Soy sauce and production method thereof

Abstract

The invention relates to the field of soy sauce brewing, and discloses soy sauce and a production method thereof. The method comprises the following steps: performing first mixing on finished koji and saline water, and fermenting; wherein the fermentation mode comprises the following steps: inoculating a leavening agent A, a leavening agent B and a leavening agent C into the first mixed material; wherein the leavening agent A comprises tetrastreptococcus halophilus; the leavening agent B comprises kluyveromyces cerevisiae, saccharomyces rouxii and saccharomyces cerevisiae; the leavening agent C comprises lactic acid bacteria. By adopting the method, the soy sauce with relatively low aflatoxin content can be produced, and the produced soy sauce is relatively high in flavor substance content and relatively good in sensory quality.

Description

Technical Field

[0001] The invention relates to the field of soy sauce brewing, and in particular to soy sauce and a production method thereof. Background Art

[0002] Aflatoxins are a class of secondary metabolites produced by Aspergillus flavus and Aspergillus parasiticus. Among the more than 20 types of aflatoxins that have been discovered, aflatoxin B1 (AFB1) has the strongest teratogenicity, mutagenicity and carcinogenicity. In 1993, the World Health Organization classified AFB1 as a Class I carcinogen.

[0003] There is also the possibility of aflatoxin contamination during the production process of soy sauce, which makes it difficult to control the aflatoxin content in soy sauce below the limit standard, resulting in safety risks in soy sauce production.

[0004] In addition, the hot pressing method is currently mostly used to produce peanut oil, so the peanut meal obtained is mostly hot-pressed peanut meal. The temperature of hot-pressed peanut meal is often very high during the processing process, and the thermal denaturation of peanut protein is serious, and its nutritional value and functional characteristics are affected to varying degrees. Moreover, peanut meal is mostly only used as fertilizer or animal feed, resulting in a huge waste of peanut protein resources. In addition, peanuts are easily contaminated by molds such as Aspergillus flavus during growth, harvesting, storage and transportation, and carry aflatoxin. Soy sauce is a traditional condiment in my country. If peanut meal is used to brew soy sauce, the comprehensive utilization and reuse of various protein and starch raw material by-products can be achieved. Therefore, it is currently necessary to develop a soy sauce production process that can reduce the aflatoxin content in the obtained soy sauce, especially to produce soy sauce with peanut meal as a raw material to fully utilize the peanut meal as a resource. Summary of the invention

[0005] The purpose of the present invention is to overcome the above-mentioned problems existing in the prior art and to provide a soy sauce and a production method thereof. By adopting the method, soy sauce with a low aflatoxin content can be produced, and the produced soy sauce has a high content of flavor substances and good sensory quality.

[0006] In order to achieve the above object, the first aspect of the present invention provides a method for producing soy sauce, the method comprising: first mixing and fermenting koji and brine;

[0007] The fermentation method includes: inoculating fermentation agent A, fermentation agent B and fermentation agent C into the first mixed material;

[0008] Wherein, fermentation agent A includes halophilic tetrastreptococcus;

[0009] Starter B includes Kluyveromyces, Saccharomyces rouxii, and Saccharomyces cerevisiae;

[0010] The starter C includes lactic acid bacteria.

[0011] The second aspect of the present invention provides soy sauce prepared by the method as described above.

[0012] The aflatoxin content of the soy sauce produced by the above technical solution is far lower than the national standard (GB2761-2017 "National Food Safety Standard Limit of Mycotoxins in Food", 5μg / k g ), and the content of flavor substances such as acids, esters, alcohols, aldehydes, ketones, etc. in soy sauce is also high, so the soy sauce is more mellow and has better sensory quality. In the case of preferably using peanut meal as raw material, the peanut meal can also be fully utilized to achieve full utilization of resources. DETAILED DESCRIPTION

[0013] The endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0014] In a first aspect, the present invention provides a method for producing soy sauce, comprising first mixing and fermenting koji and brine;

[0015] The fermentation method includes: inoculating fermentation agent A, fermentation agent B and fermentation agent C into the first mixed material;

[0016] Wherein, fermentation agent A includes halophilic tetrastreptococcus;

[0017] Starter B includes Kluyveromyces, Saccharomyces rouxii, and Saccharomyces cerevisiae;

[0018] The starter C includes lactic acid bacteria.

[0019] The inventors of the present invention have found in their research that if the composite strains in the above method are used for fermentation, the aflatoxin content in the prepared soy sauce is far lower than the national standard, and the content of flavor substances such as acids, esters, alcohols, aldehydes, ketones in the soy sauce is also high, the soy sauce is mellower and has better sensory quality.

[0020] According to the present invention, preferably, the method further comprises the step of preparing finished koji, and the method of preparing finished koji comprises: steaming the raw material, and then mixing the steamed raw material with the seed koji for a second time, and culturing the second mixed material to obtain finished koji. The purpose of preparing finished koji is to allow the seed koji to fully grow and multiply on the raw material, and obtain various enzymes required in the soy sauce brewing process. It can be understood that finished koji refers to the mixture of bacteria and raw materials finally obtained after the seed koji grows and multiplies on the raw material.

