Method for producing fermented dough and method for producing bakery food products

Abstract

To provide a method for producing a fermented dough and a method for producing bakery food products capable of imparting superior flavor and texture to bread and baked confectionery.SOLUTION: A method for producing a fermented dough comprises a step of fermenting a mixture containing a zygomycete belonging to the Mucor order Mucor phylum and a fermentation substrate. The zygomycete is a filamentous fungus, preferably one or more zygomycetes selected from the genera Mucor, Helicostylis, Rhizopus, Umbelopsis, and Zygorhynchus. The mixture preferably contains bread yeast.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a method for producing a leaven and a method for producing a bakery food product. [Background technology]

[0002] A starter is a dough-like fermented substance made by growing yeasts and multiple microorganisms naturally found on grains, fruits, etc., and is used as an ingredient in bread and confectionery. Examples of starters include sourdough and sake starter, which are used to improve the flavor and taste of bread.

[0003] For example, Patent Document 1 discloses a fermentation starter characterized by containing dextran, yeast, and koji. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2021-019555 Summary of the Invention [Problem to be solved by the invention]

[0005] Bread and baked goods are required to have better flavor and texture, and improvements in flavor and texture are required. The present invention has been made in consideration of the above circumstances, and aims to provide a method for producing a leaven and a method for producing bakery foods that can impart better flavor and texture to bread and baked goods. [Means for solving the problem]

[0006] That is, the present invention includes the following inventions. [1] A method for producing a fermented starter, comprising a step of fermenting a mixture containing a zygomycete belonging to the order Mucorales of the phylum Mucorales and a fermentation substrate. [2] The method for producing a fermentation starter according to [1], wherein the zygomycete is a filamentous fungus and is one or more zygomycetes selected from the genera Mucor, Helicostylum, Rhizopus, Umbelopsis, and Pseudomonas. [3] The method for producing a leaven described in [1] or [2], wherein the mixture contains baker's yeast. [4] The method for producing a fermentant according to any one of [1] to [3], wherein the mixture contains lactic acid bacteria. [5] The method for producing a fermented starter according to any one of [1] to [4], wherein the fermented starter is a co-fermented product of a zygomycete belonging to the order Mucorales of the phylum Mucorales and a lactic acid bacterium. [6] A method for producing a fermentation starter according to any one of [1] to [5], wherein the lactic acid bacterium is Lactococcus lactis. [7] A method for producing bakery food, comprising the steps of obtaining a leaven by the method for producing a leaven described in any one of [1] to [6], preparing bakery dough containing the leaven, and baking the bakery dough to produce bakery food. [Effects of the Invention]

[0007] According to the present invention, it is possible to provide a method for producing a leaven and a method for producing bakery foods that can impart better flavor and texture to bread and baked goods. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 shows the results of measuring the viscosity of the fermented starter produced in Example 4. [Figure 2] FIG. 1 shows the results of observing the structure of the fermented seed produced in Example 4. [Figure 3] FIG. 1 shows the viscosity and viscoelasticity of fermented seeds. [Figure 4] FIG. 1 shows the viscosity and viscoelasticity of fermented seeds. [Figure 5] FIG. 1 is a graph showing the weight loss rate (moisture content) of the fermented seeds. [Figure 6] FIG. 1 shows the ethanol concentration of fermented species. [Figure 7]FIG. 1 shows the viscoelastic properties of fermented seeds. [Figure 8] FIG. 1 shows the viscosity of fermented seeds. [Figure 9] FIG. 1 is a graph showing the weight loss rate (moisture content) of the fermented seeds. [Figure 10] 1 shows the results of tissue observation of a fermented seed using Zygomycete 2 (derived from the genus Rhizopus) produced in Example 8. [Figure 11] 1 shows the results of tissue observation of a fermented seed using Zygomycete 4 (derived from the genus Mucor) produced in Example 8. [Figure 12] FIG. 10 is a diagram showing the results of measuring the breaking strength of crumb. [Figure 13] FIG. 10 is a diagram showing the results of measuring the breaking strength of the crust. [Figure 14] FIG. 1 shows the results of texture analysis of bread dough. [Figure 15] FIG. 1 shows the results of crumb texture analysis. DETAILED DESCRIPTION OF THE INVENTION

[0009] <How to produce fermented starter> The present invention is a method for producing a fermented starter, which comprises a step of fermenting a mixture containing a zygomycete belonging to the order Mucorales (Mucorales) of the phylum Mucormycota (Zygomycota) and a fermentation substrate.

[0010] Zygomycetes chemically or physically decompose the substrates sugars and proteins. The inventors believed that the sugar and protein decomposition products produced by chemical decomposition can impart various flavors, such as richness and depth, to confectioneries and breads, and that the sugar and protein decomposition products produced by physical decomposition can impart new textures to confectioneries and breads, and thus completed the present invention.

[0011] The zygomycete used in the present invention is a zygomycete belonging to the Mucorales order of the phylum Mucormycota (Zygomycota), and is preferably a filamentous fungus, and is preferably one or more zygomycetes selected from the genera Mucor, Helicostylum, Rhizopus, Umbelopsis, and Pseudomonas. Hereafter, zygomycetes belonging to the Mucorales order of the Mucorales phylum (Zygomycota) may be referred to as zygomycetes. Zygomycetes were previously classified as either the Zygomycetes or the Zygomycota phylum, but as a result of phylogenetic analysis of the fungal kingdom as a whole, the classification has been reconsidered, and the phylum Mucor is also called Mucorales, which refers to the Zygomycetes other than the phylum Atropomyocota, which are saprophytic or primarily parasitic on animals. The order Mucorals is also called Mucorales, and is a classification that includes many fungi within the phylum Mucorales.

[0012] Bacteria belonging to the genus Mucor include Mucor plasmaticus (NBRC9260), Mucor albo-ater (NBRC9399), Mucor piriformis (NBRC 9413), and Mucor strictus (NBRC9563).

[0013] Fungi belonging to the genus Helicostylum include Helicostylum pulchrum and Helicostylum elegans.

[0014] Fungi belonging to the genus Rhizopus include Rhizopus oryzae (NBRC4705) and Rhizopus stolonifer var stolonifer (NBRC5411).

[0015] An example of a fungus belonging to the genus Umbelopsis is Umbelopsis ramanniana (NBRC105996). An example of a fungus belonging to the genus Zygorhynchus is Zygorhynchus Moelleri (NBRC105999).

[0016] As the zygomycete, fungi belonging to the genus Tamnidium can also be used. An example of a fungus belonging to the genus Thamnidium is Thamnidium elegans.

