sugar comprises sucrose.

[0015] In a particular embodiment, the method further comprises a step of inactivating the one or more strains of Weissella confusa and optionally the one or more microorganisms in addition to the one or more strains of Weissella confusa, wherein said step is performed after step e) (or step c2).

[0016] In a particular embodiment, the method further comprises a step of cooling and / or packing the liquid sourdough product.

[0017] In a further aspect, the present application relates to a liquid sourdough product comprising cereal(s) and / or cereal fractions, wherein said liquid sourdough product is fermented by one or more strains of Weissella confusa; and wherein the level of decantation of said liquid sourdough product is less than 5% after 24 hours storage at a temperature between 4.0°C and 30.0°C.

[0018] In a particular embodiment, the liquid sourdough product, as described herein, comprises less than 0.50 % of gums and / or hydrocolloids.

[0019] In a particular embodiment, the liquid sourdough product, as described herein, wherein said liquid sourdough product has a pH between 5.0 and 2.5, more preferably between 4.5 and 3.0.

[0020] In a particular embodiment, the liquid sourdough product, as described herein, wherein said sourdough product is an active or inactive sourdough product.

[0021] In a particular embodiment, the method, as described herein, or the liquid sourdough product as described herein, wherein said one or more strains of Weissella confusa comprise Weissella confusa LMG S-33544.

[0022] In a further aspect, the present application relates to a liquid sourdough product, wherein said liquid sourdough product is obtained or obtainable by the method as described herein. In a further aspect, the present application relates to the use of the liquid sourdough product as described herein, as an ingredient of a food product, preferably a bakery or patisserie product.

[0023] In a further aspect, the present application relates to a method of preparing a food product, preferably a bakery or patisserie product, comprising admixing the liquid sourdough product as described herein, and one or more additional ingredients.

[0024] In a further aspect, the present application relates to a food product comprising the liquid sourdough product as described herein.

[0025] In a particular embodiment, the food product is a bakery or patisserie product.

[0026] DETAILED DESCRIPTION OF THE INVENTION

[0027] Before the present method and devices used in the invention are described, it is to be understood that this invention is not limited to particular compositions, components, uses, or methods, described as such compositions, components, uses, or methods, may, of course, vary. It is also to be understood that the terminology used herein is not intended to be limiting, since the scope of the present invention will be limited only by the appended claims.

[0028] As used herein, the singular forms "a", "an", and "the" include both singular and plural referents unless the context clearly dictates otherwise.

[0029] The terms "comprising", "comprises" and "comprised of" as used herein are synonymous with "including", "includes", "containing", or "contains", and are inclusive or open-ended and do not exclude additional, non-recited members, elements or method steps. The terms also encompass "constituted of", "consists in", "consisting of", and "consists of", and also the terms "consisting essentially of", "consisting essentially in" and "consists essentially of", which enjoy well- established meanings in patent terminology.

[0030] The recitation of numerical ranges by endpoints includes all intervening values between the lower and upper endpoints, as well as the recited endpoints. Intervening values may be integers or, where applicable, fractions, i.e., more broadly any real numbers such as any rational numbers. This applies to numerical ranges irrespective of whether they are introduced by the expression "from... to..." or the expression "between... and..." or another expression. Any numerical range recited herein is intended to include all sub-ranges subsumed therein. For example, each sub-range between any stated value in a stated range and any other stated value in that stated range is also specifically disclosed. Each sub-range between any stated value in a stated range and either the lower endpoint or the upper endpoint of the stated range is also specifically disclosed. The stated value may be an isolated value or an endpoint of a range subsumed by or overlapping with the stated range. For example, for a stated range with lower endpoint LI and upper endpoint U1 (i.e., stated range Ll-Ul) and a stated sub-range nested within the stated range with lower endpoint L2 and upper endpoint U2 (i.e., stated sub-range L2-U2), also specifically disclosed are the subranges L1-L2, L1-U2, L2-U1, and U2-U1.

[0031] The terms "about" or "approximately" as used herein when referring to a measurable value such as a parameter, an amount, a temporal duration, and the like, are meant to encompass variations of and from the specified value, such as variations of + / -10% or less, preferably + / -5% or less, more preferably + / -1% or less, and still more preferably + / -0.1% or less of and from the specified value, insofar such variations are appropriate to perform in the disclosed invention. It is to be understood that the value to which the modifier "about" or "approximately" refers is itself also specifically, and preferably, disclosed.

[0032] Furthermore, the terms first, second, third and the like in the description and in the claims, are used for distinguishing between similar elements and not necessarily for describing a sequential or chronological order, unless specified. It is to be understood that the terms so used are interchangeable under appropriate circumstances and that the embodiments of the invention described herein are capable of operation in other sequences than described or illustrated herein.

[0033] Whereas the terms "one or more" or "at least one", such as one or more members or at least one member of a group of members, is clear per se, by means of further exemplification, the term encompasses inter alia a reference to any one of said members, or to any two or more of said members, such as, e.g., any >3, >4, >5, >6 or >7 etc. of said members, and up to all said members. In another example, "one or more" or "at least one" may refer to 1, 2, 3, 4, 5, 6, 7 or more.

[0034] As used herein, the term "and / or" when used in a list of two or more items, means that any one of the listed items can be employed by itself or any combination of two or more of the listed items can be employed. For example, if a list is described as comprising group A, B, and / or C, the list can comprise A alone, B alone, C alone, A and B in combination, A and C in combination, B and C in combination, or A, B, and C in combination.

