CN115553450A - Soy sauce and its preparation method - Google Patents

Abstract

The application provides a preparation method of soy sauce, which comprises the following steps: providing raw materials for preparing soy sauce; adding aspergillus into the raw materials for starter propagation, and adding cellulase in the starter propagation process to obtain finished starter; adding salt water into the finished koji to prepare fermented glutinous rice to obtain fermented glutinous rice and fermenting the fermented glutinous rice; when the pH value of the sauce mash is fermented to 6.30-6.50, neutral protease and amylase are added into the sauce mash and fermentation is continued; when the pH value of the sauce mash is fermented to 5.10-5.50, adding glutaminase and acid protease into the sauce mash and continuing to ferment; when the pH value of the sauce mash is fermented to 4.90-5.20, adding glutaminase again and continuing to ferment to obtain finished mash; and carrying out solid-liquid separation on the finished mash to obtain the soy sauce. The application further provides soy sauce prepared by the preparation method. The preparation method of the soy sauce can effectively improve the yield of the total nitrogen glutamic acid in soy sauce unit and improve the flavor of the brewed soy sauce.

Description

Soy sauce and its preparation method

technical field

The application relates to the technical field of food fermentation engineering, in particular to a soy sauce and a preparation method thereof.

Background technique

Soy sauce is made from raw materials such as soybeans and wheat, which are pressed and sterilized after being fermented by aspergillus, yeast, bacteria and other microorganisms to secrete various enzyme systems. During the brewing process of soy sauce, glutamic acid, as the free amino acid that is the main component of taste, mainly comes from the following three sources: ① The dissolution of raw material protein; ② Biochemical synthesis of microbial glutamic acid; ③ Microbial autolysis, the source ① As the main source, raw gluten is decomposed into peptone, polypeptide, low peptide and other substances by protease, and then glutamic acid is generated by glutaminase.

Soybean protein content is 35% to 40%, of which 21% is gluten, wheat protein content is 10% to 15%, and gluten accounts for 30%. Therefore, the yield of total nitrogen glutamic acid per unit of calculation from raw materials is about 1.35% ~1.46. In "Soy Sauce Science and Brewing Technology", it is introduced that the total nitrogen glutamic acid yield per unit of crude oil fermented by Aspergillus oryzae is 0.80. Soybeans or defatted soybeans, wheat or bran are currently on the market, and the yield of total nitrogen glutamic acid per unit of zero-addition series soy sauce is 0.50-0.90. Therefore, the traditional soy sauce preparation method has the problem of low utilization of raw material gluten, and it is urgent to innovate the process technology to reduce the loss of umami substances in the fermentation process, increase the yield of total nitrogen glutamic acid per unit of soy sauce, and improve the flavor of brewed soy sauce.

At present, the improvement of the traditional soy sauce preparation method is mainly the research on the improvement of glutamic acid brought by the comprehensive enzyme activity, but there are problems such as low efficiency of enzyme activity, high production cost, and unfavorable industrialization promotion.

Contents of the invention

Based on this, it is necessary to provide a soy sauce and a preparation method thereof, so as to increase the yield of total nitrogen glutamic acid per unit of soy sauce and improve the flavor of brewed soy sauce.

The present application provides a kind of preparation method of soy sauce on the one hand, comprises the steps:

Provide raw materials for the preparation of soy sauce;

Add aspergillus to the raw material to make koji, and add cellulase during the koji making process to obtain koji;

adding salt water to the koji to make mash to obtain moromi and fermenting the moromi;

When the moromi is fermented until the pH reaches 6.30-6.50, neutral protease and amylase are added therein and the fermentation is continued;

When the moromi is fermented until the pH reaches 5.10-5.50, glutaminase and acid protease are added therein and the fermentation is continued;

When the moromi is fermented until the pH reaches 4.90-5.20, glutaminase is added thereto again and the fermentation is continued to obtain moromi;

The mash is subjected to solid-liquid separation to obtain soy sauce.

In some of the embodiments, the raw material includes one or more of soybean, wheat, bran, peanut, broad bean, pea, corn, rice and millet.

In some of the embodiments, the Aspergillus comprises one or more of Aspergillus oryzae, Aspergillus niger and Aspergillus sojae.

In some of the embodiments, in the step of adding cellulase during the koji making process, the cellulase is added at 24 hours to 30 hours after the koji making.

In some of the embodiments, the added amount of the cellulase is 0.01‰～0.12‰ of the weight of raw materials for preparing soy sauce.

In some of the embodiments, the added amount of the saline is 1.5-2.0 times of the weight of the koji, and the mass percentage concentration of the saline is 18%-25%.