[0017] In one embodiment of the present invention, different flavors and textures can be imparted to bread and baked goods depending on the type and amount of zygomycete. For example, by adding a zygomycete or increasing the amount of zygomycete added, bakery foods such as bread and baked goods with an adjusted texture can be produced, such as those with an increased chewiness or a texture that is highly chewable.

[0018] The above-mentioned zygomycetes can grow in low-temperature regions below 20°C. In low-temperature regions below 20°C, other bacteria are less likely to grow, creating an environment in which the zygomycetes and yeasts described below can easily function.

[0019] The fermentation substrate is preferably a cereal flour such as rye flour, wheat flour, or rice flour. These cereal flours may be used alone or in combination. The fermentation substrate may also contain sugars such as refined sugar or raw sugar.

[0020] Preferably, the mixture containing the zygomycete and the fermentation substrate further contains water.

[0021] Preferably, the mixture containing the zygomycete and the fermentation substrate further contains baker's yeast. The baker's yeast is not particularly limited as long as it belongs to the genus Saccharomyces cerevisiae, and commercially available baker's yeast can be suitably used. Fresh yeast, dry yeast, instant dry yeast, etc. can be used, and the form is not particularly limited. Specific examples include SAF (instant dry yeast, SAF Co.), Fermipan (red) (dry yeast, SAF Co.), and fresh yeast manufactured by Kaneka Corporation.

[0022] The amount of baker's yeast added is, for example, 0.01 to 5 parts by weight, preferably 0.1 to 1 part by weight, and more preferably 0.2 to 0.6 parts by weight, relative to 100 parts by weight of flour.

[0023] Preferably, the mixture containing the zygomycete and the fermentation substrate further contains lactic acid bacteria. The organic acids produced by the lactic acid bacteria lower the pH of the mixture, inhibiting the growth of unwanted bacteria and creating an environment that is favorable for the zygotes and yeasts described below to function.

[0024] Combining lactic acid bacteria with zygomycetes can impart different flavors and textures to bread and baked goods. For example, combining lactic acid bacteria with bacteria belonging to the genus Mucor can produce bread with a chewy texture.

[0025] It is preferable to include Lactococcus lactis as the lactic acid bacterium.

[0026] The fermented species obtained by the present invention is preferably a co-fermentation product of a zygomycete belonging to the order Mucorales in the phylum Mucorales and a lactic acid bacterium.

[0027] During the fermentation of bread dough, a complex network structure is formed due to interactions between microorganisms (e.g., zygomycetes, lactic acid bacteria, and yeast), extracellular polymers produced by lactic acid bacteria, gluten formed during fermentation, etc. It is preferable to adjust the density of this network structure by combining lactic acid bacteria and zygomycetes, and to change the physical properties of the leavening agent to suit the desired flavor and texture.

[0028] The fermentation conditions for the step of fermenting the mixture are not particularly limited, and the fermentation temperature is within the range of 20°C to 40°C, and the fermentation time can be appropriately adjusted within the range of 24 hours or less. In the present invention, in order to prevent deterioration of flavor due to over-fermentation, the fermentation time in the step of obtaining a fermented starter is set to within 72 hours, preferably 48 hours or less. The target pH at the end of this step is 3.8 to 4.3.

[0029] One embodiment of the method for producing a fermented starter of the present invention comprises a first fermentation step in which a mixture containing a zygomycete and a fermentation substrate is fermented, and a second fermentation step in which baker's yeast is further added and fermented. One embodiment of the method for producing a fermented starter of the present invention includes a fermentation step of fermenting a mixture containing a zygomycete, a fermentation substrate, and baker's yeast. One embodiment of the method for producing a fermented starter of the present invention comprises a first fermentation step in which a mixture containing a zygomycete, a fermentation substrate, and lactic acid bacteria is fermented, and a second fermentation step in which baker's yeast is further added and fermented. One embodiment of the method for producing a fermented starter of the present invention includes a fermentation step of fermenting a mixture containing a zygomycete, a fermentation substrate, lactic acid bacteria, and baker's yeast. One embodiment of the method for producing a fermented starter of the present invention comprises a first fermentation step in which a mixture containing a zygomycete and a fermentation substrate is fermented, and a second fermentation step in which baker's yeast is further added and fermented. One embodiment of the method for producing a fermentant of the present invention includes a fermentation step of fermenting a mixture containing a zygomycete, a fermentation substrate, lactic acid bacteria, and baker's yeast. In addition, in order to improve the flavor and physical properties of the fermented milk by combining these, it is also possible to add the conjugated bacteria from the second fermentation step rather than adding them in the first fermentation step.

[0030] <Bakery food manufacturing method> One aspect of the present invention is a method for producing bakery foods, comprising the steps of obtaining a leaven using the leaven production method of the present embodiment described above, preparing bakery dough containing the leaven, and baking the bakery dough to produce bakery foods.

[0031] Bakery foods are foods obtained by adding liquids such as water or milk to powdered ingredients such as grain flour (e.g., wheat flour) or starch, and then fermenting the dough as necessary, followed by heating such as baking or frying. Examples of bakery foods include hard breads such as baguettes, batards, Parisien breads, campagne breads, ciabatta breads, and other French breads, soft breads such as white bread, sweet breads, and rolls, bagels, croissants, brioches, donuts, and cookies.

[0032] The method for producing bakery foods is not particularly limited, and any of the straight dough method, sponge dough method, yeast method, and liquid dough method can be used. The method for producing bread usually includes mixing (kneading), dividing, shaping, proofing (final rise), and cooking.

[0033] The cereal flour used in the production of the bakery food of the present invention can be any flour that is commonly used as a raw material for bread foods, such as bread wheat flour, whole wheat flour, rye flour, oat flour, corn flour, rice flour, buckwheat flour, starches, dietary fiber, and mixtures thereof.

[0034] In the present invention, in addition to the leaven and cereal flour of the present invention, various additives acceptable for manufacturing bakery foods, such as salts, sugars, dried eggs, powdered oils and fats, powdered milk, flavorings, baker's yeast, baking powder, emulsifiers, humectants, oxidizing agents, reducing agents, powdered vegetable protein, and gluten, may be included in all or a combination of several types.

[0035] When the leavening agent of the present invention is used primarily to improve taste and flavor, and baker's yeast is added separately to cause the leavening of bakery food dough, the amount of leavening agent added is 3 to 20 parts by weight, more preferably 5 to 15 parts by weight, and even more preferably 7 to 10 parts by weight, per 100 parts by weight of flour.

[0036] When using baker's yeast, any of general-purpose yeast, dry yeast, instant yeast, etc. is usable. There are no particular restrictions on the amount of yeast to be added, and the required amount may be added depending on the type of bakery food and the manufacturing method, etc., but generally, when dry yeast is used for 100 g of grain flour used to make bread, good results are obtained by adding 2 to 8 g of baker's yeast.

