阅读说明：本技术 一种高鲜酱油及其酿造方法 (High-fresh soy sauce and brewing method thereof ) 是由 黄磊 刘翔 周其洋 于 2021-07-30 设计创作，主要内容包括：本发明公开了一种高鲜酱油的酿造方法,包括：取黄豆,浸泡,沥水后避光培养至萌发状态,得到发芽黄豆；将所述发芽黄豆蒸煮至熟,冷却至40℃以下,得到熟豆；取小麦,浸泡,沥水后避光培养至萌发状态,得到发芽小麦；将所述发芽小麦烘干,粉碎,得到小麦粉；将所述熟豆与所述小麦粉混合,接入曲种,拌料均匀,通风培养制曲；将曲料与盐水混合,晒制发酵,发酵过程中加入酵母,发酵完成后,压榨,得到发酵原油；将所述发酵原油进行灭菌、沉淀、过滤和调配,制得酱油。本发明利用萌发的黄豆和小麦进行制曲,提高了原料利用率,也提高了酱油的理化品质和整体风味,使其鲜味更突出,醇香更浓郁,口感更协调,酿造方法容易实施,更适合规模化应用。(The invention discloses a brewing method of high-fresh soy sauce, which comprises the following steps: soaking soybeans, draining water, and culturing in a dark place until the soybeans germinate to obtain germinated soybeans; cooking the germinated soybeans to be cooked, and cooling to below 40 ℃ to obtain cooked soybeans; soaking wheat, draining, and culturing in dark to germinate state to obtain germinated wheat; drying the germinated wheat, and crushing to obtain wheat flour; mixing the cooked beans and the wheat flour, inoculating yeast seeds, uniformly stirring, and performing ventilation culture for yeast preparation; mixing the yeast material with saline water, performing sun-curing fermentation, adding yeast during the fermentation process, and squeezing after the fermentation is finished to obtain fermented crude oil; and sterilizing, precipitating, filtering and blending the fermented crude oil to obtain the soy sauce. According to the invention, the germinated soybeans and the wheat are utilized for starter propagation, so that the utilization rate of raw materials is improved, the physical and chemical quality and the overall flavor of the soy sauce are also improved, the delicate flavor of the soy sauce is more prominent, the mellow flavor is more intense, the mouthfeel is more coordinated, the brewing method is easy to implement, and the soy sauce is more suitable for large-scale application.)

1. The brewing method of the high fresh soy is characterized by comprising the following steps:

soaking soybeans, draining water, and culturing in a dark place until the soybeans germinate to obtain germinated soybeans;

cooking the germinated soybeans to be cooked, and cooling to below 40 ℃ to obtain cooked soybeans;

soaking wheat, draining, and culturing in dark to germinate state to obtain germinated wheat;

drying the germinated wheat, and crushing to obtain wheat flour;

mixing the cooked beans and the wheat flour, inoculating yeast seeds, uniformly stirring, and performing ventilation culture for yeast preparation;

mixing the yeast material with saline water, performing sun-curing fermentation, adding yeast during the fermentation process, and squeezing after the fermentation is finished to obtain fermented crude oil;

and sterilizing, precipitating, filtering and blending the fermented crude oil to obtain the soy sauce.

2. The method for brewing the fresh soy sauce according to claim 1, wherein the germinated soybeans are cultured under conditions of 16-30 ℃ in the absence of light for 35-75 hours;

the culture condition of the germinated wheat is that the germinated wheat is cultured for 48-72 hours at 20-35 ℃ in a dark place.

3. The method for brewing the high-fresh soy sauce according to claim 1, wherein the 60 mesh sieve fraction of the wheat flour is 80% or more;

in the starter propagation, the addition amount of wheat flour is 10-30% of the mass of the soybeans.

4. The method for brewing the fresh soy sauce according to claim 1, wherein the amount of the koji is 0.01 to 0.6% by mass of the total mass of the raw materials.

5. The method for brewing the fresh soy sauce according to claim 1, wherein the conditions for preparing the koji are as follows: the temperature of the yeast culture is controlled to be 25-40 ℃, the air frequency is controlled to be 15-50 Hz, and the culture time is controlled to be 20-35 h.