In some of these embodiments, step (d) meets at least one of the following conditions:

(1) The addition of neutral protease is 0.03‰～0.18‰ of the weight of the sauce mash,

(2) The amount of amylase added is 0.01‰～0.12‰ of the weight of the soy sauce.

In some of these embodiments, step (e) meets at least one of the following conditions:

(1) the add-on of acid protease is 0.04‰～0.25‰ of described soy sauce weight,

(2) The amount of glutaminase added is 0.06‰～0.30‰ of the weight of the soy sauce.

In some of these embodiments, in step (f), the amount of glutaminase added is 0.01‰˜0.15‰ of the weight of the moromi.

In another aspect of the present application, a soy sauce prepared by the method for preparing soy sauce is also provided.

The preparation method of soy sauce provided by this application, according to the characteristics of different enzyme preparations and the characteristics of material changes in the fermentation process of brewing soy sauce, different enzyme preparations are purposely added in the koji making link and fermentation link to enhance the enzyme activity of the fermentation process and realize the high efficiency of the enzyme preparation , so as to increase the yield of total nitrogen glutamic acid per unit and enhance the flavor of soy sauce.

Description of drawings

Fig. 1 is a schematic flow chart of a soy sauce preparation method provided by an embodiment.

detailed description

In order to facilitate the understanding of the present application, the present application will be described more fully below with reference to the relevant drawings. Preferred embodiments of the application are shown in the accompanying drawings. However, the present application can be embodied in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the application more thorough and comprehensive.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the technical field to which this application belongs. The terms used herein in the specification of the application are only for the purpose of describing specific embodiments, and are not intended to limit the application.

Herein, the technical features described in open form include closed technical solutions consisting of the enumerated features, as well as open technical solutions including the enumerated features.

In this article, when it comes to a numerical range, unless otherwise specified, the above-mentioned numerical range is considered continuous, and includes the minimum value and maximum value of the range, and every value between such minimum value and maximum value. Further, when a range refers to an integer, every integer between the minimum and maximum of the range is included. Furthermore, when multiple ranges are provided to describe a feature or characteristic, the ranges may be combined. In other words, unless otherwise indicated, all ranges disclosed herein are to be understood to encompass any and all subranges subsumed therein.

In this article, when referring to the unit of the data range, if there is only a unit after the right endpoint, it means that the units of the left endpoint and the right endpoint are the same. For example, 0.3~0.5m/s means that the units of the left endpoint "0.3" and the right endpoint "0.5" are both m/s (meter/second).

Only certain numerical ranges are specifically disclosed herein. However, any lower limit may be combined with any upper limit to form an unexpressed range; and any lower limit may be combined with any other lower limit to form an unexpressed range, just as any upper limit may be combined with any other upper limit to form an unexpressed range. Furthermore, each individually disclosed point or individual value may serve as a lower or upper limit by itself in combination with any other point or individual value or with other lower or upper limits to form an unexpressly recited range.

If there is no special instruction, all the steps in this application can be carried out sequentially or randomly. For example, the method includes steps (a) and (b), which means that the method may include steps (a) and (b) performed in sequence, and may also include steps (b) and (a) performed in sequence. For example, mentioning that the method may also include step (c) means that step (c) may be added to the method in any order, for example, the method may include steps (a), (b) and (c) , may also include steps (a), (c) and (b), may also include steps (c), (a) and (b) and so on.

Liquid seasonings such as soy sauce are one of the indispensable seasonings in people's lives, and are loved by consumers because of their delicious taste and rich nutrition. However, in the traditional soy sauce preparation method, the umami substances of the raw materials are easily lost during the fermentation process, and the yield of total nitrogen glutamic acid per unit of soy sauce is low, which affects the flavor of soy sauce. The technicians of the present application have found through research that increasing the enzyme activity in the fermentation process can lead to an increase in the yield of total nitrogen glutamic acid per unit.

In related technologies, most of the mixed enzyme preparations are used to improve the enzyme activity in the fermentation process, but the effect on improving the enzyme activity is still very low.

In order to solve the above problems, the application provides a preparation method of soy sauce, please refer to Fig. 1, comprising the following steps:

(a) provide raw materials for the preparation of soy sauce;

(b) adding aspergillus to the raw material to make koji, and adding cellulase during the koji making process to obtain koji;

(c) adding salt water to the koji to make mash to obtain moromi and fermenting the moromi;

(d) when the moromi is fermented until the pH reaches 6.30-6.50, neutral protease and amylase are added therein and the fermentation is continued;

(e) when the moromi is fermented until the pH reaches 5.10-5.50, glutaminase and acid protease are added therein and the fermentation is continued;

(f) when the moromi is fermented until the pH reaches 4.90-5.20, glutaminase is added therein again and the fermentation is continued to obtain moromi;

(g) Separating the mash into solid and liquid to obtain soy sauce.