[0037] Depending on the type of bakery food product desired, one or more of the following additives may be used as needed before kneading or during dough preparation: salt; sugar and other sugars; fats and oils such as shortening, butter, and margarine; malt powder and malt syrup; yeast food; vital gluten; dairy products such as skim milk powder, whole milk powder, cheese powder, yogurt powder, and whey powder; eggs and egg products; bean powder; vitamins; minerals; ammonium chloride, calcium carbonate, calcium sulfate, calcium dihydrogen phosphate, and ammonium sulfate.

[0038] [Frozen, etc.] Bakery foods produced using the leaven obtained by the present invention can be frozen at the stage of dough before baking, or at the stage of bread dough before fermentation, or even as bread after baking.

[0039] Freezing can be carried out appropriately using existing equipment, but for example, freezing can be carried out in a freezer for about 30 to 40 minutes by blowing air at 5 m / s in an environment of -35°C to -30°C. After freezing, it is recommended to store the product in a freezer warehouse at -18°C or below.

[0040] In the case of dough balls before baking, after the dough is made, it can be rolled into balls or shaped and allowed to complete the final fermentation and then frozen in a freezer. In the case of dough balls, the dough that has been thawed, fermented, shaped and frozen can be baked as is to provide bread.

[0041] After baking, frozen bakery foods can be packaged individually or in multiples, either before or after freezing. To prevent drying during the frozen storage period (including transportation and sales), bags with water vapor barrier properties (the ability to prevent water vapor transmission) can be used. Bread products packaged in bags can be further packed in cardboard boxes for transportation and storage.

[0042] Such baked and frozen bakery foods can be thawed naturally or, if necessary, heated in an oven, microwave oven or the like and then served. Baked and frozen bakery foods usually develop a sour taste and a fermented odor when frozen for 1 to 2 weeks, resulting in a deterioration in flavor. However, according to studies by the present inventors, the baked and frozen bakery foods obtained by the present invention maintained a good flavor even after being frozen for 2 to 3 weeks. Therefore, it can be said that the leaven of the present invention is particularly suitable for producing baked and frozen bakery foods. [Example]

[0043] (1) Identification of isolated strains (1-1) Preparation of medium for strain identification To prepare a medium for recovering fungal cells, 1 g of yeast extract (Difco), 1 g of polypeptone (Nihon Pharmaceutical Co., Ltd.), 2 g of D-glucose, and 80 mL of distilled water were added to a 200 mL Erlenmeyer flask, stirred to completely dissolve, and then the volume was adjusted to 100 mL. Subsequently, 5 mL of the 100 mL medium was dispensed into test tubes, autoclaved, and used as PGY (Peptone, Glucose, Yeast Extract) liquid medium for recovering the isolated strains.

[0044] To prepare the medium for the E. coli transformant strain used in the identification experiment, 0.5 g of yeast extract (Difco), 1 g of polypeptone (Nihon Pharmaceutical Co., Ltd.), 1 g of sodium chloride, and 80 mL of distilled water were mixed and dissolved by stirring. The pH was then adjusted to 6.8-7.0 with 1N sodium hydroxide solution. The volume was then adjusted to 100 mL and 2 mL of the mixture was dispensed into test tubes. To prepare agar plates, 1.5 g of agar was added to the final volume and dissolved in a hot water bath. After autoclaving, the agar plates were irradiated with UV light for 15 minutes in a clean bench. Ampicillin sodium (50 μg / mL), isopropyl-β-D(-)-thiogalactopyranoside (1 mM), and 5-bromo-4-chloro-3-indolyl-β-D-galactopyranoside (0.04%) were added to the final concentrations shown in parentheses. The plates were then dispensed into sterilized plastic Petri dishes to prepare LB agar plates for obtaining transformants. Before culturing for recovering the plasmid, 2 mL of LB liquid medium was added with sodium ampicillin to a final concentration of 50 μg / mL before use in the culture.

[0045] (1-2) Identification of strains The isolated strains were identified based on the nucleotide sequence of the 28S rRNA gene and the internal transcribed sequence (ITS: described below) using the method described below.

[0046] (1-2-a) Preparation of DNA from bacterial cells To recover the bacterial cells, the isolated strains were cultured in PGY liquid medium for bacterial cell recovery with shaking at 15°C for 2 days and then filtered by vacuum filtration using a Buchner funnel fitted with Miracloth. DNA was then extracted from the bacterial cells according to conventional methods (reference: Hamamoto, Makiko, "Experimental Methods for Classification and Identification of Microorganisms - Focusing on Molecular Genetics and Biological Techniques," 2. DNA Preparation, 2.2. Yeast and Filamentous Fungi, 2.2.3. Small-Scale Methods, pp. 26-27, Springer-Verlag Tokyo, 2001). The concentration of the extracted DNA was confirmed by 1% agarose gel electrophoresis. HindIII-digested λ-DNA was used as a size marker.

[0047] (1-2-b) Amplification of the 28S rRNA gene by PCR Next, a portion of the 28S rRNA gene was amplified by PCR using the DNA prepared in (1-2-a) above as a template according to conventional methods (reference: Sandhu, GS, Kline, BC, Stockman, L. and Roberts, GD, "Molecular probes for diagnosis of fungal infections," Journal of Clinical Microbiology, 33, 2913-2919, 1995). The primers used were P1 primer (SEQ ID NO: 1: 5'-ATCAATAAGCGGAGGAAAAG-3'), which has a sequence specific to the fungal 28S rRNA gene, and P4 primer (SEQ ID NO: 2: 5'-ACTCCTTGGTCCGTGTTTCA-3'). Amplification was confirmed by 2% (w / v) agarose gel electrophoresis. A 100 bp DNA ladder (Bioneer) was used as a size marker.

[0048] (1-2-c) Purification of PCR amplification products The PCR amplification product was purified using the FavorPrep GEL / PCR Purification Mini Kit (FAVORGEN). Subsequently, the following ethanol precipitation procedure was performed. The PCR amplification product obtained in (1-2-b) above was mixed with 1 / 10 volume of 3M acetate buffer (pH 5.2) and 2.5 volumes of 99.5% EtOH. The mixture was left to stand at 25°C for 15 minutes, then centrifuged (15,400 × g, 15 minutes, 25°C). The supernatant was then removed, and 100 μL of 70% ethanol was added. The mixture was then centrifuged (15,400 × g, 10 minutes, 25°C). The supernatant was then removed, and the mixture was dried under reduced pressure for 10 minutes (hereinafter, this procedure is referred to as "ethanol precipitation"). The resulting precipitate was then dissolved in 4 μL of TE buffer (10 mM Tris-HCl (pH 8.0), 1 mM EDTA). Of this, 1 μL was subjected to 2% (w / v) agarose gel electrophoresis to confirm the recovery of purified PCR amplification products.