6. The method for brewing the fresh soy sauce according to claim 1, wherein the temperature of the brine is 20 to 35 ℃, the mass fraction of the brine is 20 to 24%, and the addition amount of the brine is 1.5 to 2.5 times of the total mass of the raw materials.

7. The method for brewing the fresh soy sauce according to claim 1, wherein the sun fermentation time is 30 to 60 days, and wherein the yeast is added after 20 to 40 days of fermentation.

8. The method for brewing the fresh soy sauce according to claim 7, wherein the sun fermentation time is 50 to 60 days, and wherein the yeast is added after 20 to 28 days of fermentation.

9. The method for brewing the fresh soy sauce according to claim 1, wherein the yeast is Saccharomyces rouxii, and the concentration of the yeast is 5X 10²～5×10⁴CFU/mL。

10. A fresh soy sauce, which is brewed by the method for brewing a fresh soy sauce according to any one of claims 1 to 9.

Technical Field

The invention belongs to the technical field of food fermentation, and particularly relates to high-fresh soy sauce and a brewing method thereof.

Background

The brewing process of soy sauce is characterized by that it uses soybean or soybean cake and other plant protein as main raw material, and uses flour, wheat flour or bran and other starch raw material as auxiliary material, and adopts the processes of making yeast and fermentation so as to form the invented flavouring material with good colour, fragrance and taste. The soy sauce has complicated components, and contains various amino acids, saccharides, organic acids, pigments, polypeptides, etc. in addition to salt. The soy sauce is reddish brown in color and has special salty taste, delicate flavor and fragrance. When the food is cooked, a certain amount of soy sauce is added, so that the color of the food can be improved, the fragrance of the food can be enhanced, the flavor of the food can be increased, the dish can better meet the sensory enjoyment of people, and the appetite can be promoted.

Among them, the high-fresh soy sauce is increasingly popular among people due to the characteristics of fresh increasing and strong aroma enhancing functions. In the prior art, CN201910361038.4 discloses a brewing method of high-freshness organic soy sauce, which reduces the starch content by preprocessing wheat, adds polypeptide oligosaccharide enzymatic hydrolysate and polypeptide maltose enzymatic hydrolysate obtained by hydrolysis in the raw material processing stage and the yellow falling fermentation stage respectively, and provides higher substrate concentration by improving the concentration of glutamic acid in the raw materials so as to realize high freshness. CN201410368087.8 discloses that a high-fresh sauce with glutamic acid content higher than 30g/L is obtained by inoculating high-yield glutaminase microorganisms in a starter propagation stage to obtain a high-glutaminase-containing protein starter and fermenting. However, although the method can increase the content of the delicate flavor substances of the soy sauce to a certain extent, the method cannot fully utilize the own enzyme systems of the soybeans and the wheat, so that the protein utilization rate is low, the overall flavor of the soy sauce is thin, the mellow flavor is insufficient, and the coordination degree is still insufficient. Even more, some processes are complicated, for example, large-scale heat exchange is required for the sauce mash, and large-scale application in production enterprises is difficult.

Disclosure of Invention

In order to solve the defects in the prior art, the invention aims to provide the high fresh soy sauce and the brewing method thereof.

In order to realize the purpose, the technical scheme adopted by the invention is as follows:

a brewing method of high-fresh soy sauce comprises the following steps:

soaking soybeans, draining water, and culturing in a dark place until the soybeans germinate to obtain germinated soybeans;

cooking the germinated soybeans to be cooked, and cooling to below 40 ℃ to obtain cooked soybeans;

soaking wheat, draining, and culturing in dark to germinate state to obtain germinated wheat;

drying the germinated wheat, and crushing to obtain wheat flour;

mixing the cooked beans and the wheat flour, inoculating yeast seeds, uniformly stirring, and performing ventilation culture for yeast preparation;

mixing the yeast material with saline water, performing sun-curing fermentation, adding yeast during the fermentation process, and squeezing after the fermentation is finished to obtain fermented crude oil;

and sterilizing, precipitating, filtering and blending the fermented crude oil to obtain the soy sauce.

