Production method of oat soy sauce

Abstract

The invention discloses a production method of oat soy sauce, and belongs to the technical field of fermentation engineering. According to the method, by comparing the influence of replacement of flour by oat flour in different proportions on the contents of functional components, flavor substances and the like in the fermentation of the oat soy sauce, strains which are used for replacing raw materials and releasing the oat functional components most sufficiently are finally selected, and viable bacteria are added into fermented soy sauce mash. When the ratio of the flour to the oat is 7: 3, and the WT-1 is strengthened, the total phenols, the total flavonoids, the organic acids, the amino acids, the color rate, the DPPH clearance rate, the reducing power, the umami amino acids, the sweet amino acids, the red index and the yellow index of the oat soy sauce are respectively improved by 9.7%, 82.2%, 11.0%, 11.5%, 11.7%, 9%, 32.1%, 16.4%, 9.6%, 0.96% and 1.92% on the previous basis. The method has important significance in enhancing release of functional components of the oat soy sauce, increasing the content of flavor substances, improving oxidation resistance and the like.

Description

Technical Field

[0001] The invention relates to a production method of oatmeal soy sauce and belongs to the technical field of fermentation engineering. Background Art

[0002] Soy sauce is a traditional fermented condiment in my country. It is mainly made from soybeans or soybean meal and flour. It is fermented under the action of complex microorganisms and enzyme systems through processes such as koji making and post-fermentation. With the improvement of people's living standards, they are no longer satisfied with "eating enough", but want to eat well and eat healthily. As a condiment, soy sauce not only has the characteristics of bright color, rich aroma and delicious taste, but also contains phenols, flavonoids, polysaccharides and peptides, which can also play physiological roles such as antioxidant, anti-inflammatory and immune regulation. In recent years, many brands on the market have continuously launched various high-end soy sauces for specific groups of people, especially "zero-additive" soy sauce, which is especially popular among consumers because of its pure natural food. With the development of science and technology, the food industry is seeking to improve product quality and market competitiveness through new technologies and methods. Most of the fermented products with special flavors available on the market today achieve their unique flavor, taste and functionality by adding auxiliary materials, and optimize product characteristics by adjusting the fermentation process of auxiliary materials and the use of functional strains. For example, craft beer, flavored yogurt and special flavored vinegar, etc., are loved by consumers in the food and beverage industry for their unique flavor and health benefits.

[0003] Oats are a functional grain that contains a large amount of soluble dietary fiber, essential amino acids, unsaturated fatty acids, polyphenols and flavonoids, and have high nutritional value. Oats' flavonoids, polyphenols and β-glucan are plant-based preservatives, and their antibacterial properties have been reported in many reports. Moreover, there are no serious adverse reactions to the human body after taking such substances. Studies have found that the use of microbial fermentation can not only improve the functional properties of oats, but also open up ways to utilize oat resources. Most of the polyphenols and flavonoids in oats exist in the form of complex insoluble combinations with polysaccharides, proteins or cell walls. In the brewing process of soy sauce, the rich enzyme systems such as amylase, protease, cellulase, ferulic acid esterase and β-glucosidase produced by microorganisms such as Aspergillus oryzae and lactic acid bacteria can decompose and utilize the raw materials, so that the nutrients and functional components in the raw materials are further released and transformed. Using oats as one of the raw materials for brewing soy sauce can increase the functional components of soy sauce and improve the antioxidant and antibacterial properties of soy sauce. In addition, functional strains can be used to fully ferment oat raw materials, improve the quality of soy sauce, and enhance the flavor of soy sauce. Oatmeal brewed soy sauce can meet the market demand for healthy food and has good development prospects.

[0004] Some scholars have studied the addition of other raw materials to brew soy sauce, but most of them are studies on koji making and brewing processes, and there is almost no research on oatmeal soy sauce raw materials. This study adopts a high-salt dilute soy sauce brewing method and adds oats to the soy sauce brewing process to explore the effects of adding oats on the changes in the flora, fermentation quality and flavor in the soy sauce fermentation system, explore the effects of adding oats on the functionality, stability and flavor of soy sauce, and optimize the fermentation process of oatmeal brewing soy sauce, providing new ideas and theoretical references for the preparation of high-quality soy sauce without additives. Summary of the invention

[0005] The invention provides a method for preparing oat brewed soy sauce. The method comprises: taking soybean, flour and oat powder as raw materials, mixing the raw materials and Aspergillus oryzae to prepare koji, and preparing finished koji; mixing the finished koji with salt water, inoculating Pediococcus acidilactici WT1, and performing high-salt dilute fermentation to prepare the soy sauce; and the final concentration of the salt water in the fermentation system is 16-20 g / 100 ml.

[0006] The lactic acid bacteria Pediococcus WT-1 is numbered CGMCC NO.26263, which is recorded in the Chinese invention patent application with publication number CN 116536185A.

[0007] In one embodiment of the present invention, the flour and oatmeal powder are added in a mass ratio of 2-3:8-7, and further, the flour and oatmeal powder are added in a ratio of 7:3;

[0008] In one embodiment of the present invention, the amount of Pediococcus acidilactici WT1 added is at least: 1×10 7 CFU / g;

[0009] In one embodiment of the present invention, the high-salt dilute fermentation conditions are as follows: the brine and the koji material are mixed evenly at a mass ratio of 1.8 to 2:1, so that the final concentration of sodium chloride in the system is 16 to 20 g / 100 mL, and at least 1×10 7 CFU / g of lactic acid bacteria Pediococcus WT-1; after sealing, place in a constant temperature incubator at 28-32°C for fermentation for 40-60 days;

[0010] In one embodiment of the present invention, the conditions for preparing the koji are: environmental humidity 90% to 95%, temperature 28° C. to 30° C.; the koji turning time is 16 h to 24 h, and the koji making operation is terminated when the surface of the koji material is covered with yellow-green spores;

[0011] In one embodiment of the present invention, the raw material is obtained by mixing flour and oatmeal powder in a mass ratio of 2-3:8-7, and then mixing with soybeans in a ratio of 1-4:1-6;

[0012] In one embodiment of the present invention, the Aspergillus oryzae includes but is not limited to Aspergillus oryzae AS3.042 koji essence, which is added in an amount of 1 to 1.6‰ of the total weight of the raw materials.

[0013] In one embodiment of the present invention, the method comprises the following steps:

[0014] (1) Koji making

[0015] Soybeans were mixed with 4 times the weight of water and soaked for 10 hours. After being fully moistened, the water was drained and steamed at 121℃ for 15 minutes (0.1MPa). After cooling at room temperature, the steamed soybeans were mixed with flour at a mass ratio of 6:4, and with oatmeal at a mass ratio of 6:4 and 7:3 respectively according to the group, and 1.6‰ of the total weight of the raw materials was added with Aspergillus oryzae AS3.042 koji. The koji making conditions were 90% humidity and 30℃; the koji turning time was 24 hours, and water was added from time to time. When the surface of the koji material was covered with yellow-green spores, the koji making operation was completed.

[0016] (2) Fermentation

[0017] The saline solution with a sodium chloride content of 20% (w / v) was mixed with the koji material at a mass ratio of 1.8:1 and stirred evenly in a beaker to make the final sodium chloride concentration of the system 18 g / 100 mL. 1×10 7 CFU / g of lactic acid bacteria Pediococcus WT-1. After sealing, place it in a 30℃ constant temperature incubator for fermentation for 35 days. Stir once a day in the early stage of fermentation and once every two or three days in the later stage.