[0035] The discussion of the background to the invention herein is included to explain the context of the invention. This is not to be taken as an admission that any of the material referred to was published, known, or part of the common general knowledge in any country as of the priority date of any of the claims.

[0036] Throughout this disclosure, various publications, patents and published patent specifications are referenced by an identifying citation. All documents cited in the present specification are hereby incorporated by reference in their entirety. In particular, the teachings or sections of such documents herein specifically referred to are incorporated by reference.

[0037] Unless otherwise defined, all terms used in disclosing the invention, including technical and scientific terms, have the meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. By means of further guidance, term definitions are included to better appreciate the teaching of the invention. When specific terms are defined in connection with a particular aspect of the invention or a particular embodiment of the invention, such connotation or meaning is meant to apply throughout this specification, i.e., also in the context of other aspects or embodiments of the invention, unless otherwise defined.

[0038] In the following passages, different aspects or embodiments of the invention are defined in more detail. Each aspect or embodiment so defined may be combined with any other aspect(s) or embodiment(s) unless clearly indicated to the contrary. In particular, any feature indicated as being preferred or advantageous may be combined with any other feature or features indicated as being preferred or advantageous.

[0039] Reference throughout this specification to "one embodiment", "an embodiment" means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrases "in one embodiment" or "in an embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment, but may. Furthermore, the particular features, structures or characteristics may be combined in any suitable manner, as would be apparent to a person skilled in the art from this disclosure, in one or more embodiments. Furthermore, while some embodiments described herein include some but not other features included in other embodiments, combinations of features of different embodiments are meant to be within the scope of the invention, and form different embodiments, as would be understood by those in the art. For example, in the appended claims, any of the claimed embodiments can be used in any combination.

[0040] Similarly, it should be appreciated that in the description of illustrative embodiments of the invention, various features of the invention are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure and aiding in the understanding of one or more of the various inventive aspects.

[0041] Unless referred to herein otherwise the percentages as mentioned herein refer to percentages by weight.

[0042] The present inventors have surprisingly found that it was possible to improve the stability of liquid sourdough products by using specific lactic acid bacteria, more particularly Weissella confusa, even in the absence of additives, such as hydrocolloids and / or gums combined with a specific fermentation process. In the context of the present invention, the sourdough product stability refers to its capacity to not decant during a certain period of time of storage, such as one week of storage or even such as one month of storage or even more.

[0043] It is therefore a first object of the present invention to provide a method for preparing a liquid sourdough product that comprises the steps of: a) adding amyloglucosidase to a liquid mixture comprising cereal(s) and / or cereal fractions and water, wherein said liquid mixture has a dough yield between 150 and 500 and wherein said amyloglucosidase is added to said liquid mixture in an amount between 20 and 500 Amyloglucosidase Units (AU) / 100 g of said liquid mixture; b) inoculating the liquid mixture obtained in step a) (i.e. the liquid mixture comprising amyloglucosidase) with one or more strains of Weissella confusa at a concentration of between 105and 109living cells / g of liquid mixture, preferably between 107and 108living cells / g of liquid mixture; c) ("cl") fermenting the liquid mixture obtained in step b) for a period between 4 and 8 hours at a temperature between 15.0°C and 40.0°C, preferably between 15.0°C and 30.0°C, more preferably between 15.0°C and 25.0°C (thereby obtaining a first (partly) fermented liquid mixture); d) adding at least 5.0% (w / w), preferably between 5.0 and 20.0 % (w / w) of sugar, more preferably between 5.0 and 15.0% (w / w), of sugar, preferably sucrose, to the fermented liquid mixture obtained in step c) ("cl") (i.e. to the first (partly) fermented liquid mixture) (thereby obtaining a sugared fermented liquid mixture); and e) further fermenting the fermented liquid mixture obtained in step d) (i.e. the sugared fermented liquid mixture) at a temperature between 15.0°C and 40.0°C, preferably between 15.0°C and 30.0°C, more preferably between 15.0°C and 25.0°C for a period between 18 and 48 hours, thereby obtaining a liquid sourdough product (i.e. the second fermented liquid mixture).

[0044] This method can also be a method for improving the level of decantation of a liquid sourdough product.

[0045] The term "cereal", in the context of the present invention, refers to the edible components of plants of the botanical family of the Poaceae, including but not limited to species such as wheat, barley, oat, spelt, rye, sorghum, maize, triticale, millet, teff, and / or rice. Preferably, the cereals are chosen among the group of wheat, maize (corn), rice, rye, or a combination thereof. More preferred cereals are rye, rice, wheat, or a combination thereof. An even more preferred cereal is wheat or rye, even more preferably wheat.

[0046] The term "cereal fraction", in the context of the present invention, refers to all or part of the fractions resulting from mechanical reduction of the size of grains, through, for example, but not limited thereto, cutting, rolling, crushing, breakage or milling, with or without fractionation, through, for example, but not limited thereto, sieving, screening, sifting, blowing, aspirating, centrifugal sifting, wind sifting, electrostatic separation, or electric field separation. Preferred cereal fractions are flours, whole flours, brans and / or any combination thereof.

[0047] In particular embodiments, the cereal(s) and / or cereal fractions comprise, consist essentially of or consist of wheat flour or rye flour.