The sprouted grain contains unique nutrient components beneficial to human body, and is a good nutritional food. The invention utilizes the germinated soybeans and the germinated wheat as the raw materials for brewing the soy sauce, and can enrich the nutritional ingredients of the soy sauce. Meanwhile, the inventor finds that the self-decomposition effect of the soybeans and the wheat can be improved by using the germinated soybeans and the germinated wheat for starter propagation through experimental study, the self enzyme systems of the soybeans and the wheat are fully utilized, the raw material utilization rate is improved, the overall flavor of the soy sauce is improved, and the soy sauce is outstanding in delicate flavor, mellow and rich and harmonious in taste.

The following are material comparisons of soybeans before and after germination:

the data in the table show that the content of protein, total sugar and fat in the germinated soybeans is not changed greatly, but the content of soluble protein is increased, wherein the content of free amino acid represented by necessary amino acid is obviously improved, and the increase reaches 290%, so that the situation is caused because the enzyme activity system of the soybean is activated in the germination process, insoluble macromolecular protein is hydrolyzed into low-molecular protein or amino acid, and the utilization rate of the protein is improved.

Preferably, the soybeans are non-transgenic soybeans.

Preferably, the method for soaking the soybeans comprises the following steps: after removing impurities, stones, color sorting and cleaning, adding water with the temperature of 25-50 ℃ to soak soybeans for 4-10 hours, wherein the adding amount of the water is 1.5-3.5 times of the mass of the soybeans, and soaking until the soybean cores are full without shriveling and wrapping beans.

Preferably, the culture condition of the germinated soybeans is that the germinated soybeans are cultured for 35-75 h at 16-30 ℃ in a dark place.

Preferably, the method for soaking the wheat comprises the following steps: after removing impurities, stones, selecting colors and cleaning the wheat, adding water with the temperature of 25-50 ℃ to soak the wheat for 2-5 hours, wherein the adding amount of the water is 1.0-2.5 times of the mass of the wheat, and soaking the wheat until the wheat is full and does not shrink.

Preferably, the culture condition of the germinated wheat is that the germinated wheat is cultured for 48-72 hours at 20-35 ℃ in a dark place.

Preferably, the drying temperature of the germinated wheat is 100-150 ℃.

Preferably, the 60-mesh screening rate of the wheat flour is more than or equal to 80 percent.

Preferably, in the starter propagation, the addition amount of the wheat flour is 10-30% of the mass of the soybeans.

Preferably, the inoculation amount of the yeast seeds is 0.01-0.6% of the total mass of the raw materials. It is to be understood that the total mass of the raw materials refers to the sum of the mass of the soybeans and the added wheat flour, as follows. The starter propagation process requires that the starter material is uniform and loose and has uniform thickness.

Preferably, the conditions for making the koji are as follows: the temperature of the yeast culture is controlled to be 25-40 ℃, the air frequency is controlled to be 15-50 Hz, and the culture time is controlled to be 20-35 h.

The starter propagation is carried out under the conditions of the invention, so that starter material more suitable for soy sauce fermentation can be obtained, and the quality of soy sauce is improved.

Preferably, the temperature of the brine is 20-35 ℃, the mass fraction is 20-24%, and the addition amount is 1.5-2.5 times of the total mass of the raw materials. The salt content of the fermentation system can affect the fermentation effect, and further affect the soy sauce quality. The salt content of the condition control system is used, the fermentation effect is good, the obtained soy sauce has high quality and outstanding delicate flavor.

Preferably, the sun-curing fermentation time is 30-60 days, wherein yeast is added after 20-40 days of fermentation.

More preferably, the sun-curing fermentation time is 50-60 days, wherein yeast is added after 20-28 days of fermentation.

Preferably, the yeast is Saccharomyces rouxii added in an amount of 5X 10²～5×10⁴CFU/mL. In the preparation method, the saccharomyces rouxii is inoculated for fermentation in the process of starter propagation, so that the accumulation of alcohol substances in the fermentation process can be improved, the flavor of the soy sauce is further improved by utilizing the metabolism of the yeast, and the mellow flavor of the soy sauce is stronger.

The invention also provides the high fresh soy sauce which is brewed by adopting the brewing method of the high fresh soy sauce.