[0049] (1-2-d) Ligation of purified PCR amplification products with vector The purified PCR amplification product and pGEM T-Easy Vector Systems I (Promega) were incubated overnight at 12°C to carry out a ligation reaction.

[0050] (1-2-e) Transformation of E. coli and recovery of plasmid ECOS® Competent E. coli DH5α (Nippon Gene Co., Ltd.) was transformed with the ligation reaction mixture prepared in (2-2-d) above according to the product manual. The resulting transformant was then cultured on an LB agar plate at 37°C for 20 hours. A grown colony was then inoculated into 2 mL of LB liquid medium using a sterilized toothpick and cultured with shaking at 37°C for 16 hours. Plasmid DNA was then recovered by alkaline lysis according to a conventional method (reference: Sambrook, J. and Russell, DW, Molecular cloning: a laboratory manual, 3rd ed., "Preparation of plasmid DNA by Alkaline Lysis with SDS: Minipreparation," pp. 1.32-1.34, Cold Spring Harbor Laboratory Press, Cold Spring Harbor, NY, 2001). The recovered plasmid DNA was then dissolved in 40 μL of TE buffer containing 0.2 μL of RNase A solution (10 mg / mL, Sigma-Aldrich). After incubation at 37°C for 5 minutes, 1 μL of the solution was subjected to 1% (w / v) agarose gel electrophoresis to confirm the recovery of plasmid DNA of the desired size. λ-DNA digested with HindIII was used as a size marker.

[0051] (1-2-f) DNA sequencing Next, the plasmid DNA recovered in (1-2-e) above was purified using a FavorPrep GEL / PCR Purification Mini Kit (FAVORGEN). A 1 μL sample of the purified plasmid DNA solution was subjected to 1% (w / v) agarose gel electrophoresis to confirm the recovery of the plasmid DNA. Next, 4 μL of the remaining purified plasmid DNA was used for sequencing. Cycle sequencing was performed using a BigDye® Terminator v3.1 Cycle Sequencing Kit (Applied Biosystems). First, the plasmid DNA was amplified by PCR. The PCR reaction conditions were heating at 96°C for 1 minute, followed by 35 cycles of 96°C for 10 seconds, 50°C for 5 seconds, and 60°C for 4 minutes. The PCR-amplified product was then precipitated with ethanol and dissolved in 15 μL of Hidi formamide (Applied Biosystems). The resulting sample was subjected to a 3130 Genetic Analyzer (Applied Biosystems) to obtain the DNA sequence. The resulting data were analyzed using Chromas LITE version 2.01 (Technelysium Pty Ltd) and GENETYX®-WIN version 3.1.0 (Software Development). Sequences identical to the determined nucleotide sequence were searched against the European Molecular Biology Laboratory (http: / / www.ebi.ac.uk / embl / ) database using the fasta program. Isolates were identified based on the high degree of identity.

[0052] Morphological and 28S rRNA gene sequence analysis revealed high identity among strains from several genera and species in the family Mucoraceae. To identify the genus and species of the isolated strain, designated JW-1, from among the highly identical candidate genera and species, we used the internal transcribed sequence (ITS) region. Candidate strains were selected based on the genus and species listed in a reference (Walther et al., "DNA barcoding in Mucorales: an inventory of biodiversity," Persononia, 30, 2013: 11-47). Specifically, direct sequencing was performed, consisting of DNA preparation from the fungus, PCR, purification of the PCR amplified product, and DNA sequencing. Primers used in PCR were specific for amplifying the base sequence of the ITS region of the strain that showed high identity (JW-ITS-F (SEQ ID NO: 3): 5'-CAACGGATCTCTTGGTTCTC-3', JW-ITS-R (SEQ ID NO: 4): 5'-CCCGCCTGATTTCAGATC-3'). The results are shown in Table 1.

[0053] [Table 1]

[0054] From Table 1, it was found that the identity of strain JW-1 to both species of the genus Helicostylum was 99.5% or more, and the identity to the genera Thamnidium, Mucor, and Pirella was 94.5% or less. Therefore, strain JW-1 was identified as a species of the genus Helicostylum.

[0055] (Sterilization of powder) Many conventional leavens, particularly sourdough, are prepared by mixing wheat flour with water and allowing so-called wild yeasts, such as yeasts attached to rye flour or wheat flour or present in the air, as well as lactic acid bacteria and acetic acid bacteria, to grow through a preliminary fermentation. In this example, in order to verify the effects of microorganisms in more detail, the grain flours used, such as rye flour and wheat flour, were sterilized using ethylene oxide gas before use.

[0056] Specifically, the required amount of grain flour was weighed out, placed in an Elk sterilization bag, sealed, and placed in an EO sterilizer FRH16 (Iki Corporation), which was then degassed and sterilized for 5 hours by injecting ethylene oxide gas. After sterilization, the ethylene gas was discharged, and air cleaning (aeration) was carried out for 14 hours.

[0057] After sterilization, the grain flour was diluted 50 times with sterilized water to obtain 0.1 mL of grain flour solution. When this solution was smeared on PGY medium or MRS agar medium, the colonies observed before sterilization were not formed, confirming that the grain flour had been sterilized by the gas sterilizer.

[0058] The compositions of the PGY medium, MRS agar medium and broth medium used in this example are as follows: PGY medium: 1% bactopeptone, 2% glucose, 0.5% yeast extract, 1.5% agar MRS agar medium: MRS agar medium containing 0.04 g / L bromcresol purple and 1.5% agar (BioKer diagnostics) Broth medium: 1% Ehrlich's bonito extract, 1% hypopeptone, 0.5% sodium chloride, 1.5% agar

[0059] Hereinafter, to distinguish from yeast (baker's yeast), the term "yeast" refers to yeast (Kaneka Yeast GA, manufactured by Kaneka Corporation) that was cultured in PYG medium and isolated as a single colony. Specifically, the yeast was isolated by the following method and used in the tests. Yeast isolation method: First, 0.1 g of each flour or yeast was collected and serially diluted with autoclaved physiological saline to prepare suspensions. 0.1 ml of each suspension was plated onto PGY medium and cultured at 30°C for 48 hours to obtain single colonies.

[0060] Example 1 [Fermented starter production] A fermented starter was created using the following method. In the case of a normal fermented starter, the starter is usually subcultured at 25°C every day, but in this study, the temperature was set at a low temperature (20°C) at which the zygote can grow, and the first stage of cultivation was extended to 2 days (48 hours), and the effect was verified.