[0021] According to the present invention, preferably, the raw materials include protein raw materials and starch raw materials. In the present invention, there is no particular limitation on the specific selection of protein raw materials and starch raw materials.

[0022] According to the present invention, preferably, on a dry basis, the mass ratio of the protein raw material to the starch raw material is 1:(0.6-1.1).

[0023] According to the present invention, preferably, the protein raw material is selected from at least one of peanut raw material, soybean raw material and rapeseed meal, more preferably selected from peanut meal and / or soybean meal.

[0024] According to the present invention, preferably, the starchy raw material is oat flakes. The oat flakes may be raw oat flakes, that is, a product obtained by pressing raw wheat into flakes.

[0025] According to a particularly preferred embodiment of the present invention, the raw materials include peanut meal, soybean meal and oatmeal. The inventors of the present invention found in further research that when peanut meal is used as part of the raw material, on the one hand, while ensuring that the aflatoxin content in the obtained soy sauce is low, the peanut meal can be fully utilized as a resource, and the by-products produced when peanuts are pressed for oil are fully utilized, thereby improving the utilization rate of peanuts and the added value of peanut meal, and effectively avoiding waste of resources; on the other hand, the soy sauce obtained by fermenting the raw materials with this specific ingredient also has better flavor quality, and also enriches the variety of soy sauces on the market.

[0026] According to the present invention, preferably, in the raw materials, the mass ratio of peanut meal to soybean meal on a dry basis is 1:(0.5-1.6), more preferably 1:(0.8-1.2). The inventors of the present invention also found that when peanut meal and soybean meal are used at the same time and the above ratio is met, the koji making effect is better, the protease activity of the koji is higher, and more spores are produced.

[0027] According to the present invention, preferably, the cooking temperature is 115-126° C., the time is 0.3-0.5 h, and the pressure is 0.08-0.15 MPa.

[0028] According to the present invention, preferably, the seed koji is Aspergillus oryzae seed koji. The present invention has no particular restrictions on the specific type and source of the Aspergillus oryzae seed koji, which can be an Aspergillus oryzae seed koji prepared by itself according to the prior art, or a commercially available finished seed koji (for example, Aspergillus oryzae Shanghai Brewing 3.042 seed koji purchased from Shandong Hezhong Kangyuan Biotechnology Co., Ltd.).

[0029] According to the present invention, preferably, the inoculation amount of the seed koji is such that the initial content of Aspergillus oryzae spores in the second mixed material is 1×10 8 Up to 3×10 8cfu / g. After inoculating the seed, the materials can be mixed evenly.

[0030] According to the present invention, preferably, the step of preparing the koji further includes: before cooking, mixing peanut meal, soybean meal and water for the third time, and then mixing the third mixed material and oatmeal for the fourth time, the material obtained by the fourth mixing is used for cooking, wherein the mass of water used for the third mixing is 0.8-1.2 times the total mass of peanut meal, soybean meal and oatmeal (for example, it can be 0.8 times, 0.9 times, 1 times, 1.1 times, 1.2 times and the range formed by any two of the above values ​​and the value within the range). Before cooking, the third mixing is first performed, and the protein raw material can contain an appropriate amount of water to expand the tissue so that the protein can quickly achieve a moderate deformation during cooking.

[0031] The third mixing can be performed at room temperature (such as 22-27° C.), and the mixing time can be 30-60 min (for example, 30 min, 35 min, 40 min, 45 min, 50 min, 55 min, 60 min, and any range formed by any two of the above values ​​and values ​​within the range). The time refers to the time taken for the peanut meal, soybean meal and water to be fully infiltrated by the water after the peanut meal, soybean meal and water are mixed. For example, after the peanut meal, soybean meal and water are mixed, they can be left to stand for 30 min to allow the water to fully infiltrate the peanut meal and soybean meal; and then fully mixed with the oatmeal.

[0032] According to the present invention, preferably, the step of preparing the koji further comprises: cooling the steamed raw material before mixing it with the seed koji, preferably cooling it to 35-42°C (for example, it can be 35°C, 38°C, 40°C, 42°C, and a range formed by any two of the above values ​​and a value within the range). This is more conducive to the germination of Aspergillus oryzae spores and can also prevent the rapid proliferation of miscellaneous bacteria.

[0033] According to the present invention, preferably, the culturing method includes: subjecting the second mixed material to a first culturing, then turning the material over, and then subjecting the material to a second culturing.

[0034] According to the present invention, preferably, the first culturing method comprises: culturing at 30-32° C. for 16-20 h to obtain a first culture product.

[0035] According to the present invention, preferably, the method of turning the koji comprises: turning the first culture product for the first time, turning the first turned koji product for the second time after 6-8 hours, and obtaining a second turned koji product. It can be understood that turning the koji refers to loosening the koji material, reducing ventilation resistance, and making the temperature of the koji material uniform, so as to facilitate the normal growth and reproduction of Aspergillus oryzae. After the first turning, it is laid flat. The temperature during turning can be consistent with the temperature of the first culture.

[0036] According to the present invention, preferably, the second culturing method comprises: culturing the second koji product at 28-30°C for 16-18h.