[0018] In one embodiment of the present invention, the preparation method improves the quality of soy sauce, including but not limited to:

[0019] (a) increasing the contents of total phenols, total flavonoids and β-glucan in the oatmeal soy sauce system;

[0020] (b) increasing the reducing sugar, total acid and amino acid nitrogen contents of oatmeal soy sauce;

[0021] (c) improving the antioxidant capacity of oatmeal soy sauce;

[0022] (d) increasing the content of umami amino acids and sweet amino acids in oatmeal soy sauce;

[0023] (e) increasing the content of organic acids in oatmeal soy sauce;

[0024] (f) improving the chromaticity, yellowness index and redness index of oatmeal soy sauce;

[0025] (g) Increase the viscosity of oatmeal sauce.

[0026] In one embodiment of the present invention, the amount of Pediococcus acidilactici WT1 added to the fermentation agent is at least: 1×10 7 CFU / g

[0027] The present invention also provides an application of the Pediococcus acidilactici WT1 in preparing chemicals for improving the color, functional components and flavor of oatmeal soy sauce.

[0028] In one embodiment of the present invention, the method includes raw material processing, koji making, fermentation, and soy sauce extraction; the above-mentioned Pediococcus acidilactici WT1 or the microbial agent or the fermentation agent is added on the 0th day from the beginning of fermentation.

[0029] The present invention also provides an application of the Pediococcus acidilactici WT1 or the microbial agent or the fermentation agent in the preparation of oatmeal soy sauce.

[0030] The present invention also provides an oat-brewed soy sauce, which is prepared according to the following method:

[0031] Soybean, flour and oatmeal powder are used as raw materials, and the raw materials and Aspergillus oryzae are mixed to make koji to obtain finished koji; the finished koji is evenly mixed with salt water, and then inoculated with Pediococcus acidilactici WT1 for high-salt dilute fermentation to obtain the finished koji; the final concentration of the salt water in the fermentation system is 16-20g / 100ml, and the flour and oatmeal powder are added in an amount of 2-3:8-7 by mass ratio.

[0032] In one embodiment of the present invention, the amount of Pediococcus acidilactici WT1 added is at least: 1×10 7 CFU / g;

[0033] In one embodiment of the present invention, the high-salt dilute fermentation conditions are as follows: the brine and the koji material are mixed evenly at a mass ratio of 1.8 to 2:1, so that the final concentration of sodium chloride in the system is 16 to 20 g / 100 mL, and at least 1×10 7 CFU / g of lactic acid bacteria Pediococcus WT-1; after sealing, place in a constant temperature incubator at 28-32°C for fermentation for 40-60 days;

[0034] In one embodiment of the present invention, the conditions for preparing the koji are: environmental humidity 90% to 95%, temperature 28° C. to 30° C.; the koji turning time is 16 h to 24 h, and the koji making operation is terminated when the surface of the koji material is covered with yellow-green spores;

[0035] In one embodiment of the present invention, the raw material is obtained by mixing flour and oatmeal powder in a mass ratio of 2-3:8-7, and then mixing with soybeans in a ratio of 1-4:1-6;

[0036] In one embodiment of the present invention, the Aspergillus oryzae includes but is not limited to Aspergillus oryzae AS3.042 koji, which is added at 1-1.6‰ of the total weight of the raw materials;

[0037] In one embodiment of the present invention, the flour and oatmeal powder are added in a ratio of 7:3.

[0038] The present invention also provides a method for improving the viscosity, antioxidant property, color and flavor of oatmeal soy sauce, wherein oats are used as raw materials to prepare koji, and Pediococcus acidilactici WT1 is added to the prepared koji to perform high-salt dilute fermentation; specifically comprising:

[0039] Soybean, flour and oatmeal powder are used as raw materials, and the raw materials and Aspergillus oryzae are mixed to make koji to obtain finished koji; the finished koji is mixed with salt water, and then inoculated with Pediococcus acidilactici WT1 to perform high-salt dilute fermentation; the final concentration of salt water in the fermentation system is 16-20g / 100ml, and the flour and oatmeal powder are added in an amount of 2-3:8-7 by mass ratio.

[0040] In one embodiment of the present invention, the amount of Pediococcus acidilactici WT1 added is at least: 1×10 7 CFU / g;

[0041] In one embodiment of the present invention, the high-salt dilute fermentation conditions are as follows: the brine and the koji material are mixed evenly at a mass ratio of 1.8 to 2:1, so that the final concentration of sodium chloride in the system is 16 to 20 g / 100 mL, and at least 1×10 7 CFU / g of lactic acid bacteria Pediococcus WT-1; after sealing, place in a constant temperature incubator at 28-32°C for fermentation for 40-60 days;

[0042] In one embodiment of the present invention, the conditions for preparing the koji are: environmental humidity 90% to 95%, temperature 28° C. to 30° C.; the koji turning time is 16 h to 24 h, and the koji making operation is terminated when the surface of the koji material is covered with yellow-green spores;

[0043] In one embodiment of the present invention, the raw material is obtained by mixing flour and oatmeal powder in a mass ratio of 2-3:8-7, and then mixing with soybeans in a ratio of 1-4:1-6;

[0044] In one embodiment of the present invention, the Aspergillus oryzae includes but is not limited to Aspergillus oryzae AS3.042 koji, which is added at 1-1.6‰ of the total weight of the raw materials;

[0045] In one embodiment of the present invention, the flour and oatmeal powder are added in a ratio of 7:3.

[0046] The present invention also provides an application of synergistic fermentation of Pediococcus acidilactici WT1 and oat / flour mixture raw material in improving the content of total flavonoids, total phenols and β-glucan in soy sauce prepared by fermentation using oats as raw materials.

[0047] In one embodiment of the present invention, oats are used as raw materials to prepare koji, and lactic acid Pediococcus WT1 is added to the prepared koji to perform high-salt dilute fermentation; specifically, the process comprises: using soybean, flour, and oatmeal powder as raw materials, mixing the raw materials and Aspergillus oryzae to prepare koji; mixing the obtained koji with salt water, inoculating lactic acid Pediococcus WT1, and performing high-salt dilute fermentation; the final concentration of salt water in the fermentation system is 16-20 g / 100 ml, and the flour and oatmeal powder are added in an amount of 2-3:8-7 by mass ratio.

[0048] In one embodiment of the present invention, the amount of Pediococcus acidilactici WT1 added is at least: 1×10 7 CFU / g;

[0049] In one embodiment of the present invention, the high-salt dilute fermentation conditions are as follows: the brine and the koji material are mixed evenly at a mass ratio of 1.8 to 2:1, so that the final concentration of sodium chloride in the system is 16 to 20 g / 100 mL, and at least 1×10 7 CFU / g of lactic acid bacteria Pediococcus WT-1; after sealing, place in a constant temperature incubator at 28-32°C for fermentation for 40-60 days;

[0050] In one embodiment of the present invention, the conditions for preparing the koji are: environmental humidity 90% to 95%, temperature 28° C. to 30° C.; the koji turning time is 16 h to 24 h, and the koji making operation is terminated when the surface of the koji material is covered with yellow-green spores;

[0051] In one embodiment of the present invention, the raw material is obtained by mixing flour and oatmeal powder in a mass ratio of 2-3:8-7, and then mixing with soybeans in a ratio of 1-4:1-6;

[0052] In one embodiment of the present invention, the Aspergillus oryzae includes but is not limited to Aspergillus oryzae AS3.042 koji, which is added at 1-1.6‰ of the total weight of the raw materials;

[0053] In one embodiment of the present invention, the flour and oatmeal powder are added in a ratio of 7:3.