Compared with the prior art, the invention has the beneficial effects that: according to the invention, the germinated soybeans and the wheat are utilized for starter propagation, and the optimization and adjustment of the starter propagation process are combined, so that the physical and chemical quality and the overall flavor of the soy are effectively improved, the delicate flavor of the soy is more prominent, the mellow flavor is more intense, the mouthfeel is more coordinated, and the utilization rate of raw materials is also improved. In addition, the saccharomyces rouxii is inoculated in the fermentation process, so that the accumulation of alcohol substances in the fermentation process is further increased, and the promotion effect on improving the whole fragrance of the soy sauce is achieved. Compared with the mode of complementing the taste of the soy sauce by the additives in the prior art, the brewing method disclosed by the invention is more green and healthy, the obtained soy sauce is lower in reducing sugar content, better in taste harmony, richer in flavor, higher in raw material utilization rate, easier to implement and more suitable for large-scale application.

Detailed Description

To better illustrate the objects, aspects and advantages of the present invention, the present invention is further illustrated by the following examples. It is apparent that the following examples are only a part of the embodiments of the present invention, and not all of them. It should be understood that the embodiments of the present invention are only for illustrating the technical effects of the present invention, and are not intended to limit the scope of the present invention. Unless otherwise specified, the methods employed in the examples of the present invention are all conventional methods in the art, and the instruments, equipment, etc. used are all conventional in the art, and may be prepared by existing methods or commercially available. The percentages in the examples are by weight unless otherwise specified. In the embodiment, sun-curing fermentation is carried out in a fermentation sun-curing pool or a fermentation sun-curing tank, soybeans are cooked by a rotary high-pressure cooking pot or a continuous cooking machine, and a koji-making device adopts a flat-bed ventilation koji-making device or a rotary disc koji-making machine. The koji mold used in the examples and comparative examples was Aspergillus oryzae of the same strain.

Example 1

A brewing method of high-fresh soy sauce comprises the following steps:

(1) bean treatment: taking non-transgenic soybeans, removing impurities, stones, selecting colors and cleaning, putting the soybeans into a soaking tank, adding water with the mass 2 times of that of the soybeans and at 40 ℃, and soaking for 4 hours to ensure that the soybean cores are full and the soybeans are not shriveled or covered with beans;

(2) germinating soybeans: draining the soaked soybeans, and placing the soybeans in an environment with the temperature of 30 ℃ for light-proof culture for 70h to obtain germinated soybeans;

(3) and (3) cooking: steaming germinated soybean to cooked, cooling to below 40 deg.C to obtain cooked soybean, wherein the cooked soybean is not half-cooked, sticky, lumpy, moderate in hardness, complete in bean granule, and has inherent color and fragrance of cooked material;

(4) wheat germination: removing impurities, stones, selecting colors and cleaning wheat, putting the wheat into a soaking tank, adding water with the mass of 1.7 times of that of the wheat and the temperature of 30 ℃, and soaking for 4 hours to ensure that the wheat is full and is not shrunken; draining off water from the soaked wheat, and storing the thin layer in an environment at 30 ℃ in a dark place for 72 hours to obtain germinated wheat;

(5) drying and crushing: drying germinated wheat at 120 deg.C, pulverizing, and sieving with 60 mesh sieve at a rate of 80% or more to obtain wheat flour;

(6) inoculating and mixing materials: mixing cooked beans and wheat flour, wherein the addition amount of the wheat flour is 30% of the mass of soybeans, inoculating yeast seeds accounting for 0.05% of the total mass of the raw materials in the process of stirring by an auger, uniformly stirring the materials by the auger, and then inputting the mixed raw materials into a culture chamber through a conveying belt for ventilation and yeast making;

(7) ventilating and yeast making: controlling the temperature of a yeast culture product to be 25-40 ℃, controlling the air frequency to be 15-50 Hz, controlling the culture time to be 24h, and requiring the yeast culture to be uniform and loose and uniform in thickness in the yeast preparation process;

(8) fermentation: after the yeast material is cultured, mixing the yeast material with saline water at 22 deg.C with the mass fraction of 21%, wherein the addition amount of saline water is 2.0 times of the total mass of the raw materials, sun-drying and fermenting for 60 days, wherein the ratio of 5 × 10 is 5 × 10 after fermenting for 25 days³Adding the Saccharomyces rouxii in the amount of CFU/mL, and squeezing after fermentation to obtain fermented crude oil;

(9) blending: sterilizing the fermented crude oil, precipitating, filtering and blending to obtain the soy sauce.