[0037] In the preparation of finished koji, the cultivation condition of the finished koji is generally judged by observing its state. When the koji appears green, the spores are obviously raised, and there is no peculiar smell, it can be considered that the cultivation effect of the finished koji is good.

[0038] According to the present invention, preferably, the amount of brine used is 2-2.5 L relative to 1 kg of raw material.

[0039] According to the present invention, preferably, the concentration of salt in the brine is 18-25wt% (for example, it can be 18wt%, 19wt%, 20wt%, 21wt%, 22wt%, 23wt%, 24wt%, 25wt% and the range formed by any two of the above values ​​and the value within the range). It can be understood that in soy sauce fermentation, the salt in the brine refers to sodium chloride.

[0040] According to the present invention, preferably, the fermentation further comprises temperature control during the fermentation process, and the temperature control method comprises: firstly performing temperature-raising fermentation, and when the temperature rises to a constant temperature, performing constant temperature fermentation until the fermentation ends. It can be understood that the temperature-raising fermentation refers to fermentation under the condition of gradually rising temperature.

[0041] According to the present invention, preferably, the starting temperature is 13-16°C.

[0042] According to the present invention, preferably, the heating rate of the temperature-raising fermentation is 0.8-1.5°C / day.

[0043] According to the present invention, preferably, the constant temperature is 29-31°C.

[0044] The inventors of the present invention further discovered in their research that, when the above conditions are met, gradually increasing the fermentation temperature from a lower temperature can also inhibit bacterial acid production, slowly reduce the pH of the mash, and facilitate the role of amylase, neutral protease and alkaline protease of Aspergillus oryzae.

[0045] According to the present invention, preferably, the total fermentation time is 170-190 days.

[0046] According to the present invention, preferably, the fermentation method includes: inoculating fermentation agent A into the first mixed material, performing a first-stage fermentation, and obtaining a first-stage fermentation liquid; then inoculating fermentation agent B into the first-stage fermentation liquid, performing a second-stage fermentation, and obtaining a second-stage fermentation liquid; then inoculating fermentation agent C into the second-stage fermentation liquid, and performing a third-stage fermentation. The inventors of the present invention unexpectedly found that if the strains are inoculated in the above-mentioned specific order, the aflatoxin in the obtained soy sauce can be further reduced, and the content of flavor substances in the obtained soy sauce can be further guaranteed, so that the soy sauce is more mellow and has better sensory quality.

[0047] According to the present invention, preferably, on the 10th to 20th day (for example, 10th, 11th, 12th, 13th, 14th, 15th, 16th, 17th, 18th, 19th, 20th) of fermentation, starter A is inoculated into the fermentation broth.

[0048] According to the present invention, preferably, on day 28-35 (for example, day 28, 29, 30, 31, 32, 33, 34, 35) of fermentation, starter culture B is inoculated into the fermentation broth.

[0049] According to the present invention, preferably, on day 90-100 (for example, day 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 100) of fermentation, starter C is inoculated into the fermentation broth.

[0050] The inventors of the present invention have found in their research that inoculating the strains in stages according to the above time periods is beneficial to the growth of various microorganisms, can further ensure the reduction of aflatoxin in the resulting soy sauce, and further ensure the content of flavor substances in the resulting soy sauce.

[0051] According to the present invention, preferably, the fermentation agent A is Tetragenococcus halophilus.

[0052] According to the present invention, preferably, the fermentation agent B is Kluyveromyces, Saccharomyces rouxii and Saccharomyces cerevisiae, and the Kluyveromyces is preferably Kluyveromyces marxianus. The present invention has no particular restrictions on the specific source of the Kluyveromyces marxianus, which can be a related strain isolated and obtained by itself, or can be directly purchased through commercial channels, for example, it can be Kluyveromyces marxianus CICC 31993 purchased from the China Industrial Microbiological Culture Collection Administration Center.

[0053] According to the present invention, preferably, the inoculation amount of Saccharomyces rouxii, Saccharomyces kluyveromyces and Saccharomyces cerevisiae is such that the initial viable bacterial count ratio in the second-stage fermentation system is 1:(1.8-2.2):(1.8-2.2). Under the above conditions, it is possible to further ensure that the strains grow in a coordinated manner and produce rich alcohols without causing too much alcohol to cover up the soy sauce flavor.

[0054] According to the present invention, preferably, the starter C further comprises acetic acid bacteria; preferably, the lactic acid bacteria is Lactobacillus plantarum.

[0055] According to the present invention, preferably, the starter C is acetic acid bacteria and Lactobacillus plantarum, and preferably the inoculation amount of the acetic acid bacteria and Lactobacillus plantarum is such that the initial viable count ratio in the three-stage fermentation system is 1:(0.8-1.2). This can further ensure the normal growth of the strain, further ensure the production of multiple organic acids, and further improve the sour aroma of the soy sauce.