[0054] Beneficial Effects

[0055] (1) The present invention replaces the flour in the soy sauce fermentation raw materials with oat flour in different proportions to obtain the optimal oat flour replacement ratio for making oat soy sauce. Compared with the soy sauce brewed from traditional pure flour raw materials, the DPPH clearance rate and reducing power of the brewed oat soy sauce are increased by 4.18% and 20.7% respectively, the viscosity is 1.69Pa·s, increased by 33%, the contents of total flavonoids, total phenols and β-glucan are increased by 34.3%, 11.1% and 31.8%; the amino acid nitrogen content is increased by 8.4% compared with the control group, the total organic acid content is 21.08g / L, increased by 7.7% compared with the control group, the succinic acid content is 5.17g / L, increased by 27.1% compared with the control group, and the tartaric acid content is 0.306g / L, increased by 13.3% compared with the control group. The umami amino acid is increased by 12.2% compared with the control group, which is the most significant increase; the sweet amino acid is increased by 9.23%.

[0056] (2) The present invention screened out a functional lactic acid bacterium Pediococcus acidilacticii WT1 from existing strains, which has the best strain characteristics and fermentation ability under a certain salinity and can cooperate with oatmeal soy sauce fermentation. By strengthening Pediococcus acidilacticii WT1 at the optimal fermentation ratio of soybean and oatmeal powder, compared with the soy sauce brewed from traditional pure flour raw materials, the DPPH clearance rate and reducing power increased by 9% and 32.1% respectively compared with the control group, the viscosity was 1.61 Pa·s, increased by 26%, the total flavonoids, total phenols and β-glucan contents increased by 82.2%, 9.6% and 102% respectively; the amino acid nitrogen content increased by 11.6% compared with the control group, the total organic acid content was 22.73 g / L, increased by 11.0% compared with the control group, the succinic acid content was 5.87 g / L, increased by 18.2% compared with the control group, and the tartaric acid content was 0.265 g / L, increased by 55.9% compared with the control group. The umami amino acids increased by 16.4% compared with the control group, which was the most significant increase; the sweet amino acids increased by 9.6%. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] Figure 1 This is a graph showing the changes in total acid content and amino acid nitrogen content during the fermentation process when replacing oat raw materials in different proportions.

[0058] Figure 2 Changes in reducing sugar content during fermentation when oat raw materials are replaced in different proportions.

[0059] Figure 3 The performance of 8 different lactic acid bacteria strains is compared, among which (a) is salt tolerance, (b) is ferulic acid esterase activity, and (c) is β-glycosidase activity.

[0060] Figure 4 The total flavonoids content and total phenol content obtained by 8 different lactic acid bacteria under simulated fermentation.

[0061] Figure 5 The β-glucan content obtained by 8 different lactic acid bacteria under simulated fermentation conditions.

[0062] Figure 6 The changes in acid and amino nitrogen content during the fermentation process were analyzed by changing the raw material ratio and adding functional strains; (a) is the change in total acid content, and (b) is the change in amino acid nitrogen content.

[0063] Figure 7 To change the raw material ratio and add functional strains during the fermentation process + reducing sugar content changes. DETAILED DESCRIPTION

[0064] The sources of the 8 lactic acid bacteria involved in the following embodiments are: E. faecium D1, E. faecium T1, P. acidilactici WT1, P. acidilactici ZQ1, P. pentosaceus WT6, P. pentosaceus WT8, disclosed in Wang Tao. Screening of functional lactic acid bacteria and its application in low-salt solid soy sauce fermentation [D]. Jiangnan University, 2023 paper. L. plantarum JL-20, L. plantarum JP31, disclosed in Li Jialian. Probiotic properties of salt-tolerant lactic acid bacteria and their application in food fermentation [D]. Jiangnan University, 2023 paper.

[0065] The Aspergillus oryzae Shanghai Brewing 3.042 involved in the following examples was purchased from Shanghai Difa Brewing Biological Products Co., Ltd., the high temperature α-amylase was purchased from Shandong Longkote Enzyme Preparation Co., Ltd., the saccharifying enzyme was purchased from Jiangsu Ruiyang Biotechnology Co., Ltd., and the neutral protease was purchased from Henan Wanbang Chemical Technology Co., Ltd.

[0066] The lactic acid bacteria Pediococcus WT-1 involved in the following examples is described in the Chinese invention patent application with publication number CN 116536185 A.

[0067] The culture medium involved in the following examples is as follows:

[0068] MRS medium: peptone 10g / L, beef extract powder 8g / L, yeast extract powder 4g / L, glucose 20g / L, dimethyl phosphate 2g / L, diammonium hydrogen citrate 2g / L, sodium acetate 5g / L, magnesium sulfate 0.2g / L, manganese sulfate 0.04g / L, Tween 80 1g / L.

[0069] The detection methods involved in the following embodiments are as follows:

[0070] DPPH free radical scavenging rate

[0071] Experimental group: 1 mL of sample diluent was added with 1 mL of 200 μM / L DPPH ethanol solution, mixed and reacted for 30 min in the dark;

[0072] Control group: 1 mL of sample diluent and 1 mL of anhydrous ethanol were mixed;

[0073] Blank group: 1 mL of deionized water and 1 mL of anhydrous ethanol were mixed. The absorbance measurement wavelength was 517 nm. DPPH free radical scavenging rate = [1-(absorbance of experimental group-absorbance of control group) / absorbance of blank group] × 100%.

[0074] Determination of reducing power

[0075] Take 1mL of sample diluent, mix with 2.5mL of PBS solution (pH=6.6), 2.5mL of 1% potassium ferricyanide solution, react at 50℃ for 20min, add 2.5mL of 10% TCA solution, centrifuge at 5000r / min for 10min, take 2.5mL of supernatant, add 2.5mL of deionized water and 0.5mL of 1% ferric chloride solution in sequence, mix well and place at room temperature for 10min, the absorbance measurement wavelength is 700nm. The reducing power of the sample is expressed by Trolox content, and the Trolox standard curve is y=3.946x+0.034(R 2 =0.995).

[0076] Determination of soy sauce viscosity

[0077] The viscosity analysis of soy sauce samples was performed using a TA HR10 rheometer (40 mm diameter parallel plate, TA Instruments, USA) with a gap setting of 0.5 mm. Amplitude sweeps (0.1-100%, 10 rad / s) and viscosity measurements (shear rate 0.01-100) were performed at 25 °C.

[0078] Determination of Soy Sauce Color

[0079] Take 2g of mash in a 5mL centrifuge tube and centrifuge at 12000r / min. -1 Centrifuge for 5 minutes. Take the supernatant and filter it through a 0.45 μm filter membrane. Dilute it 10 times and measure its absorbance at 420, 460, 510, and 610 nm, and calculate it according to formula (1)-formula (3).

[0080]

[0081] Determination of reducing sugar content

[0082] Take 0.5 mL of diluent, add 0.5 mL of DNS reagent and mix well, boil for 10 min, cool and dilute to 5 mL with deionized water, mix well and measure the absorbance at a wavelength of 540 nm.

[0083] The standard curve of reducing sugar is y = 0.0009x-0.0383 (R 2 =0.9998).

[0084] Total acid and amino acid nitrogen content

[0085] According to GB 5009.235-2016, the total acid content is calculated by sodium hydroxide titration; the content of amino acid nitrogen in the sauce mash is calculated by formaldehyde titration.

[0086] Determination of organic acid and free amino acid content

[0087] The free amino acid and organic acid contents were detected by high performance liquid chromatography, and the specific conditions are shown in Tables 1 and 2, respectively.