[0048] In particular embodiments, the cereal(s) and / or cereal fractions are firstly suspended in a suitable liquid, preferably water, thereby obtaining a (liquid) mixture comprising cereal(s) and / or cereal fractions and water. The liquid mixture comprising cereal(s) and / or cereal fractions and water is characterized by having a dough yield between 150 and 500 or between 150 and 400, preferably between 200 and 350, such as between 200 and 300 or between 250 and 300. In the context of the present invention, the dough yield is defined as being 100 parts of flour plus the amount of water (in parts) used for hydration. Alternatively the mixture may be characterized by its dry matter. The dry matter of the mixture is preferably between 20% and 70%, more preferably between 30% and 50%.

[0049] The term "amyloglucosidase", in the context of the present invention refers to an enzyme that hydrolyses the terminal ( 1— >4)-l i n ked a-D-glucose residues successively from non-reducing ends of glucose chains with release of p-D-glucose. Amyloglucosidase is characterized by Enzyme Commission (EC) number 3.2.1.3 and is registered at the Chemical Abstracts Service (CAS) with CAS No. 9032-08-0 . Alternative names for amyloglucosidase include 4-a-D-glucan glucohydrolase, glucoamylase, etc. Examples of suitable amyloglucosidase include the glucoamylases of Talaromyces emersonii , Aspergillus niger , Trichoderma reesei and Rhizopus sp. Many methods may be used to determine the activity of the amyloglucosidase. One preferred method is the determination of the activity using p-Nitrophenyl-p-maltoside as substrate in the presence of p-glucosidase. Using this method, one Amyloglucosidase Unit (AU) is defined as the amount of enzyme which releases one pmole of p-nitrophenol from the substrate per minute at pH 4.5 and 40°C. The amyloglucosidase may be added in an amount between 20 and 500 Amyloglucosidase Units (AU) / 100 g of mixture, such as between 20 and 400 Amyloglucosidase Units (AU) / 100 g of mixture, preferably between 25 and 300 Amyloglucosidase Units (AU) / 100 g of mixture.

[0050] Bacteria of the genus Weissella confusa are Gram-positive, catalase-negative, non-endospore forming cells (short rods morphology). They belong to the group of bacteria generally known as lactic acid bacteria. Phylogenetically, Weissella belongs to the Firmicutes, class Bacilli, order Lactobacillales and family Leuconostocaceae. They are obligately heterofermentative, producing CO2 from carbohydrate metabolism with either D(-)-, or a mixture of D (-) - and L (+) - lactic acid and acetic acid as major end products from sugar metabolism. Ammonia results from arginine breakdown and acid is produced from cellobiose, galactose, ribose, salicin, sucrose and xylose, but not from arabinose, lactose, melibiose, raffinose and trehalose fermentation. Dextran is formed from sucrose. The mol% G+C content of the DNA is 45-47%.

[0051] In a particular embodiment of the method as taught herein, the strain of Weissella confusa is Weissella confusa LMG 9497.

[0052] In a particular embodiment of the method as taught herein, the strain of Weissella confusa is Weissella confusa LMG S-33544, deposited on 16 / 02 / 2024 at the BCCM / LMG Bacteria Collection, Laboratory of Microbiology, Ghent University; Belgium (e.g. see Table A).

[0053] Table A

[0054] In a particular embodiment the method as taught herein is characterized in that the liquid mixture is fermented in steps c) and / or e) by the addition of one or more strain of Weissella confusa, preferably Weissella confusa LMG S-33544, and one or more microorganisms in addition to the one or more strains of Weissella confusa, wherein said microorganisms are chosen from lactic acid forming bacteria and / or yeast strains. Accordingly, in particular embodiments, step b) may be inoculating the liquid mixture obtained in step a) with one or more strains of Weissella confusa at a concentration of between 105and 109living cells / g of liquid mixture and one or more inoculating the liquid mixture obtained in step a) with one or more strains of Weissella confusa at a concentration of between 105and 109living cells / g of liquid mixture. In embodiments, the one or more strains of lactic acid bacteria can be chosen from strains of Lactobacillus sp. In embodiments, the one or more strains of yeasts can be chosen from strains of Saccharomyces or Kazachstania sp.

[0055] In embodiments,, the one or more strains of Weissella confusa, preferably Weissella confusa LMG S-33544, and optionally one or more additional microorganisms chosen from lactic acid forming bacteria and / or yeast strains, can each be added in an amount between 105to 109living cells / g of mixture, preferably between 107and 108living cells / g of liquid mixture.

[0056] In a preferred embodiment, the living microorganisms or cells are added under the form of microorganisms or cells having been first cultivated in another culture medium to obtain a starter culture. When two or more bacterial species are used, the strains are preferably separately cultivated in another culture medium to obtain a starter culture, such as prior to inoculating the liquid mixture obtained in step a) with the microorganisms or cells. The liquid mixture containing cereal(s) and / or cereal fraction(s) and amyloglucosidase and inoculated with one or more strains of Weissella confusa, preferably Weissella confusa LMG S- 33544, and optionally one or more additional microorganisms chosen from lactic acid forming bacteria and / or yeast strains (e.g. as obtained in step b)), can be fermented in a first fermentation step cl) for a period of 4 to 15 hours, preferably for a period between 4 and 10 hours and more preferably between 4 and 8 hours, such as between 5 and 7 hours, at a temperature between 15.0 and 40.0°C, preferably between 15.0°C and 30.0°C, more preferably between 15.0°C and 25.0°C. Preferably, at the end of this first fermentation step the microorganisms and / or the cells are in their exponential growth phase.