[0056] The specific strains of each bacterial species described above are not particularly limited, as long as they can meet the requirements of the respective bacterial species. For example, Tetragenococcus halophilus can be Tetragenococcus halophilus CICC 10286 purchased from the China Industrial Microbiological Culture Collection Administration Center. Zygosaccharomyces rouxii can be Zygosaccharomyces rouxii CICC 1379 purchased from the China Industrial Microbiological Culture Collection Administration Center. Saccharomyces cerevisiae can be Saccharomyces cerevisiae CICC 32883 purchased from the China Industrial Microbiological Culture Collection Administration Center. Acetobacter pasteurianus can be Acetobacter pasteurianus CICC 20874 purchased from the China Industrial Microbiological Culture Collection Administration Center. Lactobacillus plantarum can be Lactobacillus plantarum CICC 22139 purchased from the China Industrial Microbiological Culture Collection Administration Center.

[0057] According to the present invention, preferably, the inoculation amount of the fermentation agent A is such that its initial content in the first stage fermentation system is 8×10 5 to 1.5×10 6 cfu / g.

[0058] According to the present invention, preferably, the inoculation amount of the starter B is such that its initial total content in the second-stage fermentation system is 1×10 6 Up to 1×10 7 cfu / g.

[0059] According to the present invention, preferably, the inoculation amount of the starter C is such that its initial content in the three-stage fermentation system is 1×10 5 Up to 3×10 5 cfu / g.

[0060] Under the above dosage conditions, the flavor substances in the soy sauce can be guaranteed to be more coordinated.

[0061] After the fermentation is completed, the fermented sauce mash can be filtered, and then the filtered liquid phase can be sterilized at 75-85° C. for 20-60 minutes, and then allowed to stand and filtered to remove the precipitate to obtain the finished soy sauce.

[0062] In a second aspect, the present invention provides soy sauce prepared by the method as described above.

[0063] According to the present invention, preferably, the content of aflatoxin B1 in the soy sauce is ≤5 μg / kg.

[0064] The present invention will be described in detail below through examples.

[0065] In the following examples and comparative examples, Tetragenococcus halophilus, Kluyveromyces marxianus, Saccharomyces rouxii, Saccharomyces cerevisiae, Acetobacter, Lactobacillus plantarum, Candida albicans, Lactobacillus brevis, and Weissella mesenteroides were purchased from the China Industrial Microbiological Culture Collection Administration Center.

[0066] Among them, the strain number of halophilic Tetragenococcus is CICC 10286; the strain number of Kluyveromyces marxianus is CICC 31993; the strain number of Saccharomyces rouxii is CICC 1379; the strain number of Saccharomyces cerevisiae is CICC 32883; the strain number of acetic acid bacteria is CICC 20874; the strain number of Lactobacillus plantarum is CICC 22139; the strain number of Candida albicans is CICC 31170; the strain number of Lactobacillus brevis is CICC 23474; and the strain number of Weissella mesenteroides is CICC24392.

[0067] Aspergillus oryzae seed koji was purchased from Shandong Hezhong Kangyuan Biotechnology Co., Ltd. with the product number of Aspergillus oryzae Shanghai Brew 3.042 seed koji.

[0068] Example 1

[0069] (1) Peanut meal, soybean meal and raw oat flakes are taken, and the mass ratio of peanut meal, soybean meal and raw oat flakes is 1:1:2 on a dry basis. Peanut meal and soybean meal are mixed for the third time, and water is added thereto (the mass of water is 0.9 times the total mass of oat flakes, peanut meal and soybean meal). After soaking for 30 minutes at room temperature, oat flakes are added thereto, and mixed for the fourth time to make the mixture uniform. The above materials are steamed at 121°C and 0.1MPa for 0.4h.

[0070] After the cooked material was cooled to 42°C, Aspergillus oryzae seed was inoculated therein (i.e., a second mixing was performed), and the initial content of Aspergillus oryzae spores in the material after the second mixing was 1×10 8 cfu / g.

[0071] (2) The second mixed material is cultured at 30°C for 20 hours, then turned over for the first time and spread out. After 8 hours, it is turned over again for the second time. Then the temperature is lowered to 28°C and cultured for 18 hours to obtain finished koji.

[0072] (3) The finished koji is added to brine having a salt concentration of 20 wt% (i.e., the first mixing is performed), and the amount of brine is 2.2 L relative to 1 kg of the raw material.

[0073] The first mixed material was fermented at an initial temperature of 15° C., and the temperature was raised to 30° C. at a rate of 1° C. / day; then, the fermentation was carried out at a constant temperature at 30° C. The total fermentation time was 180 days.

[0074] On the 15th day of fermentation, halophilic Tetragenococcus was inoculated into the fermentation system so that its initial content in the fermentation system was 1×10 6 cfu / g;

[0075] On the 30th day of fermentation, Kluyveromyces marxianus, Saccharomyces rouxii and Saccharomyces cerevisiae were inoculated so that the initial content of the three in the fermentation system was 1×10 7 cfu / g, and the inoculation amounts of Saccharomyces rouxii, Kluyveromyces marxianus and Saccharomyces cerevisiae were such that the initial viable count ratio in the fermentation system was 1:2:2.

[0076] On the 90th day of fermentation, acetic acid bacteria and Lactobacillus plantarum were inoculated so that the initial content of the two in the fermentation system was 1×10 5 cfu / g, and the inoculation amounts of acetic acid bacteria and Lactobacillus plantarum were such that the initial viable count ratio in the fermentation system was 1:1.