[0088] Table 1: HPLC method used for free amino acid detection

[0089]

[0090] Table 2: HPLC determination conditions for organic acid content

[0091]

[0092]

[0093] Determination of total phenolic content:

[0094] After 1mL of sample diluent was mixed with 4.5mL of deionized water, 500μL of Folin phenol reagent was added, and the mixture was allowed to stand at room temperature for 10min. 4mL of 7.5% (w / v) Na2CO3 solution was added, and the mixture was allowed to stand in the dark for 2h after mixing. The absorbance measurement wavelength was 765nm. The gallic acid standard curve was y=0.009x+0.0127(R 2 =0.9979).

[0095] Determination of total flavonoids content:

[0096] Dilute the sample with methanol to an appropriate multiple, centrifuge at 8000r / min for 15min, take 1mL of the supernatant and mix it with 4mL of 70% ethanol and 0.3mL of 5% NaNO2 solution, and let it stand for 5min. Then add 0.3mL of 10% Al(NO3)3 solution, mix it and let it stand for 6min. Then add 4mL of 1mol / L NaOH solution and 0.4mL of 30% ethanol solution, mix it and let it stand for 10min. The absorbance measurement wavelength is 510nm. Rutin standard curve y=1.1657x+0.0025(R 2 =0.9999).

[0097] Example 1: Effect of different proportions of oat raw material replacement fermentation on the properties of oat soy sauce

[0098] The specific steps are as follows:

[0099] (1) Koji making

[0100] Soybeans were mixed with 4 times the weight of water and soaked for 10 hours. After being fully moistened, the water was drained and steamed at 121℃ for 15 minutes (0.1MPa). After cooling at room temperature, the steamed soybeans were mixed with flour at a mass ratio of 6:4 (wherein the flour was partially replaced with oatmeal flour to set different groups, and the replacement ratio was 5:5, 6:4, and 7:3) according to the group, and 1.6‰ of the total weight of the raw materials was inoculated with Aspergillus oryzae AS3.042 koji. The koji making conditions were 90% humidity and 30℃; the koji turning time was 24 hours, and water was added from time to time. When the surface of the koji material was covered with yellow-green spores, the koji making operation was terminated. The koji making time was: 44 to 48 hours.

[0101] The specific group settings are as follows: CK is the control group, that is, the mass ratio of soybean to flour in the fermentation raw materials is 6:4; Oat (5:5), Oat (6:4), and Oat (7:3) are the experimental groups, which replace flour with oatmeal flour on the basis of the ratio of the control group, and the replacement ratios are 50%, 60%, and 70%, respectively.

[0102] The details are as follows:

[0103] CK: Do not replace flour, mix the steamed soybeans and flour in a mass ratio of 6:4;

[0104] Oat (5:5): replace flour with oat flour in a mass ratio of 5:5, and mix the steamed soybeans with the replaced mixture in a mass ratio of 6:4;

[0105] Oat (6:4): replace flour with flour and oat flour in a mass ratio of 6:4, and mix the steamed soybeans with the replaced mixture in a mass ratio of 6:4;

[0106] Oat (7:3): Replace flour with flour and mix oat flour in a mass ratio of 7:3. Mix the steamed soybeans with the replaced mixture in a mass ratio of 6:4.

[0107] (2) Fermentation

[0108] Mix the salt water with a sodium chloride content of 20% (w / v) with the koji obtained in step (1) at a mass ratio of 1.8:1, and stir evenly in a beaker to make the final sodium chloride concentration of the system 18g / 100mL. After sealing, place it in a 30℃ constant temperature incubator for fermentation for 35 days. Stir once a day in the early stage of fermentation and once every two or three days in the later stage. Take a sample every 5 days.

[0109] The result is as follows:

[0110] 1) Effect of different proportions of oat raw material replacement on the antioxidant activity and viscosity of soy sauce

[0111] Table 3: Effect of different proportions of oat raw material replacement on the antioxidant activity of soy sauce

[0112]

[0113] Table 4: Effect of different proportions of oat raw material replacement on soy sauce viscosity

[0114]

[0115] The results showed that with the increase of replacement ratio, DPPH scavenging rate and reducing power gradually increased, and the viscosity of soy sauce increased. Among them, Oat (7:3) was the most significant, with DPPH scavenging rate and reducing power of 86.33% and 2.39mM Trolox / mL, which increased by 4.18% and 20.7% respectively compared with the control group, and the viscosity was 1.69Pa·s, which increased by 33%. The DPPH scavenging rate and reducing power of Oat (5:5) and Oat (6:4) increased by 0.98% and 5.1%, 3.12% and 8.1% respectively compared with the control group, and the viscosity increased by 14.2% and 15.7%. This shows that increasing the addition ratio of oat flour improves the antioxidant property of fermented soy sauce, and also promotes the texture and fermentation degree of soy sauce.

[0116] 2) Effects of different proportions of oat raw material replacement on the contents of total phenols, total flavonoids and glucan during soy sauce fermentation

[0117] Table 5: Comparison of functional component contents in each group

[0118]

[0119] The results showed that with the increase of the replacement ratio of oat flour, the content of total flavonoids, total phenols and β-glucan related to oats in soy sauce was improved. The total flavonoids content of Oat (5:5), Oat (6:4) and Oat (7:3) was 120.5mg / L, 139.2mg / L and 150.6mg / L, which increased by 7.5%, 24.3% and 34.3% compared with the control group, and the total phenol content of Oat (7:3) increased by 11.1% compared with the control group. The β-glucan content was 4.41g / L, 4.04g / L and 3.43g / L, which increased by 69.7%, 55.4% and 31.8% compared with the control group. This shows that the addition of oat flour can effectively increase the content of functional components in soy sauce and improve the nutritional value of soy sauce.

[0120] 3) Effects of different proportions of oat raw material replacement on the contents of amino acid nitrogen, total acid, reducing sugar, free amino acids and organic acids during soy sauce fermentation

[0121] Changes of total acid and amino acid nitrogen during fermentation Figure 1 shown.

[0122] The results showed that at the end of fermentation, the total acid content of Oat (7:3) was 5.3275g / L, which was 2.4% higher than that of the control group, and the amino acid nitrogen content was 0.4g / 100ml, which was 8.4% higher than that of the control group. The total acid of Oat (5:5) and Oat (6:4) was 4.805g / L and 5.0925g / L, which was 7.7% and 2.1% lower than that of the control group, and the amino acid nitrogen content was 0.318g / 100ml and 0.365g / 100ml, which was 14.1% and 1.3% lower than that of the control group. This shows that replacing flour with oat flour has an impact on the fermentation quality of soy sauce. Only when the replacement ratio is above 60%, the total acid and amino acid nitrogen in soy sauce can be increased, and the quality of fermented soy sauce can be improved.

[0123] Changes of reducing sugars during fermentation Figure 2 shown.

[0124] The results showed that the reducing sugar content of Oat (5:5), Oat (6:4) and Oat (7:3) at the end of fermentation was 32.28019 g / L, 25.05666 g / L and 18.5492 g / L respectively, which increased by 2.92 times, 4.45 times and 3.45 times compared with the start of fermentation. This shows that a high proportion of oat replacement will reduce the initial sugar content.

[0125] Organic acids were determined by HPLC

[0126] Use ultrapure water to dilute 5 mL of the mash supernatant 10 times and filter it through a 0.22 μm filter membrane before testing.

[0127] Table 6: Comparison of organic acid content in each group

[0128]

[0129] Organic acids are important components of the flavor of soy sauce. Succinic acid and its sodium salt can adjust the saltiness and increase the umami flavor of soy sauce, while tartaric acid can enhance the mellowness of soy sauce.

[0130] The results showed that the addition of oat flour can increase the organic acid content in soy sauce. The total organic acid content of Oat (5:5), Oat (6:4) and Oat (7:3) were 19.94g / L, 20.49g / L and 21.08g / L, respectively, which were 1.8%, 4.7% and 7.7% higher than those of the control group. The succinic acid content of Oat (7:3) was 5.17g / L, which was 27.1% higher than that of the control group, and the tartaric acid content was 0.306g / L, which was 13.3% higher than that of the control group.