[0061] (1st row) First, 10 g of rye flour and 15 g of bread flour were placed in a 200 ml beaker as fermentation substrates. Next, yeast (Kaneka Yeast GA, manufactured by Kaneka Corporation) and a predetermined amount of zygote were taken and dispersed in water, and then added to the fermentation substrate to obtain a mixture. The zygomycetes used were Helicostyrum sp. JW-1 and Thamnidium elegans NBRC5429. The mixture was mixed with a specified amount of water and then left to stand at 20°C for 2 days.

[0062] The composition of the mixture used in the first stage is listed in Table 2.

[0063] [Table 2]

[0064] (Second row) The wheat flour and water shown in Table 3 were added to the original leaven obtained in the first stage, mixed, and allowed to stand at 20°C for 1 day.

[0065] [Table 3]

[0066] (Third row) After the second stage of fermentation, the mixture was further cultured at 15°C for 2 days to obtain a fermentation seed. Fermented starter A was inoculated with Helicostyrum sp. JW-1, fermented starter B was inoculated with Thamnidium elegans NBRC5429, and a control was prepared without using the zygomycete, fermented starter C. After preparing the fermented starter, the taste and physical properties were evaluated.

[0067] (Bread making test) Next, bread was made using each leaven using the formulation shown in Table 4, the dough was kneaded by the straight kneading method, and baked in the usual way. In Table 4, the unit of values ​​is [g].

[0068] [Table 4]

[0069] Table 5 shows the pH of fermented varieties A, B, and C and the results of sensory tests of these fermented varieties.

[0070] [Table 5]

[0071] As shown in Table 5, in the case of fermented starter C, which was the control in which no conjugated fungus was added, a fermented starter with a consistent fermented odor, a strong sour taste, and smooth physical properties was obtained, similar to conventional fermented starters. In contrast, fermented strain A, to which the zygomycete Helicostyrum sp. JW-1 was added, had a strong alcoholic odor and a pungent aroma, was bitter, and was highly viscous. Fermentation B, which contained the zygomycete Thamnidium elegans NBRC5429, had a weak alcoholic odor, a mild aroma, and a mild, slightly sweet taste. The physical properties were also consistent. As described above, certain changes in aroma, taste, and physical properties were observed in fermented starters A and B to which zygotes were added, demonstrating that the characteristics of fermented starters can be changed by adding zygotes.

[0072] Furthermore, bread was made using this leaven, and the results are shown in Table 6. Although this explanation may be redundant, in Table 6, "No fermentation starter" indicates that no fermentation starter was added, "fermentation starter C" indicates that a fermentation starter prepared without the addition of a conjugating fungus was added, and "fermentation starter A" and "fermentation starter B" indicate that a conjugating fungus was added. The leavening agents A and B produced dough that came together more quickly during mixing and had greater expandability than the leavening agent without leavening agent or leavening agent C. Furthermore, after dividing the leavening agent into portions, there was no stickiness, which is often seen with the addition of enzymes, and the dough had good workability. Furthermore, in the baked bread, leavenings A and B produced softer and chewier bread than leavenings C. The sweet aroma characteristic of bread made with leavens A and B was weaker than that of leaven C, but compared to the unleavened starter, it was revealed that they had an ester-based aroma, an aroma reminiscent of bread. It was also revealed that the impression of the aroma differed depending on the type of fungus, demonstrating that the aroma can be changed by changing the type of zygomycete.

[0073] [Table 6]

[0074] From the results of Example 1, it was found that by further adding a conjugated fungus to a conventional system in which flour (wheat flour, rye flour, etc.) is fermented with yeast or wild yeast that is mixed in by leaving it to stand, a leaven with different flavor and physical properties than conventional ones can be obtained. It has long been known that in these conventional leavens, microorganisms (wild yeast, lactic acid bacteria, etc.) adhering to flour, baker's yeast, etc. also contribute greatly to the characteristics of the leaven. Therefore, it was thought that analysis of the bacterial flora was necessary to verify the effect of the conjugated fungus in this study.

[0075] <Example 2> Therefore, we analyzed the action of the microorganisms contained in each raw material of this fermented starter and examined the bacterial flora in each raw material in order to analyze the mechanism of action that gives rise to the flavor of the fermented starter.

[0076] (method) Measurement of bacterial count in raw materials: First, 0.1 g of each flour or yeast was taken and serially diluted with autoclaved physiological saline to prepare suspensions. 0.1 ml of each suspension was applied to a PGY medium and cultured at 30°C for 48 hours, and the number of colonies was counted and observed to determine the number of yeast and other contaminating bacteria. Furthermore, 0.1 ml of each suspension was inoculated onto MRS agar medium containing 0.04 g / L bromcresol purple and 1.5% agar by the pour plate method and cultured at 30° C. for 48 hours, after which the number of colonies was counted and the appearance was observed.

[0077] (result) First, we analyzed the microbial flora in each fermentation material and found that the yeast cells were cultured in PYG medium at 2.8 × 10 9 Furthermore, lactic acid bacteria are 6.8 x 10 4 It was revealed that there are 1000 pieces / g. In addition, neither yeast nor lactic acid bacteria were detected in the strong flour or semi-strong flour, and rye flour contained 3 x 10 bacteria that grow on PYG medium and form red, yellow, and white colonies that form halos. 9 It was revealed that they were present at a rate of about 1 / g.

[0078] Example 3 Next, the microorganisms contained in the yeast were cultured in pure form. [Pure yeast culture] The yeast suspension was diluted onto PYG medium using a platinum loop and then cultured to obtain single colonies. Thereafter, the yeast was used in the experiments as a single isolated yeast.

[0079] [Pure culture of lactic acid bacteria] By culturing the yeast suspension in MRS medium containing bremicresol, a single colony was obtained, and by inoculating the resulting colony into liquid MRS medium, a single lactic acid bacterium was isolated.

[0080] Lactic acid bacteria in yeast were identified by analysis of 16S ribosomal DNA. Specifically, the cell walls of the bacterial cells were disrupted, DNA was extracted, and approximately 1.5 kb of 16S rDNA was amplified by PCR. The amplified DNA fragment was ligated into the pGEM-T easy vector (Promega) and cloned by transforming E. coli DH5α. Plasmids were recovered from the transformed strains using the alkaline SDS method, and the amplified 16S rDNA was sequenced to identify the strains by searching for sequence homology.

[0081] (result) First, the following four strains were isolated based on colony morphology. Strain 1: Circular colonies on the surface of the medium Second strain: Lens-shaped colonies on the surface of the medium Strain 3: Circular colonies in the medium Strain 4: Colonies that formed a halo at the bottom

[0082] Next, when these microorganisms were observed under an optical microscope (1000x magnification), it was revealed that the first strain was largely streptococcal in form, the second strain was a diplococci with a chain of about 2-3 cells, and the third and fourth strains also had a similar diplococci form.