[0077] (4) After the fermentation is completed, the fermented mash is filtered, and then the filtered liquid phase is sterilized at 80° C. for 30 min, allowed to stand, filtered to remove the precipitate, and then the finished soy sauce is obtained.

[0078] Example 2

[0079] (1) Peanut meal, soybean meal and raw oat flakes are taken, and the mass ratio of peanut meal, soybean meal and raw oat flakes is 1:0.8:1.08 on a dry basis. Peanut meal and soybean meal are mixed for the third time, and water is added thereto (the mass of water is 0.8 times the total mass of oat flakes, peanut meal and soybean meal). After soaking at room temperature for 40 minutes, oat flakes are added thereto, and mixed for the fourth time to make the mixture uniform. The above materials are steamed at 115°C and 0.08MPa for 0.5h.

[0080] After the cooked material was cooled to 38°C, Aspergillus oryzae spores were inoculated therein (i.e., the second mixing was performed), and the initial content of Aspergillus oryzae spores in the material after the second mixing was 2×108 cfu / g.

[0081] (2) The second mixed material is cultured at 31°C for 18 hours, then turned over for the first time and spread out. After 7 hours, it is turned over again for the second time. The temperature is lowered to 29°C and cultured for 17 hours to obtain finished koji.

[0082] (3) The finished koji is added to brine having a salt concentration of 18 wt% (i.e., the first mixing is performed), and 2 L of brine is added relative to 1 kg of the raw material.

[0083] The first mixed material was subjected to temperature-raising fermentation at an initial temperature of 13° C., and the temperature was raised to 29° C. at a rate of 0.8° C. / day; and then a second constant-temperature fermentation was carried out at 29° C. The total fermentation time was 176 days.

[0084] On the 20th day of fermentation, halophilic Tetragenococcus was inoculated into the fermentation system, so that its initial content in the fermentation system was 8×10 5 cfu / g;

[0085] On the 35th day of fermentation, Kluyveromyces marxianus, Saccharomyces rouxii and Saccharomyces cerevisiae were inoculated so that the initial content of the three in the fermentation system was 1×10 6 cfu / g, and the inoculation amounts of Saccharomyces rouxii, Kluyveromyces marxianus and Saccharomyces cerevisiae made the initial viable cell count ratio in the fermentation system be 1:1.8:1.8.

[0086] On the 95th day of fermentation, acetic acid bacteria and Lactobacillus plantarum were inoculated into the fermentation system, so that the initial content of the two in the fermentation system was 2×10 5 cfu / g, and the inoculation amounts of acetic acid bacteria and Lactobacillus plantarum made the initial viable bacteria ratio in the fermentation system be 1:0.8.

[0087] (4) After the fermentation is completed, the fermented mash is filtered, and then the filtered liquid phase is sterilized at 75° C. for 60 min, allowed to stand, filtered to remove the precipitate, and then the finished soy sauce is obtained.

[0088] Example 3

[0089] (1) Peanut meal, soybean meal and raw oat flakes are taken, and the mass ratio of peanut meal, soybean meal and raw oat flakes is 1:1.2:2.42 on a dry basis. Peanut meal and soybean meal are mixed for the third time, and water is added thereto (the mass of water is 1.2 times the total mass of oat flakes, peanut meal and soybean meal). After soaking for 60 minutes at room temperature, oat flakes are added thereto, and mixed for the fourth time to make the mixture uniform. The above materials are steamed at 126°C and 0.15MPa for 0.3h.

[0090] After the cooked material was cooled to 35°C, Aspergillus oryzae spores were inoculated therein (i.e., the second mixing was performed), and the initial content of Aspergillus oryzae spores in the material after the second mixing was 3×10 8 cfu / g.

[0091] (2) The second mixed material is cultured at 32°C for 16 hours, then turned over for the first time and spread out. After 6 hours, it is turned over again for the second time. The temperature is lowered to 30°C and cultured for 16 hours to obtain finished koji.

[0092] (3) The finished koji is added to brine having a salt concentration of 25 wt% (i.e., the first mixing is performed), and the amount of brine is 2.5 L relative to 1 kg of the raw material.

[0093] The first mixed material was fermented at an initial temperature of 16° C., and then the temperature was raised to 31° C. at a rate of 1.5° C. / day; and then fermented at a constant temperature at 31° C. The total fermentation time was 185 days.

[0094] On the 12th day of fermentation, halophilic Tetragenococcus was inoculated into the fermentation system so that its initial content in the fermentation system was 1.5×10 6 cfu / g;

[0095] On the 28th day of fermentation, Kluyveromyces marxianus, Saccharomyces rouxii and Saccharomyces cerevisiae were inoculated to make the initial content of the three in the fermentation system 5×10 6 cfu / g, and the inoculation amounts of Saccharomyces rouxii, Kluyveromyces marxianus and Saccharomyces cerevisiae made the initial viable cell count ratio in the fermentation system be 1:2.2:2.2.

[0096] On the 100th day of fermentation, acetic acid bacteria and Lactobacillus plantarum were inoculated into the fermentation system, so that the initial content of the two in the fermentation system was 3×10 5 cfu / g, and the inoculation amounts of acetic acid bacteria and Lactobacillus plantarum made the initial viable cell count ratio in the fermentation system be 1:1.2.