[0131] Free amino acids were determined by HPLC

[0132] O-xylene (OPA) was used for in-column derivatization. The supernatant of the mash (obtained by centrifugation of mash at 12000 r / min for 30 min) was diluted 20 times with 5% trichloroacetic acid and treated for 1 h, and 1 mL of the sample was taken for testing after filtering through a 0.22 μm water filter membrane.

[0133] Table 7: Comparison of amino acid content in each group

[0134]

[0135] The results showed that the total amount of amino acids in soy sauce fermented with Oat (6:4) and Oat (7:3) was 40.5g / L and 42.74g / L, which was 2.8% and 8.49% higher than that of the control group.

[0136] Aspartic acid and glutamic acid are the main umami substances in soy sauce. The total amount of umami amino acids in the Oat (7:3) fermentation group was 12.18 g / L, which was 12.2% higher than that in the control group, the most significant increase; the sweet amino acids increased by 9.23%.

[0137] The above results show that increasing the replacement ratio of oats can significantly increase the content of umami amino acids and sweet amino acids in soy sauce, and increase the content of flavor substances in soy sauce.

[0138] Example 2: Screening of functional strains for synergistic fermentation of oats and soy sauce

[0139] 1. This section mainly describes the comparison of different target lactic acid bacteria in terms of salt tolerance, ferulic acid esterase activity, glycosidase activity and other indicators related to the release of oat functional components; the specific process is as follows:

[0140] (1) Analysis of salt resistance characteristics:

[0141] Single colonies on culture dishes of 8 strains of lactic acid bacteria (E. faecium D1, E. faecium T1, P. acidilactici WT1, P. acidilactici ZQ1, P. pentosaceus WT6, P. pentosaceus WT8, L. plantarum JL-20, L. plantarum JP31) including lactic acid bacteria Pediococcus WT-1 were inoculated into MRS liquid culture medium and cultured at 37°C for 10-12 h to the logarithmic growth phase. The lactic acid bacteria were inoculated into fresh MRS liquid culture medium containing 18% NaCl at an inoculum size of 2% (v / v), and the absorbance at 600 nm was measured after static culture at 37°C for 12 h.

[0142] The results of salt tolerance analysis are as follows: Figure 3 As shown in (a), the results show that the survival rates of the three bacteria, E. faecium D1, P. acidilactici WT1, and P. pentosaceus WT6, in the culture medium containing 18% NaCl are all above 70%, indicating that these bacteria can act on the soy sauce fermentation system.

[0143] (2) Ferulic acid esterase activity analysis:

[0144] Eight strains of lactic acid bacteria (E. faecium D1, E. faecium T1, P. acidilactici WT1, P. acidilactici ZQ1, P. pentosaceus WT6, P. pentosaceus WT8, L. plantarum JL-20, L. plantarum JP31) were cultured in MRS liquid medium at 37°C for 12 h to the logarithmic growth phase, and the cells were collected by centrifugation at 3000g for 5 min, washed with 0.85% saline, resuspended in deionized water, inoculated with 2% (v / v) inoculum in MRS medium containing 1% mass fraction of ethyl ferulate, fermented at 30°C for 48 h, and then 1 ml of the fermentation broth was centrifuged at 12000g for 2 min. The supernatant was taken and stored in the dark. Ferulic acid was detected by HPLC. Chromatographic conditions: ODS HYPERSIL (250 mm×4.6 mm×5 μm), mobile phase A methanol-B 1% glacial acetic acid (28:72), column temperature 40°C, detection wavelength 320 nm, injection volume 10 μL.

[0145] Ferulic acid esterase activity analysis results Figure 3 As shown in (b), the results showed that P. acidilactici WT1 and P. acidilactici ZQ1 had the highest ferulic acid esterase activities, which were 5.33U / ml and 5.77U / ml, respectively.

[0146] (3) β-Glucosidase activity analysis:

[0147] Eight lactic acid bacteria strains (E. faecium D1, E. faecium T1, P. acidilactici WT1, P. acidilactici ZQ1, P. pentosaceus WT6, P. pentosaceus WT8, L. plantarum JL-20, L. plantarum Single colonies on a culture dish of JP31) were inoculated into MRS liquid medium and cultured at 37°C for 10-12h to the logarithmic growth phase. Lactobacillus was inoculated into fresh MRS liquid medium at an inoculum amount of 2% (v / v). After static culture at 37°C for 12h, 100 μL of the supernatant of the culture broth of 8 strains of lactic acid bacteria was taken from each of them, and 1.8mL of acetic acid-sodium acetate buffer with pH=5.0 was added to a clean test tube. A test tube in which 100 μL of buffer was added instead of the crude enzyme solution was used as a blank control. The two groups were treated in a 37°C constant temperature water bath for 5min, and then 100 μL of 20mmol / L reaction substrate p-nitrobenzene-β-D-glucoside was added. After reacting for 10min, 1mL of 1mol / L sodium carbonate solution was added to terminate the reaction. After cooling to room temperature, the absorbance of the reaction solution was measured at 400nm.

[0148] The results of β-glucosidase activity analysis were as follows Figure 3 (c) as shown.

[0149] The results showed that P. acidilactici WT1 and P. pentosaceus WT6 had the highest β-glycosidase activities, which were 11.45U / ml and 11.17U / ml, respectively.

[0150] The above results show that P. acidilactici WT1 is the strain that has good enzyme activity characteristics in a high-salt environment among the strains studied, and has the potential for synergistic fermentation function. Therefore, the strains studied will continue to be evaluated from the perspective of fermentation function.

[0151] 2. The actual fermentation ability of each strain related to the release of oat functional components under simulated fermentation conditions was compared. The specific process is as follows:

[0152] (1) Oat simulated fermentation medium:

[0153] The oat flour raw material was passed through a 100-mesh sieve, mixed at a material-water ratio of 1:5, and then 83.3 U / ml high-temperature α-amylase was added, heated in a 94°C water bath for 1 hour, and then 166.7 U / ml saccharifying enzyme and 83.3 U / ml neutral protease were added, reacted in a 60°C constant temperature water bath for 30 minutes, and then sterilized and enzyme-inactivated at 105°C for 5 minutes to obtain an oat simulated fermentation medium.

[0154] (2) Simulated fermentation:

[0155] The oat simulated fermentation medium was mixed with 18% saline in a ratio of 1:1, and then lactic acid bacteria were added at a volume of 2% (v / v) to make the initial fermentation bacteria concentration in the oat slurry 10 7 CFU / g, and cultured statically at 37°C for 48h to obtain the sample.

[0156] The method for culturing the lactic acid bacteria is as follows:

[0157] Single colonies of E. faecium D1, E. faecium T1, P. acidilactici WT1, P. acidilactici ZQ1, P. pentosaceus WT6, P. pentosaceus WT8, L. plantarum JL-20, and L. plantarum JP31 on culture dishes were inoculated into MRS liquid culture medium, cultured at 37° C. for 10-12 h until the logarithmic growth phase to obtain culture solution, and the culture solution was centrifuged at 4° C. and 8000 rpm for 2 min to obtain bacterial cells, thereby preparing lactic acid bacteria cells.

[0158] Group setting: The control group was the original oat fermentation simulation medium without adding strains, and each experimental group was named according to the inoculated strain.

[0159] The obtained samples were tested for total phenols and total flavonoids. The results of total phenols and total flavonoids were as follows: Figure 4 The results of glucan content are shown in Figure 5 shown.