[0057] After this first fermentation step (step cl)) sugar is added to the (partially)fermented liquid mixture (i.e. to first (partially) fermented liquid mixture). As a result thereof, a sugared fermented liquid mixture is obtained. Sugar typically encompasses monosaccharides (such as glucose, fructose, and galactose), disaccharides (such as sucrose, lactose, and maltose), and other saccharides. In a preferred embodiment, sugar comprises or consists of sucrose. In particular embodiments, at least 5.0% (w / w), at least 6.0% (w / w), at least 7.0% (w / ), at least 7.5%, at least 8.0% (w / w), at least 9.0% (w / w), or at least 10.0% (w / w) of sugar, preferably sucrose, is added in step c). In particular embodiments, between 5.0 and 30.0 % (w / w), between 5.0 and 20.0 % (w / w) of sugar, more preferably between 5.0 and 15.0% (w / w), such as between 7.0 and 12.0 % (w / w)., of sugar, preferably sucrose, is added in step c).

[0058] The sugared (partially) fermented liquid mixture is further fermented for a period between 12 and 150 hours, preferably between 18 and 48 hours, such as between 18 and 42 hours, between 18 and 36 hours, between 18 and 30 hours or between 18 and 24 hours, at a temperature between 15.0 and 40.0°C, preferably between 15.0°C and 30.0°C, more preferably between 15.0°C and 25.0°C, thereby obtaining a liquid sourdough product (i.e. second fermented liquid mixture). In some embodiments, the fermentation of step c) and / or e) can be stop when the pH of the liquid mixture and / or the fermented liquid mixture is below 4.5 or lowered to a pH below 4.5.

[0059] The total fermentation time (e.g. the sum of the fermentation time of steps c) and / or e), and optionally d)) may be between 16 and 175 hours, preferably between 20 and 100 hours, more preferably between 20 and 72 hours, such as between 20 and 66 hours, between 20 and 60 hours, between 20 and 54 hours, between 20 and 48 hours, between 20 and 42 hours, between 20 and 36 hours, between 20 and 30 hours, or between 22 and 30 hours. + In preferred embodiments, the fermentation is continued between the first fermentation (step cl) of the method as taught herein) and the second fermentation (step e) of the method as taught herein) and the sugar is being added while the "first" fermentation is still ongoing.

[0060] Accordingly, in particular embodiments, the method as taught herein comprises the steps of: a) adding amyloglucosidase to a liquid mixture comprising cereal(s) and / or cereal fractions and water, wherein said liquid mixture has a dough yield between 150 and 500 and wherein said amyloglucosidase is added to said liquid mixture in an amount between 20 and 500 Amyloglucosidase Units (AU) / 100 g of said liquid mixture; b) inoculating the liquid mixture obtained in step a) with one or more strains of Weissella confusa at a concentration of between 105and 109living cells / g of liquid mixture; c) ("c2") fermenting the liquid mixture obtained in step b) for a period between 22 and 56 hours at a temperature between 15.0 and 40.0°C; wherein between 5.0 and 20.0 % (w / w) of sugar, preferably sucrose, is added to the (partly) fermented liquid mixture 4 to 8 hours after the start of the fermentation, thereby obtaining a liquid sourdough product.

[0061] However, the fermentation could also be paused (such as for at most 15 minutes, at most 10 minutes, at most 5 minutes, or at most 1 minute) between the first fermentation (step cl) of the method as taught herein) and the second fermentation (step e) of the method as taught herein) to add the sugar to the first fermented liquid mixture.

[0062] In particular embodiments, the method as taught herein does not comprise the addition of (exogenous) sugar, such as sucrose, to the liquid mixture before the first fermentation step (i.e. before step c)). In particular embodiments, at most 5.0% (w / w), at most 4.0% (w / w), at most 3.0% (w / w), at most 2.0% (w / w), at most 1.0% (w / w), at most 0.5% (w / w), at most 0.1% (w / w), at most 0.05% (w / w) of (exogenous) sugar, such as sucrose, is being added to the liquid mixture before the first fermentation step (i.e. before step c) of the method as taught herein).

[0063] In embodiments, the fermenting steps c) and / or e) can be static or non-static fermentation steps. In embodiments, the fermenting steps c) and / or e) comprise agitation, such as rotation, of the liquid mixture and / or of the fermented liquid mixture.

[0064] In particular embodiments one or more of the additional microorganisms chosen from lactic acid forming bacteria and / or yeast strains may be added at any point during the fermentation in steps c) and / or e). As an example lactic acid bacteria such as Lactiplantibacillus plantarum may be added to further acidify and / or to improve the sensorial profile of the stable liquid sourdough product.

[0065] In embodiments, the method can further comprise a step of inactivating the one or more strains of Weissella confusa and optionally the one or more microorganisms in addition to the one or more strains of Weissella confusa, wherein said inactivation step is performed after step e) (or after step c2).