[0097] (4) After the fermentation is completed, the fermented soy sauce mash is filtered, and then the filtered liquid phase is sterilized at 85° C. for 40 minutes, allowed to stand, filtered to remove the precipitate, and then the finished soy sauce is obtained.

[0098] Example 4

[0099] The steps (1)-(2) in Example 1 are followed, except that peanut meal is not used, but the mass of soybean meal is adjusted to be consistent with the total mass of the peanut meal and soybean meal in Example 1.

[0100] Example 5

[0101] The steps (1)-(2) in Example 1 are followed to obtain finished koji, except that the total mass of peanut meal and soybean meal is the same as that in Example 1, but the mass ratio of peanut meal to soybean meal is 1:2.

[0102] Example 6

[0103] The method of Example 1 was followed, except that the inoculation amounts of Saccharomyces rouxii, Saccharomyces kluyveromyces and Saccharomyces cerevisiae were such that the initial viable bacterial count ratio in the fermentation system was 1:3:4.

[0104] Example 7

[0105] The method of Example 1 was followed, except that the total inoculation amount of Kluyveromyces, Saccharomyces rouxii and Saccharomyces cerevisiae was such that the initial total content of the Kluyveromyces, Saccharomyces rouxii and Saccharomyces cerevisiae in the fermentation system was 1×10 8 cfu / g.

[0106] Example 8

[0107] The method of Example 1 was followed, except that the inoculation amounts of acetic acid bacteria and Lactobacillus plantarum were such that the initial viable bacterial count ratio in the fermentation system was 1:2.

[0108] Example 9

[0109] The method of Example 1 was followed, except that the inoculation amount of acetic acid bacteria and Lactobacillus plantarum was such that the initial total content of the acetic acid bacteria and Lactobacillus plantarum in the fermentation system was 5×10 5 cfu / g.

[0110] Example 10

[0111] The method of Example 1 was followed, except that acetic acid bacteria and Lactobacillus plantarum were replaced by Lactobacillus brevis and Weissella mesenteroides (both of which belong to lactic acid bacteria).

[0112] Embodiment 11

[0113] The steps (1)-(2) in Example 1 were followed, except that the peanut meal was replaced with rapeseed meal.

[0114] Comparative Example 1

[0115] The method of Example 1 was followed, except that on the 30th day of fermentation, Saccharomyces rouxii and Kluyveromyces marxianus were inoculated into the fermentation system, and the initial content of the two in the fermentation system was 1×10 7 cfu / g, the inoculation amount of Saccharomyces rouxii and Kluyveromyces marxianus was such that the ratio of their viable counts was 1:1.

[0116] Comparative Example 2

[0117] The method of Example 1 was followed, except that on the 30th day of fermentation, Saccharomyces rouxii was inoculated into the fermentation system. The initial content of Saccharomyces rouxii in the fermentation system was 1×10 7 cfu / g.

[0118] Comparative Example 3

[0119] The method of Example 1 was followed, except that Kluyveromyces marxianus was replaced by Candida sp.

[0120] Comparative Example 4

[0121] The method of Example 1 was followed, except that Tetragenococcus halophilus, Kluyveromyces marxianus, Saccharomyces rouxii and Saccharomyces cerevisiae were not inoculated; on the 90th day of fermentation, acetic acid bacteria and Lactobacillus plantarum were inoculated in the manner of Example 1.

[0122] Comparative Example 5

[0123] The method of Example 1 was followed, except that during the fermentation process, Kluyveromyces marxianus, Saccharomyces rouxii, Saccharomyces cerevisiae, acetic acid bacteria and Lactobacillus plantarum were not inoculated.

[0124] Comparative Example 6

[0125] The method of Example 1 was followed, except that acetic acid bacteria and Lactobacillus plantarum were not inoculated during the fermentation process.

[0126] Comparative Example 7

[0127] The method of Example 1 was followed, except that during the fermentation process, Tetragenococcus halophilus, Kluyveromyces marxianus, Saccharomyces rouxii, Saccharomyces cerevisiae, Acetobacter and Lactobacillus plantarum were not inoculated.

[0128] Test Example 1

[0129] The soy sauce products prepared in the above examples and comparative examples were used to measure the aflatoxin content using a total aflatoxin detection kit (Nanjing Herb Source Biotechnology Co., Ltd.). The results are shown in Table 1.

[0130] Table 1

[0131]

[0132]

[0133] It can be seen from the results in Table 1 that the aflatoxin content in the soy sauce obtained by using the embodiments of the technical solution provided by the present invention is significantly lower than the national standard of 5 μg / kg, especially in Examples 1-3, the aflatoxin content is significantly lower.

[0134] Test Example 2

[0135] The finished koji samples prepared in Examples 1-5 and 11 were taken, the state of the finished koji was observed, and the protease activity of the finished koji (expressed as the content of amino acid nitrogen in 100 g of the finished koji) was determined according to the "SB / T10317-1999 Formaldehyde Method". The results are shown in Table 2.