In the preparation method of soy sauce provided in the examples of this application, cellulase is added during the koji making stage to enhance the effect of the enzyme system on breaking the cell wall of the raw material, creating conditions for the enzyme system such as protease; adding neutral protease and amylase at the beginning of fermentation Enhance the decomposition effect of macromolecular protein substances and increase the content of precursor substances of glutamic acid; add glutaminase and acid protease after fermentation for a certain period of time to increase the production of glutamic acid in the fermentation process; Add glutaminase to keep enough glutaminase in the fermentation process and avoid the formation of tasteless pyroglutamic acid by glutamic acid, thereby effectively increasing the yield of total nitrogen glutamic acid per unit of soy sauce and improving the flavor of brewed soy sauce.

Raw materials for preparing soy sauce may include, but are not limited to, soybeans, wheat, bran, peanuts, broad beans, peas, corn, rice, millet and combinations thereof. Understandably, the ratio of each component in the raw materials for preparing soy sauce can refer to the conventional ratio in the art. For example, in some embodiments, the raw materials for preparing soy sauce are soybeans and wheat, wherein the ratio of soybeans to wheat can be (5-8):(2-5), such as 5:5, 6:4, 7:3 , 8:2.

Further, step (a) may also include the step of pretreating the raw materials for preparing soy sauce. The pretreatment steps can be conventional methods known to those skilled in the art, such as screening, impurity removal, washing, wetting, drying, heat treatment, crushing or grinding, and the like. Wherein, heat treatment may include wet heat treatment, hot air treatment (dry heat treatment), spray drying treatment, superheated steam treatment (atmospheric pressure steam treatment and high pressure steam treatment), extrusion treatment, microwave treatment and infrared heat treatment, etc. Specific heat treatment operations such as cooking, roasting and the like. Understandably, the pretreatment step can be properly selected according to the characteristics of the raw material, and is generally performed according to conventional operations in the art. For example, the operations of pretreating soybeans may include screening, removing impurities, washing, moistening, cooking and crushing, and the operations of pretreating wheat may include screening, removing impurities, washing, drying, roasting and grinding.

The Aspergillus used for making koji may include one or more of Aspergillus oryzae, Aspergillus niger and Aspergillus sojae. In some embodiments, the Aspergillus is Aspergillus oryzae. In other embodiments, the Aspergillus species are Aspergillus oryzae and Aspergillus niger. In some other embodiments, Aspergillus can also be Aspergillus oryzae and Aspergillus sojae. It can be understood that the amount of Aspergillus added can refer to the amount commonly used in the art, for example, usually 0.1% (m/m) to 0.2% (m/m) Aspergillus species are added by weight of raw materials. Understandably, if Aspergillus contains two or more strains, the ratio can refer to the conventional ratio in the art.

In some embodiments, in step (b), in the step of adding cellulase during the koji making process, the cellulase is added at 24 hours to 30 hours after the koji making, which is more conducive to the cell wall breaking effect of the cellulase on the raw material cell wall . Understandably, cellulase can be added to the koji material at any time during 24h, 25h, 26h, 27h, 28h, 29h or 30h of koji making.

In some embodiments, the added amount of cellulase is 0.01‰-0.12‰ of the weight of raw materials for preparing soy sauce. Understandably, the amount of cellulase added can be any value between 0.01‰ and 0.12‰ of the weight of raw materials for preparing soy sauce, for example, also including 0.02‰, 0.03‰, 0.04‰, 0.05‰, 0.06‰, 0.07‰ , 0.08‰, 0.09‰, 0.10‰, 0.11‰.

It is understandable that the adding method of cellulase can be any conventional method in the art, and the method that is convenient for the operation of the subsequent steps and more beneficial to the present application is usually selected. For example, cellulase can be dissolved in water to make a solution for easy addition, and at the same time, the solution can be conveniently sprayed evenly on the raw materials with the help of tools, which is beneficial for the cellulase to act on the raw materials evenly and effectively.

In some embodiments, cellulase is dissolved in water (25°C-35°C) to make a cellulase solution. In step (b), cellulase is added to raw materials in the form of cellulase liquid during the koji making process. Further, the cellulase liquid is evenly sprayed onto the surface of the raw material. Further, the mass percent concentration of cellulase in the cellulase liquid is 1‰˜4‰. Furthermore, the added amount of the cellulase liquid is 1%-3% of the weight of raw materials for preparing soy sauce.

In some embodiments, the amount of saline added is 1.5 to 2.0 times the weight of the koji, and the mass percent concentration of the saline is 18% to 25%. Understandably, the amount of saline added can be any value between 1.5 times and 2.0 times the weight of the koji, for example, 1.6 times, 1.7 times, 1.8 times and 1.9 times are also included. The mass percent concentration of the saline can be any value between 18% and 25%, for example also including 19%, 20%, 21%, 22%, 23%, and 24%.