[0066] As referred to herein, the inactivation of the Weissella strain(s) and optionally the additional microorganisms, may be performed using conventional methods known in the art such as, but not limited to, heat inactivation or salt inactivation. In a preferred embodiment, salt can be added to the liquid mixture or to the liquid sourdough product to inactivate Weissella strain(s), preferably the salt comprises natrium chloride (NaCI), at a concentration between 10.0% and 25.0% (weight of salt / weight of liquid sourdough), preferably between 10.0% and 15.0%.

[0067] In particular embodiments, when the liquid sourdough product is not inactivated, it can be termed living liquid sourdough product and comprises preferably at least 107Weissella confusa living cells / g of living liquid sourdough product.ln particular embodiments of the method as taught herein, one or more additional ingredients may be added to the liquid mixture(s) (e.g. to the first fermented liquid mixture or to the sugared fermented liquid mixture or to the second fermented liquid mixture).

[0068] In particular embodiments of the method as taught herein, the optional additional ingredients of the liquid sourdough product may be chosen from the non-limiting list of yeast extract, salt(s), sugar(s), oxidant(s), reducer(s), enzyme(s), protein(s), fat(s) and combinations thereof.

[0069] After fermentation of step e) (or step c2) or optionally after the inactivation step, the liquid sourdough product may be packaged in any type of packaging that ensures the protection and the stability of the product. It is particularly advantageous that the method of the present invention provides liquid sourdough products with improved decantation levels, eliminating the need for packaging (such as containers) with internal mixing systems or those that require shaking to maintain homogeneity of the liquid sourdough product. This is further advantageous in the case of large packaging (such as 500 litres or 1000 litres containers) that are more difficult to handle and shake.

[0070] Another aspect of the invention relates to a method for improving the level of decantation of a sourdough product comprising: a) adding amyloglucosidase to a liquid mixture comprising cereal(s) and / or cereal fractions and water, wherein said liquid mixture has a dough yield between 150 and 500 and wherein said amyloglucosidase is added to said liquid mixture in an amount between 20 and 500 Amyloglucosidase Units (AU) / 100 g of said liquid mixture; b) inoculating the liquid mixture obtained in step a) with one or more strains of Weissella confuas, preferably Weissella confusa LMG S-33544, at a concentration of between 105and 109living cells / g of liquid mixture, preferably between 107and 108living cells / g of liquid mixture; c) fermenting the liquid mixture obtained in step b) for a period between 4 and 8 hours at a temperature between 15.0 and 40.0°C, preferably between 15.0°C and 30.0°C, more preferably between 15.0°C and 25.0°C; d) adding between 5.0 and 20.0 % (w / w) of sugar, preferably between 5.0 and 15.0% (w / w) of sugar, to the fermented liquid mixture obtained in step c); and e) further fermenting the fermented liquid mixture obtained in step d) at a temperature between 15.0 °C and 40.0°C, preferably between 15.0°C and 30.0°C, more preferably between 15.0°C and 25.0°C for a period between 18 and 48 hours, thereby obtaining a liquid sourdough product.

[0071] In embodiments, the level of decantation of said liquid sourdough product (such as the liquid sourdough product obtained in step e) (or step c2) of the method as taught herein) is less than 5.0%, preferably less than 2.0% and even more preferably 0.0%; after 24 hours storage, preferably after one week storage, more preferably after 1 month storage, such as after two months storage, and when stored at a temperature between 4.0°C and 30.0°C. The level of decantation may be determined as described elsewhere in the description. In particular embodiments, the method as taught herein does not comprise adding more than 0.50 wt%, such as more than 0.20 wt%, more than 0.05 wt%, or more than 0.01% of gums and / or hydrocolloids to the liquid mixture(s) and / or to the liquid sourdough product.

[0072] A further aspect provides a stable liquid sourdough product, preferably wherein said liquid sourdough product is obtained or obtainable by the method as described herein. In particular embodiments, the liquid sourdough product comprises cereal(s) and / or cereal fractions, is fermented by one or more strains of Weissella confusa and has a level of decantation of less than 5% after 24 hours storage at a temperature between 4.0°C and 30.0°C. In a particular embodiment, the liquid sourdough product as taught herein is free (0.0 wt%) from gums and / or hydrocolloids. In embodiment, the liquid sourdough product as taught herein is substantially free from gums and / or hydrocolloids, or in other words, in embodiments, the liquid sourdough product as taught herein comprises less than 0.50 wt%, preferably less than 0.20 wt%, more preferably less than 0.05 wt% or even 0.0 wt% of gums and / or hydrocolloids. Preferably the liquid sourdough product as taught herein is clean label.

[0073] In particular embodiments, the liquid sourdough product as taught herein is an active or inactive stable liquid sourdough product.

[0074] The liquid sourdough product as taught herein may be a living sourdough containing living lactic acid bacteria such as, but not limited to, living Weissella confusa, preferably living Weissella confusa LMG S-33544. In a particular embodiment, when the stable liquid sourdough product is a living sourdough, the liquid sourdough product contains at least 107living cells / g of lactic acid bacteria, preferably living Weissella confusa, more preferably living Weissella confusa LMG S- 33544 .