Example 2

A brewing method of high-fresh soy sauce comprises the following steps:

(1) bean treatment: taking non-transgenic soybeans, removing impurities, stones, selecting colors and cleaning, putting the soybeans into a soaking tank, adding 30 ℃ water with the mass of 2.2 times of that of the soybeans, and soaking for 7 hours to ensure that the soybean cores are full and the soybeans are not shriveled or covered with beans;

(2) germinating soybeans: draining the soaked soybeans, and placing the soybeans in an environment at 25 ℃ for light-proof culture for 75h to obtain germinated soybeans;

(3) and (3) cooking: steaming germinated soybean to cooked, cooling to below 40 deg.C to obtain cooked soybean, wherein the cooked soybean is not half-cooked, sticky, lumpy, moderate in hardness, complete in bean granule, and has inherent color and fragrance of cooked material;

(4) wheat germination: removing impurities, stones, selecting colors and cleaning wheat, putting the wheat into a soaking tank, adding 35 ℃ water with the mass of 1.5 times of that of the wheat, and soaking for 4 hours to ensure that the wheat is full and is not shrunken; draining off water from the soaked wheat, and storing the thin layer in an environment at 30 ℃ in a dark place for 72 hours to obtain germinated wheat;

(5) drying and crushing: drying germinated wheat at 120 deg.C, pulverizing, and sieving with 60 mesh sieve at a rate of 80% or more to obtain wheat flour;

(6) inoculating and mixing materials: mixing cooked beans and wheat flour, wherein the addition amount of the wheat flour is 30% of the mass of soybeans, inoculating yeast seeds accounting for 0.05% of the total mass of the raw materials in the process of stirring by an auger, uniformly stirring the materials by the auger, and then inputting the mixed raw materials into a culture chamber through a conveying belt for ventilation and yeast making;

(7) ventilating and yeast making: controlling the temperature of a yeast culture product to be 25-40 ℃, controlling the air frequency to be 15-50 Hz, controlling the culture time to be 30h, and requiring the yeast culture to be uniform and loose and uniform in thickness in the yeast preparation process;

(8) fermentation: mixing the yeast material with saline water at 25 deg.C with the addition amount of 21% of saline water 2.0 times of the total weight of the raw materials, sun-drying and fermenting for 55 days, wherein the ratio of 5 × 10 is 5 × 10 after fermenting for 20 days³Adding the Saccharomyces rouxii in the amount of CFU/mL, and squeezing after fermentation to obtain fermented crude oil;

(9) blending: sterilizing the fermented crude oil, precipitating, filtering and blending to obtain the soy sauce.

Example 3

A brewing method of high-fresh soy sauce comprises the following steps:

(1) bean treatment: taking non-transgenic soybeans, removing impurities, stones, selecting colors and cleaning, putting the soybeans into a soaking tank, adding 35 ℃ water with the mass of 2.2 times of that of the soybeans, and soaking for 7 hours to ensure that the soybean cores are full and the soybeans are not shriveled or covered with beans;

(2) germinating soybeans: draining the soaked soybeans, and placing the soybeans in an environment with the temperature of 30 ℃ for light-proof culture for 60 hours to obtain germinated soybeans;

(3) and (3) cooking: steaming germinated soybean to cooked, cooling to below 40 deg.C to obtain cooked soybean, wherein the cooked soybean is not half-cooked, sticky, lumpy, moderate in hardness, complete in bean granule, and has inherent color and fragrance of cooked material;

(4) wheat germination: removing impurities, stones, selecting colors and cleaning wheat, putting the wheat into a soaking tank, adding water with the mass of 1.5 times of that of the wheat and the temperature of 37 ℃, and soaking for 4 hours to ensure that the wheat is full and is not shrunken; draining off water from the soaked wheat, and storing the thin layer in a 28 ℃ environment in a dark place for 72 hours to obtain germinated wheat;