Understandably, fermenting the moromi until the pH reaches 6.30-6.50 refers to any value between 6.30-6.50, such as 6.35, 6.4, 6.45.

In some embodiments, the amount of neutral protease added is 0.03‰˜0.18‰ of the weight of the moromi. Understandably, the amount of neutral protease added can be any value between 0.03‰ and 0.18‰ of the weight of the soy sauce, for example, 0.05‰, 0.06‰, 0.07‰, 0.08‰, 0.09‰, 0.10‰, 0.12‰ , 0.14‰, 0.16‰.

In some embodiments, the amount of amylase added is 0.01‰˜0.12‰ of the weight of the moromi. Understandably, the amount of amylase added can be any value between 0.01‰ and 0.12‰ of the weight of the soy sauce, for example, it also includes 0.02‰, 0.03‰, 0.04‰, 0.05‰, 0.06‰, 0.07‰, 0.08‰, 0.09‰, 0.10‰, 0.11‰.

It is understandable that the adding method of neutral protease and amylase can be any conventional method in this field, and the method that is convenient for the operation of the subsequent steps and more beneficial to the present application is usually selected. For example, neutral protease and amylase can be dissolved in water to make a solution for easy addition. At the same time, the solution can be conveniently sprayed evenly on the moromi with the help of tools, which is conducive to the uniform and effective effect of neutral protease and amylase on the moromi .

In some embodiments, neutral protease and amylase are dissolved in water (25° C. to 35° C.) to prepare a mixed enzyme solution of neutral protease and amylase. In step (d), neutral protease and amylase are added to the raw material in the form of a mixed enzyme solution of neutral protease and amylase. Further, the mixed enzyme solution of neutral protease and amylase is evenly sprayed onto the surface of the moromi. Further, the mass percent concentration of neutral protease in the mixed enzyme liquid of neutral protease and amylase is 3%-6%, and the mass percent concentration of amylase is 1%-4%. Furthermore, the added amount of the mixed enzyme liquid of neutral protease and amylase is 1‰～3‰ of the weight of the soy sauce.

Understandably, fermenting the moromi until the pH reaches 5.10-5.50 means that the moromi pH is any value between 5.10-5.50, for example also including 5.20, 5.30, 5.40.

In some embodiments, the acid protease is added in an amount of 0.04‰˜0.25‰ of the weight of the moromi. Understandably, the amount of acid protease added can be any value between 0.04‰ and 0.25‰ of the weight of the soy sauce, for example, it also includes 0.05‰, 0.06‰, 0.07‰, 0.08‰, 0.09‰, 0.10‰, 0.12‰, 0.14‰, 0.16‰, 0.18‰.

In some embodiments, the amount of glutaminase added in step (e) is 0.06‰˜0.30‰ of the weight of the soy sauce. Understandably, the amount of glutaminase added can be any value between 0.06‰ and 0.30‰ of the weight of the moromi, for example, 0.07‰, 0.08‰, 0.09‰, 0.10‰, 0.12‰, 0.14‰, 0.16‰ ‰, 0.18‰, 0.20‰, 0.22‰, 0.24‰, 0.26‰, 0.28‰.

It is understandable that the adding method of glutaminase and acid protease in step (e) can be any conventional method in the art, and the method that is convenient for the operation of the subsequent steps and more beneficial to the application is usually selected. For example, glutaminase and acid protease can be dissolved in water to make a solution for easy addition. At the same time, the solution can be conveniently sprayed evenly on the soy sauce with the help of tools, which is conducive to the uniform and effective effect of glutaminase and acid protease on moromi.

In some embodiments, glutaminase and acid protease are dissolved in water (25° C. to 35° C.) to prepare a mixed enzyme liquid of glutaminase and acid protease. In step (e), glutaminase and acid protease are added to the raw material in the form of a mixed enzyme solution of glutaminase and acid protease. Further, the mixed enzyme solution of glutaminase and acid protease is evenly sprayed onto the surface of the moromi. Further, the mass percentage concentration of glutaminase in the mixed enzyme liquid of glutaminase and acid protease is 3%-6%, and the mass percentage concentration of acid protease is 2%-5%. Furthermore, the amount of the mixed enzyme solution of glutaminase and acid protease is 2‰～5‰ of the weight of the soy sauce.

In some embodiments, the amount of glutaminase added in step (f) is 0.01‰˜0.15‰ of the weight of the soy sauce. Understandably, the amount of glutaminase added can be any value between 0.01‰ and 0.15‰ of the weight of the moromi, for example, 0.02‰, 0.04‰, 0.06‰, 0.08‰, 0.10‰, 0.12‰, 0.14‰ ‰.