[0083] Furthermore, the results of 16S rDNA sequence analysis of these microorganisms identified strains 1 to 4 as Lactococcus lactis subsp. lactis. From the above, it became clear that yeast contains two types of lactic acid bacteria: strain 1 and strains 2 to 4. However, since strains 2 to 4 are the most numerous and predominant, we decided to subject strain 2 to the following tests to verify its effectiveness.

[0084] Example 4 The results of Examples 2 and 3 revealed that yeast contains lactic acid bacteria in addition to yeast. Therefore, to verify how zygomycetes, yeast, and lactic acid bacteria affect the quality of the leaven, the following leaven 1 to 3 were prepared. The yeast used here was isolated from a single colony and purely cultured.

[0085] Therefore, the following fermentation starter was prepared. Fermentation starter 1: yeast and lactic acid bacteria added (control) Fermentation starter 2: yeast, lactic acid bacteria, and zygote added Fermentation starter 3: Yeast and zygote added

[0086] Fermentants 1 to 3 were obtained in the same manner as in Example 1, except that the composition of the mixture was changed to the composition shown in Table 7.

[0087] [Table 7]

[0088] In Table 7, the yeast and lactic acid bacteria were prepared by the following methods. Preparation of lactic acid bacteria culture medium: Lactic acid bacteria were cultured in liquid MRS medium and used. Preparation of yeast culture solution: A yeast isolated as a single colony from yeast (Kaneka Yeast GA, manufactured by Kaneka Corporation) by the above method was used. The yeast was cultured in PYG medium and used.

[0089] The prepared fermented starter was subjected to viscoelasticity measurement, microscopic observation, and sensory evaluation. The viscosity of the fermented starter was measured using a Brookfield viscometer.

[0090] (Evaluation of the physical properties of fermented seeds) The viscosity measurement results for each fermentation broth are shown in FIG. As a result, it was revealed that the viscosity differed depending on the presence or absence of each microorganism. In particular, Fermentation type 3 containing yeast and zygomycetes (JW-1) and Fermentation type 2 containing yeast, lactic acid bacteria and zygomycetes had higher viscosities than Fermentation type 1.

[0091] Although fermented dough 4, which contained only the zygote (JW-1), was highly viscous, no bubbles or other gaseous components were observed, as was the case with the other doughs. It was presumed that the viscosity increased because only the dough adhered together without any gaseous components, and it was determined that the state of the dough was quite different.

[0092] When comparing samples of Fermented Starters 1 to 3 inoculated with yeast, Fermented Starter 2, which contained all of yeast, lactic acid bacteria, and conjugated bacteria (JW-1), had the highest viscosity, indicating that reducing the amount of microorganisms reduces viscosity. However, Fermented Starters 2 and 3, which were inoculated with conjugated bacteria (JW-1), had particularly high viscosity regardless of whether or not they contained lactic acid bacteria, and Fermented Starter 1, which was not inoculated with conjugated bacteria, had the lowest viscosity. This revealed that the inoculation of conjugated bacteria had a greater effect on the physical properties of the fermented starter than the influence of lactic acid bacteria.

[0093] Therefore, in order to clarify which part of the micro-level structure of the fermented seed specifically contributes to the effect on the physical properties of this fermented seed, we conducted structural observations using an electron microscope. The results of observing fermentation species 1 and 2 at 270x magnification are shown in FIG. In FIG. 2, (A) is the tissue of fermentation species 1, and (B) is the tissue of fermentation species 2.

[0094] Specifically, the structure observation was carried out in the following manner. (Pretreatment) Fermentation species 1 and 2 were subjected to the following pretreatment. After fixation and washing in 2.5% glutaraldehyde (in 0.01M sodium phosphate buffer) at 4°C for one day, the specimens were further fixed in 4% osmium oxide solution at 4°C for 6 hours. After washing with distilled water, the specimens were dehydrated and substituted with absolute ethanol and t-butyl alcohol. The t-butyl alcohol-substituted specimens were frozen, lyophilized, and then metal-coated with osmium oxide. (observation) The above pretreated samples were observed under a JSM-6700F electron microscope.

[0095] As shown in Figure 2(A), a coarse structure with gaps was observed in Fermentation Type 1, which was a co-culture of yeast and lactic acid bacteria. In contrast, as shown in Figure 2(B), a dense structure with fewer gaps was observed in Fermentation Type 2, which was a mixture of yeast, lactic acid bacteria, and zygotic bacteria. The results shown in Figure 2 suggest that zygomycetes and lactic acid bacteria in particular contribute significantly to the physical properties of the fermentation broth.

[0096] As described above, the fermented starter of the present invention using a zygomycete had higher viscosity than the conventional fermented starter. Furthermore, while many gaps were observed in the conventional method, the fermented starter of the present invention had fewer gaps and formed a dense network structure.

[0097] <Example 5> The viscoelasticity of the fermentation starter at room temperature was measured using a stress-controlled rheometer (TA Instruments Japan, ARES-G2). The sample was sandwiched between the geometry (upper plate) and the Peltier (lower plate), and the stress when rotated was measured as viscosity, and the stress when vibrated was measured as viscoelasticity.

[0098] The samples used were a fermented strain using only yeast and a fermented strain using yeast and a zygotic fungus (JW-1). The results are shown in Figure 3. In FIG. 3, G' indicates the strength of elasticity (storage modulus), and G'' indicates the strength of viscosity (loss modulus). G' and G'' have the same meaning hereinafter. It was confirmed that inoculating yeast with JW-1 significantly increased the viscosity and elasticity of the fermented starter compared to yeast alone. It was confirmed that inoculation with JW-1 contributed to improving viscosity and elasticity.

[0099] Next, we created a fermentation starter using yeast containing lactic acid bacteria, and a fermentation starter using yeast alone, which was separated from the yeast, and examined the effect of the lactic acid bacteria in the yeast. As a result, as shown in Figure 4, the viscoelasticity was low and there was little change in the fermentation starter using the yeast carrier. In contrast, when yeast containing lactic acid bacteria was used, there was a large change in viscoelasticity. These results indicate that the lactic acid bacteria in the fermentation starter are involved in viscoelasticity.

[0100] Example 6 Next, to examine the metabolic behavior in the fermentation mixture, the water content and ethanol content in the fermentation mixture were measured. [Weight loss rate (moisture content) measurement] Using a halogen moisture meter, the fermented starter was irradiated with infrared light to dry the sample, and the weight was measured over time. The moisture content was calculated from the weight loss (dry raw material method). Specifically, the entire amount of fermented starter (approximately 43 g) was heated at 105°C for 10 minutes, and the weight loss rate was measured and used as the moisture content. The measurement results of the weight loss rate (moisture content) are shown in Figure 5.