[0136] Table 2

[0137]

[0138] The inventors of the present invention have found in their research that, compared with the case of using only peanut meal or soybean meal, when peanut meal and soybean meal are used together, the amino acid nitrogen is higher, the color state of Daqu is better, the koji making effect is better, and it is more conducive to subsequent fermentation. In particular, when the mass ratio of peanut meal to soybean meal is 1: (0.8-1.2), the effect is best. Compared with the case of mixing rapeseed meal with soybean meal, the Daqu obtained when peanut meal and soybean meal are mixed to make koji has significantly better protease activity.

[0139] Test Example 3

[0140] The pH of the soy sauce products prepared in the above embodiments and comparative examples was measured, and the total acid content thereof was measured using "GB 18186-2000 Brewing Soy Sauce". The results are shown in Table 3.

[0141] Table 3

[0142] sample pH Example 1 3.98 Example 2 4.05 Example 3 4.01 Example 6 4.23 Example 7 4.17 Example 8 4.11 Example 9 4.32 Example 10 4.28 Embodiment 11 4.33 Comparative Example 1 4.70 Comparative Example 2 4.53 Comparative Example 3 4.48 Comparative Example 4 4.75 Comparative Example 5 4.65 Comparative Example 6 4.59 Comparative Example 7 4.91

[0143] The contents of several organic acids (oxalic acid, succinic acid, tartaric acid, citric acid, malic acid, acetic acid, propionic acid, lactic acid and formic acid) in the soy sauces obtained in Example 1 and Comparative Example 7 were determined by high performance liquid chromatography, and the results are shown in Table 4.

[0144] Table 4

[0145] Organic acid (g / 100mL) Example 1 Comparative Example 7 oxalic acid 0.215 0.096 Succinic acid 1.46 0.719 tartaric acid 0.015 0.009 Citric Acid 0.018 0.009 Malic Acid 0.034 0.005 Propionic acid 0.138 0.132 lactic acid 1.38 1.121 Formic acid 0.015 0.012

[0146] Succinic acid and malic acid are important participants in the tricarboxylic acid cycle. It can be seen that the method of Example 1 can significantly increase the organic acid content of soy sauce, especially oxalic acid, succinic acid, malic acid and acetic acid.

[0147] Test Example 4

[0148] The soy sauce products prepared in the above embodiments and comparative examples were subjected to sensory evaluation. The specific method was as follows: the participants consisted of 14 members (7 males and 7 females, aged 22 to 45 years old) with sensory evaluation experience (at least one year of training), and scored the aroma, taste, color and body of each soy sauce product. The results are shown in Table 5, and the detailed sensory evaluation criteria are shown in Table 6.

[0149] Table 5

[0150]

[0151]

[0152] Table 6

[0153]

[0154] It can be seen that the soy sauce prepared by the method provided by the present invention has a high score, especially the soy sauce prepared by Examples 1-3 has a higher comprehensive score, rich soy sauce flavor, no peculiar smell, strong and mellow umami taste, and a reddish brown and shiny clear liquid. It can also be seen that the soy sauce product provided by the scheme of the present invention has better quality and can utilize peanut meal to achieve full utilization of resources.

[0155] By solid phase microextraction (SPME) combined with gas chromatography-mass spectrometry (GC-MS), other flavor substances in the soy sauce products prepared in Examples 1-3 and Comparative Example 7 were determined, including esters, alcohols, aldehydes, ketones, pyrazines, alkanes and phenols. The results are shown in Table 7.

[0156] Table 7

[0157]

[0158]

[0159] In the soy sauce of Examples 1-3, the contents of esters, acids, pyrazines and phenols are much higher than those in Comparative Example 7 (the soy sauce of Comparative Example 7 is also the traditional high-salt dilute soy sauce). Esters are important flavor substances in soy sauce, which usually give soy sauce fruity and floral aromas. The soy sauce samples of Examples 1-3 have more types of ester substances, making the soy sauce aroma richer and more balanced. The volatile acid in the soy sauce is greatly increased by acidic fermentation, which gives the soy sauce a sour aroma and buffers the saltiness brought by high concentrations of salt. Saccharomyces cerevisiae has good ethanol fermentation performance. In addition to producing ethanol as the main metabolite, it also produces flavor metabolites such as higher alcohols, esters, aldehydes, phenols, acids, and diones. Each higher alcohol substance has its own unique aroma and taste characteristics. Pyrazine substances are mainly transformed from branched-chain amino acids through enzyme biosynthesis produced by microorganisms. They can increase the sauce flavor of soy sauce and are important aroma substances in soy sauce. Phenolic substances, such as 2-ethyl-3,6-dimethylpyrazine and 4-ethylguaiacol, respectively bring soy sauce aroma and smoky aroma to soy sauce. It can be seen that the method provided by the present invention has a significant positive effect on the content of the main aroma substances of soy sauce and the types of aroma substances in soy sauce.

[0160] The preferred embodiments of the present invention are described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention.

Claims

1. A method for producing soy sauce, characterized in that: The method comprises: first mixing and fermenting the koji and salt water; The fermentation method includes: inoculating fermentation agent A, fermentation agent B and fermentation agent C into the first mixed material; Wherein, fermentation agent A includes halophilic tetrastreptococcus; Starter B includes Kluyveromyces, Saccharomyces rouxii, and Saccharomyces cerevisiae; The starter C includes lactic acid bacteria.