It is understandable that the method of adding glutaminase in step (f) can be any conventional method in the art, and the method that is convenient for the operation of the subsequent steps and more beneficial to the application is usually selected. For example, glutaminase can be dissolved in water to make a solution for easy addition, and at the same time, the solution can be conveniently sprayed evenly on the moromi with the help of tools, which is beneficial for the glutaminase to act evenly and effectively on the moromi.

In some embodiments, glutaminase solution is prepared by dissolving glutaminase in water (25°C-35°C). In step (f), glutaminase is added to the raw material in the form of glutaminase solution. Further, the glutaminase liquid is evenly sprayed onto the surface of the moromi. Further, the mass percent concentration of glutaminase in the glutaminase enzyme liquid is 0.5%-3%. Furthermore, the amount of glutaminase liquid added is 2‰-5‰ of the weight of the soy sauce.

It is understandable that the method of separating the solid from the mash can be carried out according to conventional operations in the art, for example, separating the soy sauce and the fermented grains by means of plates and frames.

In yet another aspect, the present application further provides the soy sauce prepared by the preparation method of any one of the above-mentioned embodiments.

The following are specific examples. This application is intended to be further described in detail to help those skilled in the art and researchers to further understand this application, and relevant technical conditions and the like do not constitute any limitation on this application. Any form of modification made within the scope of the claims of the present application is within the protection scope of the claims of the present application. The drugs and instruments used in the examples are all routine choices in the art unless otherwise specified. The experimental methods for which specific conditions are not indicated in the examples are implemented according to conventional conditions, such as the conditions described in literature, books or the method recommended by the manufacturer.

Unless otherwise stated, the raw materials and reagents used in the following examples are commercially available or can be prepared by known methods. The experimental methods for which specific conditions are not indicated in the examples are implemented according to conventional conditions, such as the conditions described in literature, books or the method recommended by the manufacturer.

It should be noted that "moisturizing" in the following refers to adding appropriate water to the raw material and making the raw material absorb water evenly. "Wetting ratio" refers to the percentage of the weight of soybeans and the weight of water used in the wetting operation.

Example 1

1. Soybean pretreatment: Soybean screening, impurity removal, moistening (moistening ratio 125%), steaming after completion of moistening, the cooking conditions are 120°C, 0.18MPa, and the cooking time is 90s.

2. Wheat pretreatment: After screening and removing impurities, the wheat is roasted at a temperature of 250°C for 2 minutes. After roasting, the temperature is lowered to 40°C and then milled.

3. Koji making: Mix the pretreated soybeans and wheat flour in steps 1 to 2 evenly to obtain raw materials, and add 0.1% (m/m) Aspergillus oryzae by weight of the raw materials to mix well and make koji.

4. Preparation of enzyme solution A: dissolving cellulase in tap water at 30°C to obtain enzyme solution A, wherein the mass percent concentration of cellulase is 3‰.

5. Enzyme liquid A addition: the enzyme liquid A obtained in step 4 is added to the koji material by spraying after 25 hours of koji making in step 3, and the addition ratio is 2% of the raw material weight, and the cultivation is continued for 20 hours to obtain mature koji material.

6. Make mash: add 2.0 times of salt water to the koji obtained in step 5 by weight to make mash. The concentration of salt water used is 20%, and the pH value of the soy sauce is 6.45.

7. Preparation of enzyme solution B: dissolving neutral protease and amylase in tap water at 30° C. to obtain enzyme solution B, wherein the mass percentage concentrations of neutral protease and amylase are 4% and 2% respectively.

8. Enzyme liquid B addition: Add the enzyme liquid B obtained in step 7 to the moromi prepared in step 6, the addition ratio is 2‰ of the weight of the moromi obtained in step 6, stir for 45 minutes and then carry out the moromi fermentation.

9. Preparation of enzyme solution C: dissolving glutaminase and acid protease in tap water at 30° C. to obtain enzyme solution C, wherein the mass percentage concentrations of glutaminase and acid protease are 4% and 3% respectively.

10. Enzyme liquid C addition: After completing step 8, ferment until 8 days, the pH value of the moromi is 5.40, add the enzyme liquid C obtained in step 9 to the moromi, and the addition ratio is 3‰ of the weight of the moromi obtained in step 6 , continue to ferment after stirring for 45min.

11. Preparation of enzyme solution D: dissolving glutaminase in tap water at 30° C. to obtain enzyme solution D, wherein the mass percent concentration of glutaminase is 2%.

12. Addition of enzyme liquid D: After completing step 10, continue to ferment until 40 days, the pH value of the moromi is 4.95, add the enzyme liquid D obtained in step 11 to the moromi, and the addition ratio is 3‰ of the weight of the moromi obtained in step 6 , continue to ferment after stirring for 45 minutes, and ferment for 65 days to obtain mature moromi.