[0101] The weight loss rate increased significantly with the inoculation of JW-1. This suggested that components other than water may have evaporated, so the ethanol content was then measured.

[0102] [Quantitative determination of ethanol content (ethanol concentration)] The ethanol content (ethanol concentration) was determined by an enzymatic method. Specifically, the fermented mixture was diluted with distilled water, shaken for 1 hour, and then centrifuged to collect the supernatant. Trichloroacetic acid was added to the supernatant to remove proteins, and contaminating bacteria were removed using a filter, after which the supernatant was diluted with 10 mM Tris / HCl buffer. Furthermore, measurements were carried out using an F-kit (manufactured by JK International), that is, by quantifying the oxidation reaction of ethanol alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (AI-DH). The ethanol content (ethanol concentration) is shown in FIG.

[0103] Inoculation with yeast increased the ethanol concentration, but when yeast was further inoculated with JW-1, the ethanol content increased further. Furthermore, it was shown that the ethanol content increased further when lactic acid bacteria were inoculated in addition to these. Generally, since ethanol is a metabolic product, its content increases as metabolism progresses. However, it was found that the content increased when zygomycetes were added, and further increased when lactic acid bacteria were also ingested, suggesting that the overall metabolism was promoted by ingesting these microorganisms in combination.

[0104] Example 7 Furthermore, evaluation of bread was carried out using a leaven prepared by inoculating yeast, lactic acid bacteria, and a zygomycete (JW-1) in the same manner as in Example 1. The obtained bread was evaluated by observing the cross section, and by sensory evaluation, particularly with regard to ease of cutting, texture, feel, air bubbles, elasticity, aroma, and taste. The bread was made using a home bakery with the recipes shown in Table 8. Specifically, all ingredients except yeast were placed in a bread machine (Panasonic Home Bakery SD-BH104, Panasonic Corporation), kneaded for 20 minutes, and then left to rest at 20°C for 3 hours. Yeast was then added, and the dough was kneaded for another 20 minutes before being baked using the bread machine's baking function. After cooling to room temperature, the dough was sealed in a bag and temporarily frozen at -20°C. It was then left to thaw at 4°C for one day and subjected to a sensory test.

[0105] [Table 8]

[0106] [Table 9]

[0107] Bread was made using the leaven prepared as described above and subjected to a sensory evaluation. The results are shown in Table 9. As shown in Table 9, although there was some variation in the state and height of the air bubbles, the bread with the leaven added was shown to have a stronger elasticity and chewiness. Furthermore, while the leaven had a bitter taste, the baked bread did not have any bitterness, and instead had a strong sweetness and aroma characteristic of bread.

[0108] Example 8 [Preparation of fermentation starter] Example 4 suggested that the combination of the zygomycete JW-1 and lactic acid bacteria contributed to the modification of the physical properties of the fermented starter. Therefore, fermented starters were also prepared using other zygomycetes and their suitability was tested. The fermented starters were prepared in the following manner, based on the method of Example 1.

[0109] (1st row) First, 10 g of rye flour and 15 g of bread flour were placed in a 200 ml beaker as fermentation substrates. Next, a predetermined amount of yeast, zygote, and lactic acid bacteria were taken and dispersed in water, and then added to the fermentation substrate to obtain a mixture.

[0110] The yeast and lactic acid bacteria used were those isolated from Kaneka Yeast GA (manufactured by Kaneka Corporation).

[0111] The following conjugating fungi were used: Culture at 25℃ Rhizopus oryzae (NBRC4705) Rhizopus stolonifer var stolonifer (NBRC5411)

[0112] Culture at 20℃ Mucor plasmaticus (NBRC9260) Mucor albo-ater (NBRC9399) Mucor piriformis (NBRC 9413) Mucor strictus (NBRC9563) Umbelopsis ramanniana (NBRC105996) Zygorhynchus moelleri (NBRC105999) Helicostylum sp. (JW-1) was used. The mixture was left to stand at the specified temperature for 2 days.

[0113] The composition of the mixture used in the first stage is listed in Table 10.

[0114] [Table 10]

[0115] (Second row) The wheat flour and water shown in Table 11 were added to the original leaven obtained in the first stage, mixed, and allowed to stand at 20°C for 1 day.

[0116] [Table 11]

[0117] (Third row) After the second stage of fermentation, the mixture was further cultured at 15°C for 2 days to obtain a fermentation seed.

[0118] [Weight loss rate (measurement method)] Using a halogen moisture meter, each fermentation starter was irradiated with infrared light to dry the sample, and the weight was measured over time. The weight loss rate was calculated from the weight loss (loss on drying method). Specifically, the entire amount of fermented material (approximately 43 g) was heated at 105° C. for 10 minutes, and the weight loss rate was measured. The results are shown in FIG. The weight of each fungus increased or decreased, but no zygomycetes showed particularly significant increases or decreases.

[0119] Lactic acid bacteria isolated from yeast were combined with nine types of conjugated bacteria, including JW-1, to prepare a fermentation starter. The resulting fermentation starter was subjected to viscoelasticity measurement and sensory evaluation. The results are shown in Table 12.

[0120] [Table 12]

[0121] In Table 12, the numerical results are rated on a scale of 1 to 10 (increasing from 1 to 10 indicates increasing bitterness or sourness). It was revealed that there was no significant difference in bitterness among the Zygomycetes 1 to 9, and that Zygomycetes 3, 8, and 9 had the strongest aroma. In addition, the sourness of some of the Zygomycetes was better than that of JW-1, the Zygomycete 1 already tested in Example 1, compared to the control. In addition, in terms of viscosity, some of the Zygomycetes became sticky, some of the dough became difficult to hold together, and some of the dough became watery.

[0122] Viscoelasticity Next, the viscosity and viscoelasticity of these fermented materials were evaluated. The viscoelasticity of the fermented starter at room temperature was measured using a stress-controlled rheometer (TA Instruments Japan, ARES-G2). The results are shown in Figures 7 and 8. The sample was sandwiched between the geometry (upper plate) and the Peltier (lower plate), and the stress when rotated was measured as viscosity, and the stress when vibrated was measured as viscoelasticity.

[0123] The measurement results of the viscoelasticity of each prepared fermentation species are shown in FIG. 7, and the measurement results of the viscosity are shown in FIG.

[0124] As shown in Figures 7 and 8, there were differences in both viscoelasticity and viscosity among the strains. Specifically, the fermented mixture containing zygomycetes from the genus Mucor (zygomycetes 4 to 7) had particularly high viscoelasticity and viscosity. In addition, the fermentation species derived from the genus Zygorhynchus (Zygomycete 9), the fermentation species derived from the genus Umbelopsis (Zygomycete 8), and JW-1 (Zygomycete 1), which is a member of the genus Helicostylum, exhibited higher viscoelasticity and viscosity than the fermentation species (control) that did not contain these Zygomycetes. In addition, it was revealed that the two fermentation strains containing Rhizopus zygomycetes (zygomycetes 2-3) had lower viscoelasticity and viscosity than the fermentation strain without zygomycetes.