(5) drying and crushing: drying germinated wheat at 120 deg.C, pulverizing, and sieving with 60 mesh sieve at a rate of 80% or more to obtain wheat flour;

(6) inoculating and mixing materials: mixing cooked beans and wheat flour, wherein the addition amount of the wheat flour is 30% of the mass of soybeans, inoculating yeast seeds accounting for 0.05% of the total mass of the raw materials in the process of stirring by an auger, uniformly stirring the materials by the auger, and then inputting the mixed raw materials into a culture chamber through a conveying belt for ventilation and yeast making;

(7) ventilating and yeast making: controlling the temperature of a yeast culture product to be 25-40 ℃, controlling the air frequency to be 15-50 Hz, controlling the culture time to be 35h, and requiring the yeast culture to be uniform and loose and uniform in thickness in the yeast preparation process;

(8) fermentation: mixing the yeast material with saline water at 25 deg.C with the addition amount of 21% of saline water 2.0 times of the total weight of the raw materials, sun-drying and fermenting for 55 days, wherein the ratio of 5 × 10 is 5 × 10 after fermenting for 35 days³Adding the Saccharomyces rouxii in the amount of CFU/mL, and squeezing after fermentation to obtain fermented crude oil;

(9) blending: sterilizing the fermented crude oil, precipitating, filtering and blending to obtain the soy sauce.

Comparative example 1

A brewing method of fresh soy sauce is different from the brewing method of the fresh soy sauce in the embodiment 1 only in the adding time of the Saccharomyces rouxii, and comprises the following specific steps:

(1) bean treatment: taking non-transgenic soybeans, removing impurities, stones, selecting colors and cleaning, putting the soybeans into a soaking tank, adding water with the mass 2 times of that of the soybeans and at 40 ℃, and soaking for 4 hours to ensure that the soybean cores are full and the soybeans are not shriveled or covered with beans;

(2) germinating soybeans: draining the soaked soybeans, and placing the soybeans in an environment with the temperature of 30 ℃ for light-proof culture for 70h to obtain germinated soybeans;

(3) and (3) cooking: steaming germinated soybean to cooked, cooling to below 40 deg.C to obtain cooked soybean, wherein the cooked soybean is not half-cooked, sticky, lumpy, moderate in hardness, complete in bean granule, and has inherent color and fragrance of cooked material;

(4) wheat germination: removing impurities, stones, selecting colors and cleaning wheat, putting the wheat into a soaking tank, adding water with the mass of 1.7 times of that of the wheat and the temperature of 30 ℃, and soaking for 4 hours to ensure that the wheat is full and is not shrunken; draining off water from the soaked wheat, and storing the thin layer in an environment at 30 ℃ in a dark place for 72 hours to obtain germinated wheat;

(5) drying and crushing: drying germinated wheat at 120 deg.C, pulverizing, and sieving with 60 mesh sieve at a rate of 80% or more to obtain wheat flour;

(6) inoculating and mixing materials: mixing cooked beans and wheat flour, wherein the addition amount of the wheat flour is 30% of the mass of soybeans, inoculating yeast seeds accounting for 0.05% of the total mass of the raw materials in the process of stirring by an auger, uniformly stirring the materials by the auger, and then inputting the mixed raw materials into a culture chamber through a conveying belt for ventilation and yeast making;

(7) ventilating and yeast making: controlling the temperature of a yeast culture product to be 25-40 ℃, controlling the air frequency to be 15-50 Hz, controlling the culture time to be 24h, and requiring the yeast culture to be uniform and loose and uniform in thickness in the yeast preparation process;

(8) fermentation: after the yeast material is cultured, mixing the yeast material with saline water at 22 deg.C with the mass fraction of 21%, wherein the addition amount of saline water is 2.0 times of the total mass of the raw materials, sun-drying and fermenting for 60 days, wherein the ratio of 5 × 10 is 5 × 10 after fermenting for 10 days³Adding the Saccharomyces rouxii in the amount of CFU/mL, and squeezing after fermentation to obtain fermented crude oil;

(9) blending: sterilizing the fermented crude oil, precipitating, filtering and blending to obtain the soy sauce.