13. Pressing: the fermented soy mash matured in step 12 is separated from the soy sauce and the soy mash through a frame.

Example 2

The preparation method is basically the same as in Example 1, except that:

The addition ratio of enzyme liquid A is 1.5% of the raw material weight;

The addition ratio of enzyme solution B is 1.5‰ of the weight of soy sauce;

The addition ratio of enzyme liquid C is 2.5‰ of the weight of soy sauce;

The addition ratio of enzyme liquid D is 1‰ of the weight of soy sauce.

Example 3

The preparation method is basically the same as in Example 1, except that:

The addition ratio of enzyme solution A is 3% of the raw material weight;

The addition ratio of enzyme solution B is 3‰ of the weight of the soy sauce;

The addition ratio of enzyme liquid C is 5‰ of the weight of soy sauce;

The addition ratio of enzyme solution D is 3‰ of the weight of soy sauce.

Example 4

The preparation method is basically the same as in Example 1, except that:

Enzyme liquid A addition ratio is 4% of raw material weight;

The addition ratio of enzyme solution B is 4‰ of the weight of soy sauce;

The addition ratio of enzyme liquid C is 6‰ of the weight of soy sauce;

The addition ratio of enzyme liquid D is 4‰ of the weight of soy sauce.

Comparative example 1

1. Soybean pretreatment: Soybean screening, impurity removal, moistening (moistening ratio 125%), steaming after completion of moistening, the cooking conditions are 120°C, 0.18MPa, and the cooking time is 90s.

2. Wheat pretreatment: After screening and removing impurities, the wheat is roasted at a temperature of 250°C for 2 minutes. After roasting, the temperature is lowered to 40°C and then milled.

3. Koji making: Mix the pretreated soybeans and wheat flour in steps 1 to 2 evenly to obtain raw materials, and add 0.1% (m/m) Aspergillus oryzae by weight of the raw materials to mix well and make koji.

4. Make mash: the koji material obtained in step 3 is added into 2.0 times of salt water by weight to make mash. The used salt water concentration for making mash is 20%, and the pH of the soy sauce is 6.88.

5. Fermentation: the mash obtained in step 4 was stirred for 45 minutes every 10 days, and fermented for 65 days to obtain mature mash.

6. Pressing: the fermented soy mash matured in step 5 is separated from soy sauce and soy mash through a frame.

Comparative example 2

1. Soybean pretreatment: Soybean screening, impurity removal, moistening (moistening ratio 125%), steaming after completion of moistening, the cooking conditions are 120°C, 0.18MPa, and the cooking time is 90s.

2. Wheat pretreatment: After screening and removing impurities, the wheat is roasted at a temperature of 250°C for 2 minutes. After roasting, the temperature is lowered to 40°C and then milled.

3. Koji making: Mix the pretreated soybeans and wheat flour in steps 1 to 2 evenly to obtain raw materials, and add 0.1% (m/m) Aspergillus oryzae by weight of the raw materials to mix well and make koji.

4. Make mash: add 2.0 times of salt water to the koji material obtained in step 3 according to the weight, and make mash. The concentration of salt water used is 20%, and the pH value of the soy sauce is 6.45.

5. Preparation of enzyme solution A: dissolving cellulase in tap water at 30°C to obtain enzyme solution A, wherein the mass percent concentration of cellulase is 3‰.

Preparation of enzyme solution B: dissolving neutral protease and amylase in tap water at 30°C to obtain enzyme solution B, wherein the mass percent concentrations of neutral protease and amylase were 4% and 2%, respectively.

Preparation of enzyme solution C: dissolving glutaminase and acid protease in tap water at 30° C. to obtain enzyme solution C, wherein the mass percentage concentrations of glutaminase and acid protease were 4% and 3%, respectively.

Preparation of enzyme solution D: dissolving glutaminase in tap water at 30° C. to obtain enzyme solution D, wherein the mass percent concentration of glutaminase is 2%.

6. Fermentation by adding enzyme liquid: add enzyme liquid A to D prepared in step 5 to the mash obtained in step 4 at the same time, the addition ratio of enzyme liquid A is 2% of the weight of raw materials; the addition ratio of enzyme liquid B is the ratio of step 4 2‰ of the weight of the obtained moromi; the addition ratio of enzyme liquid C is 3‰ of the weight of the moromi obtained in step 4; the addition ratio of enzyme liquid D is 3‰ of the weight of the moromi obtained in step 4, and the moromi is continued after stirring for 45 minutes. Fermentation, fermented for 65 days to obtain mature moromi.