[0160] The results showed that P.acidilactici WT1 had the best fermentation capacity under simulated fermentation conditions. At the end of fermentation, the total phenol content of this group was 253.1 g / L, an increase of 59.3% compared with the control group; the total flavonoids content was 349.5 g / L, an increase of 710% compared with the control group; and the glucan content was 1.76 g / L, an increase of 154% compared with the control group.

[0161] The above results show that P.acidilactici WT1 is the strain that can exert the best fermentation performance in a high-salt environment. At the same time, it has a strong synergistic ability for the release of functional components in oats. Therefore, it is considered to use P.acidilactici WT1 for synergistic fermentation in the subsequent oat soy sauce fermentation to improve the physicochemical indicators and flavor content of oat soy sauce, thereby improving the quality and flavor of soy sauce.

[0162] Example 3: Effects of adding functional strains and changing the ratio on oatmeal soy sauce

[0163] This section mainly describes the effects of adding functional strains to fermentation raw materials at a ratio of flour: oatmeal = 6:4, flour: oatmeal = 7:3, and 7:3 on the changes in the soy sauce fermentation process.

[0164] The specific steps are as follows:

[0165] (1) Koji making

[0166] Soybeans were mixed with 4 times the weight of water and soaked for 10 hours. After being fully moistened, the water was drained and steamed at 121℃ for 15 minutes (0.1MPa). After cooling at room temperature, the steamed soybeans were mixed with flour or flour / oatmeal mixture at a mass ratio of 6:4 according to the group, and 1.6‰ of the total weight of the raw materials was inoculated with Aspergillus oryzae AS3.042 koji. The koji making conditions were 90% humidity and 30℃; the koji turning time was 24 hours, and water was added from time to time. When the surface of the koji material was covered with yellow-green spores, the koji making operation was terminated. The koji making time was: 44-48 hours.

[0167] The flour / oatmeal mixture is: flour and oatmeal are mixed in a mass ratio of 6:4, or flour and oatmeal are mixed in a mass ratio of 7:3;

[0168] (2) Fermentation

[0169] The saline solution with a sodium chloride content of 20% (w / v) was mixed with the koji material at a mass ratio of 1.8:1 and stirred evenly in a beaker to make the final sodium chloride concentration of the system 18 g / 100 mL. 1×10 7 CFU / g of lactic acid bacteria Pediococcus WT-1. After sealing, place in a 30℃ constant temperature incubator for fermentation for 35 days. Stir once a day in the early stage of fermentation and once every two or three days in the later stage. Take a sample every 5 days.

[0170] Group setting: CK was the control group, that is, the mass ratio of soybean to flour in the fermentation raw materials was 6:4; 6:4, 7:3, and 7:3-WT1 were the experimental groups.

[0171] The details are as follows:

[0172] CK: Do not replace flour, mix the steamed soybeans and flour in a mass ratio of 6:4;

[0173] CK-WT1: Instead of replacing flour, the steamed soybeans were mixed with flour at a mass ratio of 6:4, and 1×10 7 CFU / g of lactic acid bacteria Pediococcus WT-1;

[0174] 6:4: replace the flour with flour and mix the flour and oatmeal in a mass ratio of 6:4, and evenly mix the steamed soybeans with the replaced mixture in a mass ratio of 6:4;

[0175] 7:3: Replace the flour with flour and oatmeal flour in a mass ratio of 7:3, and mix the steamed soybeans with the replaced mixture in a mass ratio of 6:4.

[0176] 7:3-WT1: Flour was replaced with flour and oatmeal was mixed in a mass ratio of 7:3. The steamed soybeans were mixed with the replaced mixture in a mass ratio of 6:4. At the same time, 1×10 7 CFU / g of lactic acid bacteria Pediococcus WT-1;

[0177] After fermentation, the test results are as follows.

[0178] 1) Effects of adding functional strains and changing the ratio on the content of total phenols, total flavonoids and glucan during oatmeal soy sauce fermentation

[0179] Table 8: Comparison of functional component contents in each group

[0180]

[0181] The results showed that the contents of total flavonoids, total phenols and β-glucan, the functional components related to oats in soy sauce, were improved. The total flavonoids contents of 6:4, 7:3 and 7:3-WT1 were 165.2 mg / L, 173.3 mg / L and 228.9 mg / L, which were 31.4%, 37.8% and 82.2% higher than those in the control group. The total phenol contents were 1.72 g / L, 1.89 g / L and 2.0 g / L, and the β-glucan contents were 4.46 g / L, 3.75 g / L and 4.01 g / L, which were 125%, 89.3% and 102% higher than those in the control group.

[0182] Among them, the content of total flavonoids in the 7:3 group increased by 47.61 mg / L compared with the CK group, the CK-WT1 group increased by 24.66 mg / L compared with the CK group, and the 7:3-WT group increased by 103.25 mg / L compared with the CK group. It can be seen that the content of flavonoids in the 7:3-WT group increased relative to the CK group, which was greater than the sum of the contents of flavonoids in the 7:3 group and the CK-WT1 group relative to the CK group (103.25>24.66+47.61). Therefore, the addition of bacterial agent (WT-1) and the change of raw material composition (the mass ratio of flour to oatmeal flour is 7:3) have a synergistic effect.

[0183] In terms of the total phenol content, the 7:3 group increased by 0.071 g / L compared with the CK group, the CK-WT1 group increased by 0.020 g / L compared with the CK group, and the 7:3-WT group increased by 0.176 g / L compared with the CK group. It can be seen that the total phenol content increased in the 7:3-WT group compared with the CK group is greater than the sum of the total phenol content increased in the 7:3 group and the CK-WT1 group compared with the CK group (0.176>0.071+0.020). Therefore, the addition of bacterial agent (WT-1) and the change of raw material composition (the mass ratio of flour to oatmeal flour is 7:3) have a synergistic effect.

[0184] In terms of β-glucan content, the 7:3 group increased by 1.77 g / L, the CK-WT1 group increased by 0.562 g / L, and the 7:3-WT group increased by 2.481 g / L relative to the CK group. It can be seen that the total phenol content increased in the 7:3-WT group relative to the CK group is greater than the sum of the total phenol content increased in the 7:3 group and the CK-WT1 group relative to the CK group (2.481>1.770+0.562). Therefore, adding bacterial agents (WT-1) and changing the raw material composition (the mass ratio of flour to oatmeal flour is 7:3) have a synergistic effect on increasing the β-glucan content.

[0185] This shows that the addition of oat flour can effectively increase the content of functional components in soy sauce and improve the nutritional value of soy sauce. At the same time, the synergistic fermentation of WT1 strain can significantly enhance the release of functional components during the fermentation process of oat soy sauce.

[0186] 2) Effects of adding functional strains and changing the ratio on the viscosity of soy sauce

[0187] Table 9: Effect of WT1 co-fermentation on the viscosity of oatmeal soy sauce

[0188]

[0189] The results showed that the addition of oats and the synergy of functional strains increased the viscosity of soy sauce. The viscosities of 7:3 and 7:3-WT1 were 1.53 Pa·s and 1.61 Pa·s, respectively, which were 13.3% and 26% higher than those of the control group.

[0190] In terms of viscosity, the viscosity of the 7:3 group increased by 0.18, the viscosity of the CK-WT1 group increased by 0.05, and the viscosity of the 7:3-WT group increased by 0.26 relative to the CK group. It can be seen that the viscosity of the 7:3-WT group increased relative to the CK group, which was greater than the sum of the viscosity of the 7:3 group and the CK-WT1 group relative to the CK group (0.26>0.05+0.18). Therefore, the addition of bacterial agent (WT-1) and the change of raw material composition (the mass ratio of flour to oatmeal flour was 7:3) had a synergistic effect.