[0075] The liquid sourdough product as taught herein may be an active sourdough product. By this is meant that the stable active sourdough product contains active and / or viable CO2 producing microorganisms such as, but not limited to, yeast(s). An active sourdough product can be used, for example, as a starter to produce baker doughs. An active sourdough product may be advantageously characterized by its fermentation power. The fermentation power may be measured by any means known in the art, such as by using a Risograph (eNational Manufacturing Co., Lincoln, NE) to measure the production of gas during dough fermentation. For example, in the Risograph method, samples of dough are incubated in glass jars in a temperature-controlled water bath. The gas production is measured as back pressure and converted into volume via the gas law equation PV = nRT. After the measurement of pressure, the gas is released returning the cell to atmospheric pressure. The elimination of back pressure allows the yeast to release the gas during the entire fermentation process.

[0076] The liquid sourdough product as taught herein may be an inactive sourdough product. By this is meant that the stable sourdough product does not contain any active and / or viable microorganisms or does not contain active and / or viable microorganisms in an amount sufficient to allow, for example, its use as a starter culture in a dough.

[0077] In a particular embodiment the liquid sourdough product as taught herein further comprises one or more additional strains of lactic acid bacteria and / or strains of yeasts. For example, the one or more strains of lactic acid bacteria may be chosen from strains of Lactobacillus sp. More in particular, the one or more strains of yeasts may be chosen from strains of Saccharomyces or Kazachstania sp.

[0078] The liquid sourdough products as taught herein are particularly resistant to decantation. The term "decantation stability" or "level of decantation" in the context of the present invention refers to the ability of a liquid sourdough to remain homogeneous during storage for a certain period of time. The most obvious way of noticing decantation is the appearance in a container, where a liquid sourdough product is stored, of a (more opaque) layer at the bottom of the container. This usually results from the accumulation of particles. Decantation (stability) may be advantageously evaluated by measuring the water layer formed on top of the sourdough over the shelf life. The result of the measure, expressed in level of decantation, corresponds to a percentage of liquid formed in comparison with the total volume of the liquid sourdough. For example the level of decantation may be determined by pouring a liquid sourdough product in a graduated cylinder and measuring the height of the water layer at the top after a defined time limit. In some embodiments the liquid sourdough product as taught herein has a level of decantation below 5%, preferably less than 2%, more preferably less than 1% or even 0%, when stored for at least one week, such as at least two weeks, at least three weeks or at least four weeks, preferably at least one month or longer at a temperature between 4.0 and 30.0°C.

[0079] In a particular embodiment the liquid sourdough product as taught herein is characterized by having a dry matter between 5% (w / w) and 50% (w / w), preferably between 10% (w / w) and 40% (w / w), more preferably between 10% (w / w) and 35% (w / w). Said range thus also provides any of 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27 , 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48 and 49% dry matter.

[0080] The stable liquid sourdough product as taught herein may be characterized by its pH. Preferably the pH of the liquid sourdough as taught herein is between 5.0 and 2.5, more preferably between 4.5 and 3.0.

[0081] The liquid sourdough product as taught herein may be characterized by its Total Titratable Acidity (TTA). The Total Titratable Acidity of a sourdough product is a product property commonly known to the person skilled in the art. The TTA refers to the amount (expressed in ml) of 0.1 N NaOH needed to bring the pH of 10 g of product to 8.3. Preferably the TTA of the liquid sourdough product as taught herein is between 5 and 50, more preferably between 10 and 25. According to particular embodiments, the liquid sourdough product as taught herein does not comprise (intentionally added) ingredients to improve / increase its stability, preferably the decantation stability as taught herein. Examples of ingredients that can be used to improve the decantation stability are gums and / or hydrocolloids. Non-limiting examples of gums and hydrocolloids are carrageenan (E407), sodium alginate (E401), locust bean gum (E410), guar gum (E412), cellulose gum (E466), colloidal microcrystalline cellulose (E460), gellan gum (E418), gum arabic (E414), pectin high ester (E440), propylene glycol alginate (E405) and xanthan gum (E415).

[0082] In preferred embodiments the stable liquid sourdough product as taught herein is a clean label stable liquid sourdough. In the context of the present invention a clean label liquid sourdough product is a liquid sourdough product that does not contain any (or substantially no) (intentionally added) ingredient characterized by having a E-number requiring a declaration on the packaging. In particular embodiments, the stable liquid sourdough product as taught herein contains less than 0.50 % (VJ / VJ), preferably less than 0.20 % (VJ / VJ), more preferably less than 0.05 % (VJ / VJ), such as less than 0.01% (w / w) or even 0 % (w / w) of E-numbered ingredient(s), such as gums and / or hydrocolloids.

[0083] According to a particular embodiment, the liquid sourdough product as disclosed herein further comprises additional ingredients such as, but not limited to yeast extract, salt(s), sugar(s), oxidant(s), reducer(s), enzyme(s), protein(s), fat(s), or any combination thereof. Preferred additional ingredients are enzyme(s) and / or sugar(s).

[0084] In a further aspect, the present application relates to the use of a liquid sourdough product as disclosed herein as an ingredient of a food product, preferably bakery or patisserie products.

[0085] In a further aspect, the present application relates a method of preparing a food product, preferably a bakery or patisserie product, comprising admixing the liquid sourdough product as described herein and one or more additional ingredients.

[0086] In a particular embodiments, such as if the food product is a baked product, the method further comprises baking the mixture of the liquid sourdough product and the one or more additional ingredients typically used in the preparation of food products, preferably bakery or patisserie products, such as yeast, salt, margarine, improver, water and / or flour.