7. Pressing: the fermented soy mash matured in step 6 is separated from soy sauce and soy mash through a frame.

Comparative example 3

1. Soybean pretreatment: Soybean screening, impurity removal, moistening (moistening ratio 125%), steaming after completion of moistening, the cooking conditions are 120°C, 0.18MPa, and the cooking time is 90s.

2. Wheat pretreatment: After screening and removing impurities, the wheat is roasted at a temperature of 250°C for 2 minutes. After roasting, the temperature is lowered to 40°C and then milled.

3. Koji making: Mix the pretreated soybeans and wheat flour in steps 1 to 2 evenly to obtain raw materials, and add 0.1% (m/m) Aspergillus oryzae by weight of the raw materials to mix well and make koji.

4. Preparation of enzyme solution D: dissolving glutaminase in tap water at 30° C. to obtain enzyme solution D, wherein the mass percent concentration of glutaminase is 2%.

5. Enzyme liquid D addition: the enzyme liquid D obtained in step 4 is added to the koji material by spraying after 25 hours of koji making in step 3, and the addition ratio is 2% of the weight of the raw material, and the cultivation is continued for 20 hours to obtain mature koji material.

6. Make mash: add 2.0 times of salt water to the koji obtained in step 5 by weight to make mash. The concentration of salt water used is 20%, and the pH value of the soy sauce is 6.45.

7. Preparation of enzyme solution B: dissolving neutral protease and amylase in tap water at 30° C. to obtain enzyme solution B, wherein the mass percentage concentrations of neutral protease and amylase are 4% and 2% respectively.

8. Enzyme liquid B addition: Add the enzyme liquid B obtained in step 7 to the moromi prepared in step 6, the addition ratio is 2‰ of the weight of the moromi obtained in step 6, stir for 45 minutes and then carry out the moromi fermentation.

9. Preparation of enzyme solution C: dissolving glutaminase and acid protease in tap water at 30° C. to obtain enzyme solution C, wherein the mass percentage concentrations of glutaminase and acid protease are 4% and 3% respectively.

10. Enzyme liquid C addition: After completing step 8, ferment until 8 days, the pH value of the moromi is 5.40, add the enzyme liquid C obtained in step 9 to the moromi, and the addition ratio is 3‰ of the weight of the moromi obtained in step 6 , continue to ferment after stirring for 45min.

11. Preparation of enzyme solution A: dissolving cellulase in tap water at 30°C to obtain enzyme solution A, wherein the mass percent concentration of cellulase is 3‰.

12. Addition of enzyme solution A: After completing step 10, continue to ferment until 40 days, the pH value of the moromi is 4.95, add the enzyme solution A obtained in step 11 to the moromi, and the addition ratio is 3‰ of the weight of the moromi obtained in step 6 , continue to ferment after stirring for 45 minutes, and ferment for 65 days to obtain mature moromi.

13. Pressing: the fermented soy mash matured in step 12 is separated from the soy sauce and the soy mash through a frame.

Comparative example 4

The preparation method is basically the same as in Example 1, except that step 4 and step 5 are omitted, that is, no enzyme solution A is added, and the koji material obtained in step 3 is directly added to 2.0 times the weight of salt water to make mash .

Comparative example 5

The preparation method is basically the same as in Example 1, except that step 11 and step 12 are omitted, that is, no enzyme liquid D is added, and the moromi in step 10 is directly fermented to 65 days to obtain mature moromi, and then the soy sauce is separated by a plate frame and soy sauce.

The soy sauce that embodiment 1～4 and comparative example 1～5 are prepared detects, and detection item and detection method and standard are as follows:

1. Yield of total nitrogen glutamic acid per unit: Yield of total nitrogen glutamic acid per unit = glutamic acid of crude oil / total nitrogen of crude oil, among which total nitrogen of crude oil is based on GB 5009.5-2016 "National Food Safety Standard for the Detection of Protein in Food" No. One method Kjeldahl method; Crude glutamic acid was detected according to the glutamic acid detection kit.

2. Residual protein residue: The residual protein residue is based on the first method of Kjeldahl method in GB 5009.5-2016 "National Food Safety Standard for the Detection of Protein in Food".

The conditions and detection results for preparing soy sauce in Examples 1 to 4 and Comparative Examples 1 to 5 are listed in Table 1 as follows:

Table 1

project Adding order of enzyme solution Addition ratio of enzyme solution A/B/C/D Unit total nitrogen glutamic acid yield Slag residual protein (%) Example 1 A-B-C-D 2%/2‰/3‰/3‰ 1.10 4.5 Example 2 A-B-C-D 1.5%/1.5‰/2.5‰/1‰ 1.00 4.8 Example 3 A-B-C-D 3%/3‰/5‰/3‰ 1.18 4.0 Example 4 A-B-C-D 4%/4‰/6‰/4‰ 1.19 3.9 Comparative example 1 no added / 0.61 7.0 Comparative example 2 Enzyme mixed with 2%/2‰/3‰/3‰ 0.65 6.7 Comparative example 3 D-B-C-A 2%/2‰/3‰/3‰ 0.68 6.8 Comparative example 4 B-C-D 0%/2‰/3‰/3‰ 0.72 7.0 Comparative example 5 A-B-C 2%/2‰/3‰/0‰ 0.83 6.0

It can be seen from Table 1 that the yield per unit of total nitrogen glutamic acid in Examples 1-4 of the present application is significantly better than that in Comparative Examples 1-5.