Comparative example 2

A brewing method of fresh soy sauce is different from the brewing method of the fresh soy sauce in the embodiment 1 only in the adding time of the Saccharomyces rouxii, and comprises the following specific steps:

(1) bean treatment: taking non-transgenic soybeans, removing impurities, stones, selecting colors and cleaning, putting the soybeans into a soaking tank, adding water with the mass 2 times of that of the soybeans and at 40 ℃, and soaking for 4 hours to ensure that the soybean cores are full and the soybeans are not shriveled or covered with beans;

(2) germinating soybeans: draining the soaked soybeans, and placing the soybeans in an environment with the temperature of 30 ℃ for light-proof culture for 70h to obtain germinated soybeans;

(3) and (3) cooking: steaming germinated soybean to cooked, cooling to below 40 deg.C to obtain cooked soybean, wherein the cooked soybean is not half-cooked, sticky, lumpy, moderate in hardness, complete in bean granule, and has inherent color and fragrance of cooked material;

(4) wheat germination: removing impurities, stones, selecting colors and cleaning wheat, putting the wheat into a soaking tank, adding water with the mass of 1.7 times of that of the wheat and the temperature of 30 ℃, and soaking for 4 hours to ensure that the wheat is full and is not shrunken; draining off water from the soaked wheat, and storing the thin layer in an environment at 30 ℃ in a dark place for 72 hours to obtain germinated wheat;

(5) drying and crushing: drying germinated wheat at 120 deg.C, pulverizing, and sieving with 60 mesh sieve at a rate of 80% or more to obtain wheat flour;

(6) inoculating and mixing materials: mixing cooked beans and wheat flour, wherein the addition amount of the wheat flour is 30% of the mass of soybeans, inoculating yeast seeds accounting for 0.05% of the total mass of the raw materials in the process of stirring by an auger, uniformly stirring the materials by the auger, and then inputting the mixed raw materials into a culture chamber through a conveying belt for ventilation and yeast making;

(7) ventilating and yeast making: controlling the temperature of a yeast culture product to be 25-40 ℃, controlling the air frequency to be 15-50 Hz, controlling the culture time to be 24h, and requiring the yeast culture to be uniform and loose and uniform in thickness in the yeast preparation process;

(8) fermentation: after the yeast material is cultured, mixing the yeast material with saline water at 22 deg.C with the mass fraction of 21%, wherein the addition amount of saline water is 2.0 times of the total mass of the raw materials, sun-drying and fermenting for 60 days, wherein the ratio of 5 × 10 is 5 × 10 after fermenting for 45 days³Adding the Saccharomyces rouxii in the amount of CFU/mL, and squeezing after fermentation to obtain fermented crude oil;

(9) blending: sterilizing the fermented crude oil, precipitating, filtering and blending to obtain the soy sauce.

Comparative example 3

A brewing method of soy sauce uses ungerminated soybeans and wheat for brewing, and comprises the following steps:

(1) bean treatment: taking non-transgenic soybeans, removing impurities, stones, selecting colors and cleaning, putting the soybeans into a soaking tank, adding 30 ℃ water with the mass of 2.2 times of that of the soybeans, and soaking for 7 hours to ensure that the soybean cores are full and the soybeans are not shriveled or covered with beans;

(2) and (3) cooking: cooking the soaked soybeans to be cooked, cooling the cooked soybeans to below 40 ℃ to obtain cooked soybeans, wherein the cooked soybeans are required to be non-half-cooked, non-sticky, non-lumping, moderate in hardness, complete in bean granules and have the inherent color and fragrance of cooked materials;

(3) crushing wheat: removing impurities, removing stones, selecting colors and cleaning wheat, drying at 120 ℃, and crushing, wherein the crushed wheat is required to have no whole grains, and the 60-mesh sieving rate is more than or equal to 80 percent, so as to obtain wheat flour;

(4) inoculating and mixing materials: mixing cooked beans and wheat flour, wherein the addition amount of the wheat flour is 30% of the mass of soybeans, inoculating yeast seeds accounting for 0.05% of the total mass of the raw materials in the process of stirring by an auger, uniformly stirring the materials by the auger, and then inputting the mixed raw materials into a culture chamber through a conveying belt for ventilation and yeast making;