[0087] In a further aspect, the present application relates to a food product comprising a liquid sourdough product as disclosed herein. Preferably the food product is a bakery or patisserie product. In embodiments, the food product is prepared from a dough or batter comprising the stable liquid sourdough product as taught herein. In the present context a baked product is a bakery or patisserie product known in the art, such as for instance those selected from the group comprising bread, brioche bread, soft rolls, bagels, donuts, Danish pastry, hamburger rolls, pizza, pita bread, ciabatta, sponge cakes, cream cakes, pound cakes, muffins, cupcakes, steamed cakes, waffles, brownies, cake donuts, yeast raised donuts, baguettes, rolls, crackers, cookies, pie crusts, rusks and / or other baked products. More in particular the baked product is bread, baguettes and / or rolls.

[0088] The person skilled in the art will understand that the embodiments of the methods as described herein also apply to the products and / or uses as described herein, and vice versa, unless stated otherwise.

[0089] The invention will be further illustrated with the following examples, without restricting the scope to the specific embodiments described.

[0090] Examples

[0091] Example 1: Strains and media

[0092] The strains used are listed in table 1:

[0093] Table 1

[0094] * isolated from Qu starter

[0095] LMG = BCCM / LMG Bacteria Collection, Laboratory of Microbiology, Ghent University; Belgium.

[0096] Media: The strains of Table 1 were maintained and propagated on MRS-5 medium (10 g / l tryptone, 5 g / l meat extract, 5 g / l yeast extract, 10 g / l maltose, 5 g / l fructose, 5 g / l glucose, 5 g / l C2H3NaO2.3H2O, 3 g / l ammonium chloride, 2.6 g / l K2HPO4.3H2O, 4 g / l KH2PO4;, 0.1 g / l MgSO4.7H2O, 0.05 g / l MnSO4.4H2O, 0.5 g / l cysteine-HCI; 1 ml Tween-80; 0.4 ml vitamin mixture (cobalamin, folic acid, nicotinic acid amide, pantothenic acid, pyridoxal phosphate and thiamine (each 0.2 g / l H2O)); pH5.8)

[0097] Starter cultures:

[0098] The starter cultures were stored on microbeads in a cryosolution (Microbank, Pro Lab Diagnostics) in a -80°C freezer. One microbead is inoculated on a plate with MRS-5 medium containing 1.5% of agar. The plate is incubated at 30°C for 72h. 5 colonies are transferred from the plate to 50 ml liquid MRS-5 medium and incubated at 30°C for 20h.

[0099] Example 2 : Stable liquid sourdough product

[0100] Liquid sourdough products were prepared as follow: preparing a wheat flour (Pur8, Ceres, Belgium) suspension in water (35% flour + 65% water), adding 150 Amyloglucosidase Units (AU) Aspergillus niger glucoamylase / 100 g of suspension (Gluco-amylase 1100 BG, Novonesis), adding a starter of the strains of table 1 at a final concentration of 107living cells / g sourdough, fermenting the suspension at 22°C and 100 rpm in a rotary shaker for 6 hours, adding 10.0% sucrose after the first 6h of fermentation, and further fermenting for 18h at 22°C and 100 rpm, thereby obtaining the liquid sourdough product.

[0101] Liquid sourdough products characterization:

[0102] • Decantation

[0103] The decantation of the liquid sourdough products was evaluated as follow:

[0104] A 100 ml graduated cylinder is filled with the liquid sourdough and the position of the interface between the slurry (viscous) part and the liquid part (if any) at the top of the product was determined after a fixed period of storage at about 4°C. Results

[0105] Table 2 nd : not determined The results show that a stable (non-decanting) liquid sourdough product is obtained only if a strain of Weissella confusa is used.

[0106] Example 3 : Different concentrations of sucrose

[0107] Liquid sourdough products were prepared as in example 2 using a starter culture of Weissella confusa LMG S-33544 and adding different concentrations of sucrose (0, 2.5, 5.0, 7.5 and 10.0 %) after the first fermentation step. The results of the characteristics of the liquid sourdough products are presented in table 3.

[0108] Table 3. nd : not determined

[0109] The results that at least 5% of sucrose should be added to prevent decantation of the liquid sourdough products.

[0110] Example 4 : Other sugars

[0111] Liquid sourdough products were prepared as in example 2 using a starter culture of Weissella confusa LMG S-33544 and 10.0 % of glucose was added instead of sucrose after the first fermentation step. The results of the characteristics of the liquid sourdough products are presented in table 4.

[0112] Table 4

[0113] Example 6 : Different concentrations of amyloglucosidase

[0114] Liquid sourdough products were prepared as in example 2 using a starter culture of Weissella confusa LMG S-33544 and different concentrations of amyloglucosidase (gluco-amylase 1100 BG, Novonesis) was added.

[0115] The results of the characteristics of the liquid sourdough products are presented in table 5.

[0116] Table s

[0117] Example 8 : Sourdoughs with different flours Liquid sourdough products were prepared as in example 2 using starter cultures of Weissella confusa LMG S-33544 or of Lactiplantibacillus plantarum LMG 9206, using different types of flours: wheat flour and whole meal wheat flour (Ceres, Belgium) and rye flour (Plange GmbH, Germany - used at 30% instead of 35%).

