CN115553450A

CN115553450A - Soy sauce and preparation method thereof

Info

Publication number: CN115553450A
Application number: CN202211309055.1A
Authority: CN
Inventors: 曾敏; 李艳军; 李荔; 桂军强
Original assignee: Foshan Haitian Suqian Seasoning Food Co ltd; Haitian Brewing Food Co ltd; Foshan Haitian Nanning Seasoning Food Co ltd; Foshan Haitian Flavoring and Food Co Ltd; Foshan Haitian Gaoming Flavoring and Food Co Ltd
Current assignee: Foshan Haitian Suqian Seasoning Food Co ltd; Haitian Brewing Food Co ltd; Foshan Haitian Nanning Seasoning Food Co ltd; Foshan Haitian Flavoring and Food Co Ltd; Foshan Haitian Gaoming Flavoring and Food Co Ltd
Priority date: 2022-10-25
Filing date: 2022-10-25
Publication date: 2023-01-03

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 preparation method thereof

Technical Field

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

Background

The soy sauce is prepared by using soybean, wheat and other raw materials, performing comprehensive action of various enzyme systems secreted by various microorganisms such as aspergillus, yeast, bacteria and the like in a fermentation process, and then performing squeezing and sterilization. During the brewing process of soy sauce, glutamic acid is used as free amino acid of a main flavor development component, and the following three sources are mainly provided: (1) the raw material protein is decomposed and dissolved; (2) biochemical synthesis of microbial glutamic acid; (3) the microbial thallus is autolyzed, wherein the source (1) is the main source, the raw material gluten is decomposed into matters such as peptone, polypeptide, oligopeptide and the like through protease, and then glutamic acid is generated through the action of glutaminase.

The soybean protein content is 35-40%, wherein 21% is glutelin, the wheat protein content is 10-15%, and the glutelin accounts for 30%, so the yield of the unit total nitrogen glutamic acid calculated from the raw materials is about 1.35-1.46. In the technology of soy sauce science and brewing, the yield of crude oil per unit of total nitrogen glutamic acid of daqu fermentation of aspergillus oryzae is introduced to be 0.80. Soybean or defatted soybean, wheat or bran are marked on the existing market, and the yield of the total nitrogen glutamic acid of zero-additive series soy sauce unit is 0.50-0.90. Therefore, the traditional soy sauce preparation method has the problem of low utilization rate of gluten serving as a raw material, and the process technology is urgently needed to be innovated, so that the loss of delicate flavor substances of the raw material in the fermentation process is reduced, the yield of the total nitrogen glutamic acid of a soy sauce unit is improved, and the flavor of the brewed soy sauce is improved.

However, the improvement of the traditional soy sauce preparation method at present mainly aims at the research of glutamic acid improvement brought by comprehensive enzyme activity, and has the problems of low enzyme activity effect, high production cost, unfavorable industrial popularization and the like.

Disclosure of Invention

Therefore, there is a need for a soy sauce and a preparation method thereof, which can improve the yield of total nitrogen glutamic acid in soy sauce unit and improve the flavor of brewed soy sauce.

The application provides a preparation method of soy sauce on one hand, 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 moromi, obtaining moromi and fermenting the moromi;

when the pH value of the sauce mash reaches 6.30-6.50, adding neutral protease and amylase into the sauce mash and continuing fermentation;

when the soy sauce mash is fermented until the pH value reaches 5.10-5.50, adding glutaminase and acid protease into the soy sauce mash and continuing fermentation;

when the sauce mash is fermented until the pH value reaches 4.90-5.20, adding glutaminase again and continuing fermentation to obtain finished mash;

and carrying out solid-liquid separation on the finished mash to obtain the soy sauce.

In some of these embodiments, the feedstock comprises one or more of soy, wheat, bran, peanut, broad bean, pea, corn, rice, and millet.

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

In some embodiments, in the step of adding cellulase in the koji making process, the cellulase is added when koji making is carried out for 24-30 h.