[0191] 3) Effects of adding functional strains and changing the ratio on the contents of amino acid nitrogen, total acid, reducing sugar, free amino acids and organic acids during soy sauce fermentation

[0192] Changes of total acid and amino acid nitrogen during fermentation Figure 6 Shown

[0193] The results showed that at the end point of fermentation, the total acid contents of 7:3 and 7:3-WT1 were 5.425 g / L and 5.92 g / L, respectively, which were 4.8% and 14.4% higher than those of the control group; the amino acid nitrogen contents were 0.459 g / 100 ml and 0.4795 g / 100 ml, respectively, which were 7% and 11.6% higher than those of the control group; the total acid of 6:4 was 5.2 g / L, with no significant change in total acid compared with the control group; and the amino acid nitrogen content was 0.425 g / 100 ml, which was 1% lower than that of the control group.

[0194] This shows that replacing flour with oatmeal powder has an impact on the fermentation quality of soy sauce. When the ratio of soybean to oatmeal powder is 7:3, adding synergistic fermentation functional bacteria has a significant effect on increasing the total acid and amino acid nitrogen in oatmeal soy sauce and improving the quality of fermented soy sauce.

[0195] Changes of reducing sugars during fermentation Figure 7 shown.

[0196] The results showed that the reducing sugar contents of 6:4, 7:3 and 7:3-WT1 at the end of fermentation were 34.76g / L, 25.39g / L and 18.78g / L respectively, which increased by 5.44 times, 4.03 times and 2.44 times compared with the start of fermentation. Reducing sugar is the main carbon source of microorganisms in the process of soy sauce fermentation, which can be used to convert into organic acids, amino acids, alcohols and so on. Therefore, its content can reflect the fermentation degree of soy sauce. The results showed that the addition of oats and the accession of synergistic fermentation functional strains can promote the fermentation degree of oat soy sauce.

[0197] Organic acids were determined by high performance liquid chromatography. 5 mL of the mash supernatant was diluted 10 times with ultrapure water and filtered through a 0.22 μm filter membrane before testing.

[0198] Table 10: Comparison of organic acid content in each group

[0199]

[0200] The results showed that the addition of oat flour can increase the organic acid content in soy sauce. The total organic acid content of 7:3 and 7:3-WT1 was 21.97 g / L and 22.73 g / L, respectively, which was 7.3% and 11% higher than that of the control group. The succinic acid content of 7:3-WT1 was 5.87 g / L, which was 18.2% higher than that of the control group, and the tartaric acid content was 0.265 g / L, which was 55.9% higher than that of the control group.

[0201] Free amino acids were determined by high performance liquid chromatography using o-xylene (OPA) for in-column derivatization. The mash supernatant (obtained by centrifugation of mash at 12000 r / min for 30 min) was diluted 20 times with 5% trichloroacetic acid and treated for 1 h, and 1 mL of sample was taken for testing after filtering through a 0.22 μm water filter membrane.

[0202] Table 11: Comparison of amino acid content in each group

[0203]

[0204] The total amount of amino acids in the soy sauce fermented by 7:3 and 7:3-WT1 was 42.74g / L and 43.95g / L, which was 8.5% and 11.5% higher than that of the control group.

[0205] Aspartic acid and glutamic acid are the main umami substances in soy sauce. The total amount of umami amino acids in the 7:3-WT1 fermentation group was 12.75g / L, which was 16.4% higher than that in the control group, the most significant increase; the sweet amino acids increased by 9.6%.

[0206] The above results show that the inoculation of the synergistic fermentation strain WT1 at a ratio of soybean to oatmeal = 7:3 can significantly increase the content of umami amino acids and sweet amino acids in soy sauce and increase the content of flavor substances in soy sauce.

[0207] 4) Effects of adding functional strains and changing the ratio on the coloring effect of soy sauce

[0208] Table 12: Effect of WT1 co-fermentation on the color of oatmeal soy sauce

[0209]

[0210] The results showed that when soybean: oatmeal powder = 7:3, the inoculation of synergistic fermentation strain WT1 can significantly deepen the color of soy sauce, the color rate is increased by 11.7% compared with the control group, and the red index and yellow index are increased by 0.96 and 1.92 respectively compared with the control group. The results showed that when soybean: oatmeal powder = 7:3, the inoculation of synergistic fermentation strain WT1 can make the color of oatmeal soy sauce more ruddy, that is, the coloring effect of oatmeal soy sauce is significantly improved.

[0211] In the index of color rate, the 7:3 group increased by 1821 compared with the CK group, the CK-WT1 group increased by 1100 compared with the CK group, and the 7:3-WT group increased by 5027 compared with the CK group. It can be seen that the color rate of the 7:3-WT group increased by 1821 compared with the CK group, which was greater than the sum of the color rates of the 7:3 group and the CK-WT1 group (5027>1821+1100). Therefore, the addition of bacterial agent (WT-1) and the change of raw material composition (the mass ratio of flour to oatmeal flour is 7:3) have a synergistic effect.

[0212] In the yellow index, the 7:3 group increased by 0.62 relative to the CK group, the CK-WT1 group increased by 0.32 relative to the CK group, and the 7:3-WT group increased by 1.92 relative to the CK group. It can be seen that the yellow index of the 7:3-WT group increased relative to the CK group is greater than the sum of the yellow index increases of the 7:3 group and the CK-WT1 group relative to the CK group (1.92>0.62+0.32). Therefore, the addition of bacterial agent (WT-1) and the change of raw material composition (the mass ratio of flour to oatmeal flour is 7:3) have a synergistic effect.

[0213] 5) Effects of adding functional strains and changing the ratio on the antioxidant activity of soy sauce

[0214] Table 13: Effect of WT1 co-fermentation on the antioxidant activity of oatmeal soy sauce

[0215]

[0216] The results showed that when soybean: oatmeal powder = 7:3, the DPPH clearance rate and reducing power of the synergistic fermentation strain WT1 were significantly enhanced, and the DPPH clearance rate and reducing power were 92.93% and 2.47mM Trolox / mL, which were 9% and 32.1% higher than those of the control group, respectively. The DPPH clearance rate and reducing power of the 6:4 and 7:3 groups increased by 1.92% and 16%, 4.16% and 27.3% respectively compared with the control group. This shows that the addition of oatmeal powder and the synergistic effect of the functional strains have improved the antioxidant properties of the fermented soy sauce, and further released the functional substances of the added oatmeal powder.

[0217] In the DPPH clearance index, the 7:3 group increased by 4.16% compared with the CK group, the CK-WT1 group increased by 1.86% compared with the CK group, and the 7:3-WT group increased by 7.86% compared with the CK group. It can be seen that the improved DPPH clearance rate of the 7:3-WT group compared with the CK group is greater than the sum of the improved DPPH clearance rates of the 7:3 group and the CK-WT1 group compared with the CK group (7.86%>4.16%+1.86%). Therefore, the addition of bacterial agents (WT-1) and the change of raw material composition (the mass ratio of flour to oatmeal powder is 7:3) have a synergistic effect.

[0218] In the TEAC index, the 7:3 group increased by 0.65 compared with the CK group, the CK-WT1 group increased by 0.08 compared with the CK group, and the 7:3-WT group increased by 0.81 compared with the CK group. It can be seen that the increase in TEAC of the 7:3-WT group relative to the CK group is greater than the sum of the increases in TEAC of the 7:3 group and the CK-WT1 group relative to the CK group (0.81>0.65+0.08). Therefore, the addition of bacterial agent (WT-1) and the change of raw material composition (the mass ratio of flour to oatmeal flour is 7:3) have a synergistic effect.