Comparing Example 1 and Comparative Example 2, the amount of enzyme solution added is the same, and the unit total nitrogen glutamic acid yield of Example 1 is significantly higher than that of Comparative Example 2. Comparing Example 1 and Comparative Example 3, the unit total nitrogen of Example 1 is significantly higher than that of Comparative Example 2. The yield of glutamic acid was significantly higher than that of Comparative Example 3, indicating that the enzyme activity that needs to be enhanced at different stages of the koji-making fermentation process is targeted.

Comparing Example 1 and Comparative Examples 4 to 5, the unit total nitrogen glutamic acid yield of embodiment 1 is also significantly higher than comparative examples 4 to 5, although the unit total nitrogen glutamic acid yield of comparative examples 4 to 5 is relative to The comparison ratio has been improved, but it is still lower than that of Example 1, indicating that the lack of strengthening effect of any one of the enzymes will have an impact on the enzyme activity.

To sum up, it shows that the preparation method of soy sauce provided by the present application can brew soy sauce efficiently and economically, and achieve a significant increase in the yield per unit of total nitrogen glutamic acid.

The various technical features of the above-mentioned embodiments can be combined arbitrarily. For the sake of concise description, all possible combinations of the various technical features in the above-mentioned embodiments are not described. However, as long as there is no contradiction in the combination of these technical features, should be considered as within the scope of this specification.

The above-mentioned embodiments only express several implementation modes of the present application, and the description thereof is relatively specific and detailed, but should not be construed as limiting the scope of the patent for the invention. It should be noted that those skilled in the art can make several modifications and improvements without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the scope of protection of the patent application should be based on the appended claims.

Claims (10)

1. a preparation method of soy sauce, is characterized in that, comprises the steps: (a) provide raw materials for making soy sauce; (b) adding aspergillus to the raw material to make koji, and adding cellulase during the koji making process to obtain koji; (c) adding salt water to the koji and making mash to obtain moromi and fermenting the moromi; (d) when the moromi is fermented until the pH reaches 6.30-6.50, neutral protease and amylase are added therein and the fermentation is continued; (e) when the moromi is fermented until the pH reaches 5.10-5.50, glutaminase and acid protease are added therein and the fermentation is continued; (f) when the moromi is fermented until the pH reaches 4.90-5.20, glutaminase is added thereto again and the fermentation is continued to obtain moromi; (g) performing solid-liquid separation on the mash to obtain soy sauce. 2. the preparation method of soy sauce according to claim 1 is characterized in that, described raw material comprises one or more in soybean, wheat, bran, peanut, broad bean, pea, corn, rice and millet. 3. the preparation method of soy sauce according to claim 1, is characterized in that, described aspergillus comprises one or more in aspergillus oryzae, aspergillus niger and aspergillus sojae. 4. The preparation method of soy sauce according to claim 1, characterized in that, in the step of adding cellulase during the koji making process, the cellulase is added at 24h to 30h of koji making. 5. The preparation method of soy sauce according to claim 1 or 4, characterized in that, the added amount of the cellulase is 0.01‰～0.12‰ of the raw material weight for preparing soy sauce. 6. The preparation method of soy sauce according to claim 1, characterized in that, the added amount of the saline solution is 1.5 to 2.0 times the weight of the koji, and the mass percent concentration of the saline solution is 18% to 25%. %. 7. the preparation method of soy sauce according to claim 1, is characterized in that, step (d) satisfies at least one in the following conditions: (1) The addition of neutral protease is 0.03‰～0.18‰ of the weight of the sauce mash, (2) The amount of amylase added is 0.01‰～0.12‰ of the weight of the soy sauce. 8. the preparation method of soy sauce according to claim 1, is characterized in that, step (e) satisfies at least one in the following conditions: (1) the add-on of acid protease is 0.04‰～0.25‰ of described soy sauce weight, (2) The amount of glutaminase added is 0.06‰～0.30‰ of the weight of the soy sauce. 9. The preparation method of soy sauce according to claim 1, characterized in that, in the step (f), the amount of glutaminase added is 0.01‰～0.15‰ of the weight of the soy sauce. 10. A soy sauce prepared by the method for preparing soy sauce according to any one of claims 1 to 9.

Images