[0118] The results of the characterization of the liquid sourdough products are presented in table 6. Table 6

[0119] The results show that it is possible to obtain stable (non-decanting) liquid sourdough products by using other types of flour like whole meal wheat flour and rye flour using Weissella confusa instead of the commonly used Lactiplantibacillus plantarum.

[0120] Example 8 : Different processes

[0121] Liquid sourdough products were prepared as in example 2 using a starter culture of Weissella confusa LMG S-33544 with the following modifications:

[0122] 1. Same as in example 2

[0123] 2. Sucrose added before fermentation

[0124] 3. Sucrose added before fermentation and with addition of 0.6% xanthan gum at the end of the second fermentation.

[0125] 4. Sucrose added after 4 hours of fermentation

[0126] 5. Sucrose added after 16 hours of fermentation

[0127] 6. Sucrose added after 24 hours of fermentation followed by a second fermentation of 24 hours instead of 18 hours. The results of the characterization of the liquid sourdough products obtained with the different processes are presented in table 7.

[0128] Table ? Example 9: Use of the liquid sourdough product in baking

[0129] Liquid sourdough products obtained with processes 1 to 3 of example 8 (respectively SI, S2 and S3) were used in the preparation of lean breads.

[0130] Doughs compositions are presented in Table 8

[0131] Table 8

[0132] Process:

[0133] The ingredients were mixed for 2 min at low (speed 1) and 6 min at high speed (speed 2) in a Diosna SP24 mixer. The final dough temperature was 27°C. The doughs were moulded manually (600 g dough pieces) and underwent an intermediate proof at 21°C for 10 min at 60% relative humidity in the Bakery lab. 600 g dough pieces were made up using the on the line Quality & Ethics - Jac Unic set at R4 / L9and moulded. The dough pieces obtained a final proof at 35°C for 80 min at 95% relative humidity in a Koma SunRiser. Then the breads were baked at 250°C during 28 min in a Miwe Condo Oven (Michael Wenz- Arnstein - Germany). The breads were cooled down during 90 min.

[0134] No differences in the hardness, the stickiness or the elasticity of the crumb were noticed between the three types of bread.

[0135] The results show that the stabilization of the sourdough does not alter the techno-functional properties of the sourdough.

Claims

Claims:

1. A method for preparing a liquid sourdough product comprising the steps of: a) adding amyloglucosidase to a liquid mixture comprising cereal(s) and / or cereal fractions and water, wherein said liquid mixture has a dough yield between 150 and 500 and wherein said amyloglucosidase is added to said liquid mixture in an amount between 20 and 500 Amyloglucosidase Units (AU) / 100 g of said liquid mixture; b) inoculating the liquid mixture obtained in step a) with one or more strains of Weissella confusa at a concentration of between 105and 109living cells / g of liquid mixture; c) fermenting the liquid mixture obtained in step b) for a period between 4 and 8 hours at a temperature between 15.0 and 40.0°C; d) adding between 5.0 and 20.0 % (w / w) of sugar to the fermented liquid mixture obtained in step c); and e) further fermenting the fermented liquid mixture obtained in step d) at a temperature between 15.0 and 40.0°C for a period between 18 and 48 hours, thereby obtaining a liquid sourdough product.

2. The method according to claim 1, wherein said liquid mixture is fermented in steps c) and / or e) by one or more microorganisms in addition to the one or more strains of Weissella confusa, wherein said microorganisms are chosen from a lactic acid bacteria strain and / or a yeast strain, preferably wherein the lactic acid bacteria strain is a strain of Lactobacillus and / or the yeast strain is a strain of Saccharomyces or Kazachstania.

3. The method according to claim 1 or 2, wherein said sugar comprises sucrose.

4. The method according to any one of claims 1 to 3, further comprising a step of inactivating the one or more strains of Weissella confusa and optionally the one or more microorganisms in addition to the one or more strains of Weissella confusa, wherein said step is performed after step e).

5. The method according to any one of claims 1 to 4, further comprising a step of cooling and / or packing the liquid sourdough product.

6. A liquid sourdough product comprising cereal(s) and / or cereal fractions, wherein said liquid sourdough product is fermented by one or more strains of Weissella confusa; andwherein the level of decantation of said liquid sourdough product is less than 5% after 24 hours storage at a temperature between 4.0°C and 30.0°C.

7. The liquid sourdough product according to claim 6, comprising less than 0.50 % of gums and / or hydrocolloids.

8. The liquid sourdough product according to claim 6 or 7 , wherein said liquid sourdough product has a pH between 5.0 and 2.5, more preferably between 4.5 and 3.0.

9. The liquid sourdough product according to any one of claims 6 to 8, wherein said sourdough product is an active or inactive sourdough product.

10. The liquid sourdough product according to any one of claims 6 to 9, wherein said one or more strains of Weissella confusa comprise Weissella confusa LMG S-33544.

11. The liquid sourdough product according to any one of claims 6 to 10, wherein said liquid sourdough product is obtained or obtainable by the method according to any one of claims 1 to 5.

12. Use of the liquid sourdough product according to any of the claims 6 to 11 as an ingredient of a food product, preferably a bakery or patisserie product.

13. A method of preparing a food product, preferably a bakery or patisserie product, comprising admixing the liquid sourdough product according to any one of claims 6 to 11, and one or more additional ingredients.

14. A food product comprising the liquid sourdough product according to any one of claims 6 to 11.

15. The food product according to claim 14, wherein said food product is a bakery or patisserie product.

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