[0219] Although the present invention has been disclosed as above in the form of a preferred embodiment, it is not intended to limit the present invention. Anyone familiar with this technology can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be based on the definition of the claims.

Claims

1. A method for preparing oat-brewed soy sauce, characterized in that: The method comprises: using soybean, flour and oatmeal powder as raw materials, mixing the raw materials and Aspergillus oryzae to prepare koji, and preparing finished koji; mixing the finished koji with salt water, inoculating Pediococcus acidilactici WT1, and performing high-salt dilute fermentation to prepare the koji; the final concentration of the salt water in the fermentation system is 16-20 g / 100 ml, and the flour and oatmeal powder are added in an amount of 2-3:8-7 by mass ratio.

2. The preparation method according to claim 1, characterized in that: The amount of Pediococcus acidilactici WT1 added is at least: 1×10 7 CFU / g; Preferably, the high-salt dilute fermentation conditions are as follows: the brine and the koji material are mixed evenly at a mass ratio of 1.8 to 2:1, so that the final concentration of sodium chloride in the system is 16 to 20 g / 100 mL, and at least 1×10 7 CFU / g of lactic acid bacteria Pediococcus WT-1; after sealing, place in a constant temperature incubator at 28-32°C for fermentation for 40-60 days; Preferably, the conditions for preparing the koji are: environmental humidity 90% to 95%, temperature 28° C. to 30° C.; the koji turning time is 16h to 24h, and the koji making operation is terminated when the surface of the koji material is covered with yellow-green spores; Preferably, the raw material is obtained by mixing flour and oatmeal powder in a mass ratio of 2-3:8-7, and then mixing with soybeans in a ratio of 1-4:1-6; Preferably, the Aspergillus oryzae includes but is not limited to Aspergillus oryzae AS3.042 koji, which is added at 1-1.6‰ of the total weight of the raw materials; Preferably, the flour and oatmeal powder are added in a ratio of 7:

3.

3. A soy sauce brewed from oats, characterized in that: The oat-brewed soy sauce is prepared according to the following method: Soybean, flour and oatmeal powder are used as raw materials, and the raw materials and Aspergillus oryzae are mixed to make koji to obtain finished koji; the finished koji is evenly mixed with salt water, and then inoculated with Pediococcus acidilactici WT1 for high-salt dilute fermentation to obtain the finished koji; the final concentration of the salt water in the fermentation system is 16-20g / 100ml, and the flour and oatmeal powder are added in an amount of 2-3:8-7 by mass ratio.

4. The oat-brewed soy sauce according to claim 3, characterized in that: The amount of Pediococcus acidilactici WT1 added is at least: 1×10 7 CFU / g; Preferably, the high-salt dilute fermentation conditions are as follows: the brine and the koji material are mixed evenly at a mass ratio of 1.8 to 2:1, so that the final concentration of sodium chloride in the system is 16 to 20 g / 100 mL, and at least 1×10 7 CFU / g of lactic acid bacteria Pediococcus WT-1; after sealing, place in a constant temperature incubator at 28-32°C for fermentation for 40-60 days; Preferably, the conditions for preparing the koji are: environmental humidity 90% to 95%, temperature 28° C. to 30° C.; the koji turning time is 16h to 24h, and the koji making operation is terminated when the surface of the koji material is covered with yellow-green spores; Preferably, the raw material is obtained by mixing flour and oatmeal powder in a mass ratio of 2-3:8-7, and then mixing with soybeans in a ratio of 1-4:1-6; Preferably, the Aspergillus oryzae includes but is not limited to Aspergillus oryzae AS3.042 koji, which is added at 1-1.6‰ of the total weight of the raw materials; Preferably, the flour and oatmeal powder are added in a ratio of 7:

3.

5. A method for improving the viscosity, antioxidant property, color and flavor of oatmeal soy sauce, characterized in that: The method comprises the following steps: preparing koji using oats as raw material, adding Pediococcus acidilactici WT1 to the prepared koji, and then performing high-salt dilute fermentation; specifically comprising: Soybean, flour and oatmeal powder are used as raw materials, and the raw materials and Aspergillus oryzae are mixed to make koji to obtain finished koji; the finished koji is mixed with salt water, and then inoculated with Pediococcus acidilactici WT1 to perform high-salt dilute fermentation; the final concentration of salt water in the fermentation system is 16-20g / 100ml, and the flour and oatmeal powder are added in an amount of 2-3:8-7 by mass ratio.

6. The method according to claim 5, characterized in that The amount of Pediococcus acidilactici WT1 added is at least: 1×10 7 CFU / g; Preferably, the high-salt dilute fermentation conditions are as follows: the brine and the koji material are mixed evenly at a mass ratio of 1.8 to 2:1, so that the final concentration of sodium chloride in the system is 16 to 20 g / 100 mL, and at least 1×10 7 CFU / g of lactic acid bacteria Pediococcus WT-1; after sealing, place in a constant temperature incubator at 28-32°C for fermentation for 40-60 days; Preferably, the conditions for preparing the koji are: environmental humidity 90% to 95%, temperature 28° C. to 30° C.; the koji turning time is 16h to 24h, and the koji making operation is terminated when the surface of the koji material is covered with yellow-green spores; Preferably, the raw material is obtained by mixing flour and oatmeal powder in a mass ratio of 2-3:8-7, and then mixing with soybeans in a ratio of 1-4:1-6; Preferably, the Aspergillus oryzae includes but is not limited to Aspergillus oryzae AS3.042 koji, which is added in an amount of 1 to 1.6‰ of the total weight of the raw materials.

7. The method according to claim 6, characterized in that When the flour and oatmeal powder are added in a ratio of 7:3, the amount of lactic acid bacteria WT1 added is: 1×10 7 CFU / g.

8. Application of Pediococcus acidilactici WT1 and oat / flour mixture fermentation to increase the content of total flavonoids, total phenols and β-glucan in soy sauce prepared by fermentation with oats as raw materials.

9. The use according to claim 8, characterized in that: Oats are used as raw materials to prepare koji, and lactic acid Pediococcus WT1 is added to the prepared koji to carry out high-salt dilute fermentation; specifically, the process comprises: using soybean, flour and oatmeal powder as raw materials, mixing the raw materials and Aspergillus oryzae to prepare koji; mixing the obtained koji with salt water, inoculating lactic acid Pediococcus WT1 and carrying out high-salt dilute fermentation; the final concentration of salt water in the fermentation system is 16-20g / 100ml, and the flour and oatmeal powder are added in an amount of 2-3:8-7 by mass ratio.

10. The use according to claim 8 or 9, characterized in that: The amount of Pediococcus acidilactici WT1 added is at least: 1×10 7 CFU / g; Preferably, the high-salt dilute fermentation conditions are as follows: the brine and the koji material are mixed evenly at a mass ratio of 1.8 to 2:1, so that the final concentration of sodium chloride in the system is 16 to 20 g / 100 mL, and at least 1×10 7 CFU / g of lactic acid bacteria Pediococcus WT-1; after sealing, place in a constant temperature incubator at 28-32°C for fermentation for 40-60 days; Preferably, the conditions for preparing the koji are: environmental humidity 90% to 95%, temperature 28° C. to 30° C.; the koji turning time is 16h to 24h, and the koji making operation is terminated when the surface of the koji material is covered with yellow-green spores; Preferably, the raw material is obtained by mixing flour and oatmeal powder in a mass ratio of 2-3:8-7, and then mixing with soybeans in a ratio of 1-4:1-6; Preferably, the Aspergillus oryzae includes but is not limited to Aspergillus oryzae AS3.042 koji, which is added at 1-1.6‰ of the total weight of the raw materials; Preferably, the flour and oatmeal powder are added in a ratio of 7:3.

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