(5) ventilating and yeast making: controlling the temperature of a yeast culture product to be 25-40 ℃, controlling the air frequency to be 15-50 Hz, controlling the culture time to be 40h, and requiring the yeast culture to be uniform and loose and uniform in thickness in the yeast preparation process;

(6) fermentation: after the yeast material is cultured, mixing the yeast material with saline water at 25 deg.C with the mass fraction of 21%, wherein the addition amount of saline water is 2.0 times of the total mass of the raw materials, sun-drying and fermenting for 55 days, wherein the addition concentration is 5 × 10 after fermenting for 20 days³Squeezing CFU/mL Saccharomyces rouxii after fermentation to obtain fermented crude oil;

(7) blending: sterilizing the fermented crude oil, precipitating, filtering and blending to obtain the soy sauce.

Comparative example 4

A method for brewing soy sauce, which is different from example 1 only in that: during the fermentation, the Saccharomyces rouxii is not added, and other operations are the same.

Effect testing

The test items were as follows:

(1) and (3) soybean digestibility: see SB/T10319-1999.

(2) Index of yeast material

Moisture content (%): refer to GB 5009.3-2016.

Neutral protease activity (U/g): hydrolysis of casein at 40 ℃ and pH7.2 per gram of koji (dry weight) per minute produced 1. mu.g of tyrosine, defined as a unit of neutral protease activity.

Number of spores (billion/g): see SB/T10315-1999.

(3) Index of fermented crude oil

Total acid content (as lactic acid): refer to GB/T12456-.

Content of amino acid nitrogen: refer to GB 5009.235-2016.

Salt (g/100 mL): reference is made to GB/T5009.39-2003.

Reducing sugar content (g/100 mL): refer to GB 5009.7-2016.

Alcohol content (%): refer to GB 5009.225-2016.

Glutamic acid content (g/L): and (5) detecting by using a microplate reader.

Total nitrogen content (g/100 mL): reference is made to GB 5009.5-2016

Aroma (full score 10, higher score indicates stronger aroma).

Mouthfeel (10 points full, higher score indicates better mouthfeel).

(1) The digestibility of soybeans by the brewing methods of examples 1 to 3 and comparative example 3 was tested, and the results were as follows:

digestibility of soybean

Item	Example 1	Example 2	Example 3	Comparative example 3
					Digestibility (%)	87	91	88	82

As can be seen from the data in the table above, the digestibility of the soybeans in the examples 1 to 3 is obviously higher than that in the comparative example 3. The invention adopts the germinated soybeans for brewing, so that the utilization rate of the raw materials can be better improved.

(2) The indexes of the fermented crude oils obtained in examples 1 to 3 and comparative examples 1 to 4 were measured, and the results were as follows:

fermented crude oil

As can be seen from the data in the table, the reducing sugar content of the examples 1-3 is obviously lower than that of the comparative examples 3 and 4, the alcoholic strength is higher, and the diffusible fragrance is obviously enhanced. In examples 1-3 and comparative examples 1-2, the zygosaccharomyces rouxii is added for fermentation at 10, 20, 25, 35 and 45 days respectively, although the alcoholic strength and the aroma can be generated, the total acidity, the aroma and the mouthfeel are influenced by different adding time of the zygosaccharomyces rouxii; if the alcohol is added in advance (namely, the comparative example 1), ester fragrance is slowly generated due to early generation of the alcohol, but the total acid content is low, and the richness of the mouthfeel is reduced; if the addition is late (i.e. comparative example 2), the residual amount of reducing sugar is large, the total acid of fermentation is high, and the sour taste is prominent.

The glutamic acid content and total nitrogen content of examples 1 to 3 were higher than those of comparative examples 1 to 4, which shows that the soy sauce of examples 1 to 3 can provide a richer texture. The evaluation result is also consistent with the detection data, and the taste and the fragrance intensity are all improved.

Finally, it should be noted that the above embodiments are only used for illustrating the technical solutions of the present invention and not for limiting the protection scope of the present invention, and although the present invention is described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that modifications or equivalent substitutions can be made on the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.