2. The method according to claim 1, wherein: The method further comprises the step of preparing finished koji, wherein the method of preparing finished koji comprises: steaming the raw material, then second mixing the steamed raw material with the seed koji, and culturing the second mixed material to obtain finished koji; Preferably, the raw materials include protein raw materials and starch raw materials; More preferably, the mass ratio of the protein raw material to the starch raw material is 1:(0.6-1.1) on a dry basis; Preferably, the protein raw material is selected from at least one of peanut raw material, soybean raw material and rapeseed meal, preferably selected from peanut meal and / or soybean meal; Preferably, the starchy raw material is oatmeal; Preferably, the raw materials include peanut meal, soybean meal and oatmeal; More preferably, in the raw materials, the mass ratio of peanut meal to soybean meal on a dry basis is 1:(0.5-1.6), more preferably 1:(0.8-1.2); Preferably, the cooking temperature is 115-126°C, the time is 0.3-0.5h, and the pressure is 0.08-0.15MPa; Preferably, the seed koji is Aspergillus oryzae seed koji; More preferably, the inoculation amount of the seed koji is such that the initial content of Aspergillus oryzae spores in the second mixed material is 1×10 8 Up to 3×10 8 cfu / g.

3. The method according to claim 2, wherein: The step of preparing the koji further includes: before cooking, mixing peanut meal, soybean meal and water for a third time, and then mixing the third mixed material with oat flakes for a fourth time, wherein the material obtained by the fourth mixing is used for cooking, wherein the mass of water used for the third mixing is 0.8-1.2 times the total mass of the peanut meal, soybean meal and oat flakes; Preferably, the step of preparing the koji further comprises: cooling the steamed raw materials before mixing them with the seed koji, preferably cooling them to 35-42°C.

4. The method according to claim 2 or 3, wherein: The culturing method includes: subjecting the second mixed material to a first culturing, turning over, and then subjecting the second culturing to a second culturing; Preferably, the first culturing method comprises: culturing at 30-32° C. for 16-20 hours to obtain a first culture product; Preferably, the method of turning over includes: turning over the first culture product for the first time, and turning over the first turned product for the second time after 6-8 hours to obtain a second turned product; Preferably, the second culturing method comprises: culturing the second koji product at 28-30°C for 16-18h.

5. The method according to claim 2 or 3, wherein: For 1kg of raw material, the amount of brine used is 2-2.5L; And / or, the salt concentration in the brine is 18-25 wt %.

6. The method according to claim 1 or 2, wherein: The fermentation further includes temperature control during the fermentation process, wherein the temperature control method includes: firstly performing temperature-raising fermentation, and when the temperature rises to a constant temperature, performing constant temperature fermentation until the fermentation ends; Preferably, the starting temperature is 13-16°C; Preferably, the heating rate of the heating fermentation is 0.8-1.5°C / day; Preferably, the constant temperature is 29-31°C; And / or, the total fermentation time is 170-190 days.

7. The method according to claim 1, wherein: The fermentation method includes: inoculating fermentation agent A into the first mixed material to perform a first-stage fermentation to obtain a first-stage fermentation liquid; then inoculating fermentation agent B into the first-stage fermentation liquid to perform a second-stage fermentation to obtain a second-stage fermentation liquid; then inoculating fermentation agent C into the second-stage fermentation liquid to perform a third-stage fermentation; Preferably, on the 10th to 20th day of fermentation, fermentation agent A is inoculated into the fermentation broth; Preferably, on the 28th to 35th day of fermentation, fermentation agent B is inoculated into the fermentation broth; Preferably, on day 90-100 of fermentation, starter culture C is inoculated into the fermentation broth.

8. The method according to claim 1 or 7, wherein: Starter A is Tetragenococcus halophilus; and / or, the fermentation agent B is Kluyveromyces, Saccharomyces rouxii and Saccharomyces cerevisiae, and the Kluyveromyces is preferably Kluyveromyces marxianus; Preferably, the inoculation amounts of Saccharomyces rouxii, Saccharomyces kluyveromyces and Saccharomyces cerevisiae are such that the ratio of their initial viable counts in the two-stage fermentation system is 1:(1.8-2.2):(1.8-2.2); And / or, the starter C further comprises acetic acid bacteria; preferably, the lactic acid bacteria is Lactobacillus plantarum; Preferably, the fermentation agent C is acetic acid bacteria and Lactobacillus plantarum, and preferably the inoculation amount of the acetic acid bacteria and Lactobacillus plantarum is such that the initial viable cell count ratio in the three-stage fermentation system is 1:(0.8-1.2).

9. The method according to claim 1 or 7, wherein: The inoculation amount of starter A is such that its initial content in the first stage fermentation system is 8×10 5 to 1.5×10 6 cfu / g; And / or, the inoculation amount of starter B is such that its initial total content in the second-stage fermentation system is 1×10 6 Up to 1×10 7 cfu / g; And / or, the inoculation amount of the fermentation agent C is such that its initial content in the three-stage fermentation system is 1×10 5 Up to 3×10 5 cfu / g.

10. Soy sauce prepared by the method according to any one of claims 1 to 9; Preferably, the content of aflatoxin B1 in the soy sauce is ≤5 μg / kg.

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