[0125] [Structural observation using a scanning electron microscope (SEM)] The fermented starter produced in Example 8 was subjected to structural observation using an electron microscope (SEM) in the same manner as in Example 4. SEM microstructure observations were performed on the fermented assortment containing a zygomycete from the Mucor genus (zygomycete 4), which had particularly high viscoelasticity and viscosity, and the fermented assortment containing a zygomycete from the Rhizopus genus (zygomycete 2), which had low viscoelasticity and viscosity, from Example 8. The results are shown in Figure 10 (Rhizopus) and Figure 11 (Mucor). As a result, we observed that the fermented soybean containing Rhizopus zygomycetes had few clumps of tissue, whereas the fermented soybean containing Mucor zygomycetes had many clumps of tissue. In Figures 10 and 11, the clumps are indicated by ellipses. This suggests that the type and presence of zygomycetes influences the formation of clumps of tissue, which in turn influences the physical properties of the fermented soybean, such as viscoelasticity and viscosity.

[0126] Example 9 The effect of JW-1 was further verified by measuring the physical properties of bread. For bread made using leavening agent A in Table 4 above, a breaking strength test and texture analysis were carried out using a creep meter.

[0127] [Breaking strength test] To measure the crumb, which is the inside of the bread, a 10 mm thick piece of bread was used as the test piece, and to measure the crust, which is the skin of the bread, a 3 mm thick piece of bread was used as the test piece. Using a creep meter (Yamaden, RE2-33005S), the stress was measured when the sample broke under the conditions shown below. Detailed measurement conditions are shown in Table 13.

[0128] [Table 13]

[0129] The results of measuring the crumb are shown in Figure 12. In Figures 12 to 15, "JW x 3" indicates that three times the amount of JW-1 was added, and the control indicates that no JW-1 was added. As shown in Figure 12, the maximum load, which corresponds to the stress at the time of biting, was highest for JW, followed by JW x 3, and the control, indicating that the breads with added JW were harder. Furthermore, the stress during breaking, for example, the breaking strength up to a strain rate of 80%, was highest for the 3x JW-1, followed by the 1x JW, and then the control. This indicates that the addition of more JW-1 tends to increase the stress of the crumb, especially at the beginning of biting. These findings suggest that the addition of JW-1 may make bread sturdier and provide a chewier texture, especially at the beginning of biting.

[0130] The results of measuring the crust are shown in Figure 13. As shown in Figure 13, it was clear that the breaking strength was highest for JWx3, which had three times the amount of JW-1 added, followed by the samples with JW-1 added and the control without JW-1 added. The addition of JW-1 increased the hardness of the crust, suggesting that it may be possible to give the bread a firmer crust and a chewy texture when biting into it. Furthermore, the breaking strength of the crust, which is the outer layer of the bread, is significantly higher than that of the crumb, suggesting that the stress experienced when biting into this bread is strongly influenced by the stress experienced when biting into the crust. As described above, it was shown that the breaking strength of bread increases when more Zygomycetes or JW-1 are inoculated, as the stress when the crumb begins to bite increases and the stress of the crust when biting through becomes higher, resulting in an overall harder and chewier texture.

[0131] [Texture Analysis] Furthermore, texture analysis was performed using a creep meter (Yamaden, RE2-33005S) by compressing the sample twice under the following conditions. Detailed measurement conditions are shown in Table 14.

[0132] [Table 14]

[0133] For texture analysis, the following sizes of dough and crumb were used as samples: For the elasticity test, 20 g of dough was used, for the load test, a 10 mm thick dough was used, and for the crumb test, a 30 mm x 30 mm x 30 mm test piece was used.

[0134] The results of the texture analysis of the bread dough are shown in Figure 14. As shown in Figure 14, JWx3 was the hardest, followed by JW, and the control was the softest.

[0135] Table 15 shows the results of dough elasticity.

[0136] [Table 15]

[0137] The results in Table 15 confirm that the addition of JW-1 increases the elasticity of bread dough.

[0138] The results of the texture analysis of the crumb are shown in Figure 15. As shown in Figure 15, JWx3 was the hardest, followed by JW and the control.

[0139] Table 16 shows the results of elasticity, cohesiveness and chewiness derived from this. Regarding elasticity, JW gave a high value, but JW x 3 gave a low value, so a comprehensive evaluation of chewability was carried out taking into account cohesiveness, etc. Elasticity is the ratio of the depression and deformation when compressed twice, hardness is the maximum stress when a load is applied to the sample, and cohesiveness is the ratio of the load area (energy) when compressed twice. Chewability was calculated as "hardness x cohesiveness x elasticity" and was measured as the energy required to make a solid food product ready to be swallowed.

[0140] [Table 16]

[0141] The addition of JW-1 tends to harden the crumb, potentially imparting a chewy texture to bread, but elasticity tends to decrease when JW-1 is added in excess, such as three times the normal amount, and there does not seem to be any correlation with hardness. Therefore, when chewiness was evaluated, taking into account factors such as cohesiveness, chewiness tended to increase with increasing amounts of JW-1 added, suggesting a correlation. Thus, adding zygomycetes such as JW-1 to a leaven resulted in clear changes in the physical properties of the bread produced, suggesting the possibility of developing bread of new quality.

Claims

1. A method for producing a fermented starter, comprising a step of fermenting a mixture containing a zygomycete belonging to the order Mucorales of the phylum Mucorales and a fermentation substrate.

2. The method for producing a fermented starter according to claim 1, wherein the zygomycete is a filamentous fungus and is one or more zygomycetes selected from the genera Mucor, Helicostylum, Rhizopus, Umbelopsis, and Pseudomonas.

3. The method for producing a leaven according to claim 1 or 2, wherein the mixture contains baker's yeast.

4. The method for producing a fermented starter according to claim 1 or 2, wherein the mixture contains lactic acid bacteria.

5. The method for producing a fermented starter according to claim 1 or 2, wherein the fermented starter is a co-fermented product of a zygomycete belonging to the order Mucorales of the phylum Mucorales and a lactic acid bacterium.

6. The method for producing a fermented starter according to claim 1 or 2, wherein the lactic acid bacterium is Lactococcus lactis.

7. A step of obtaining a fermented starter by the method for producing a fermented starter according to claim 1 or 2; preparing bakery dough containing the leaven, and baking the bakery dough to produce the bakery food.

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