In some embodiments, the cellulase is added in an amount of 0.01 to 0.12 per mill of the weight of the raw materials for preparing the soy sauce.

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

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

(1) The addition amount of the neutral protease is 0.03 per mill to 0.18 per mill of the weight of the soy sauce mash,

(2) The addition amount of amylase is 0.01-0.12 per mill of the weight of the sauce mash.

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

(1) The adding amount of the acid protease is 0.04 to 0.25 per mill of the weight of the soy sauce mash,

(2) The adding amount of the glutaminase is 0.06-0.30 per mill of the weight of the soy sauce mash.

In some of these embodiments, in step (f), the glutaminase is added in an amount of 0.01 to 0.15 per thousand by weight of said moromi.

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

According to the preparation method of the soy sauce, different enzyme preparations are purposefully added in the starter propagation link and the fermentation link according to different enzyme preparation characteristics and material change characteristics in the soy sauce brewing fermentation process to enhance the enzyme activity in the fermentation process, so that the high-efficiency action of the enzyme preparation is realized, the unit total nitrogen glutamic acid yield is improved, and the soy sauce flavor is improved.

Drawings

Fig. 1 is a schematic flow chart of a method for preparing soy sauce according to an embodiment.

Detailed Description

To facilitate an understanding of the present application, the present application will now be described more fully with reference to the accompanying drawings. Preferred embodiments of the present application are shown in the drawings. This application may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the description of the present application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

In the technical features described in the open-ended form, the closed technical scheme comprising the listed features also comprises the open technical scheme comprising the listed features.

Herein, reference to numerical intervals is deemed continuous within the numerical intervals, unless otherwise stated, and includes the minimum and maximum values of the range, as well as each and every value between such minimum and maximum values. Further, when a range refers to an integer, each integer between the minimum and maximum values of the range is included. Further, when multiple range-describing features or characteristics are provided, 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 context, referring to units of the data range, if only with units after the right end point, the units representing the left end point and the right end point are the same. For example, 0.3 to 0.5m/s means that the units of the left end point "0.3" and the right end point "0.5" are both m/s (meters/second).

Only a few numerical ranges are specifically disclosed herein. However, any lower limit may be combined with any upper limit to form ranges not explicitly recited; and any lower limit may be combined with any other lower limit to form a range not explicitly recited, and any upper limit may be combined with any other upper limit to form a range not explicitly recited. Further, each separately disclosed point or individual value may itself, as a lower limit or upper limit, be combined with any other point or individual value or with other lower limit or upper limit to form a range not explicitly recited.

All steps of the present application may be performed sequentially or randomly, if not specifically stated. For example, the method comprises steps (a) and (b), meaning that the method may comprise steps (a) and (b) performed sequentially, and may also comprise steps (b) and (a) performed sequentially. For example, reference to the process further comprising step (c) means that step (c) may be added to the process in any order, for example, the process may comprise steps (a), (b) and (c), may also comprise steps (a), (c) and (b), may also comprise steps (c), (a) and (b), etc.

Liquid seasonings such as soy sauce and the like are one of indispensable seasonings in the life of people, and are popular with consumers due to delicious taste and rich nutrition. However, the delicate flavor substances of the raw materials are easy to lose in the fermentation process of the traditional soy sauce preparation method, the yield of per-unit total nitrogen glutamic acid of the soy sauce is low, and the flavor of the soy sauce is influenced. Through research, the technical personnel of the application find that the increase of the enzyme activity in the fermentation process can bring the increase of the unit total nitrogen glutamic acid yield.

In the related technology, enzyme activity in the fermentation process is improved mostly by mixing enzyme preparations, but the effect of improving the enzyme activity is still very low.

In order to solve the above problems, the present application provides a method for preparing soy sauce, referring to fig. 1, comprising the steps of:

(a) Providing raw materials for preparing soy sauce;

(b) Adding aspergillus into the raw materials for starter propagation, and adding cellulase in the starter propagation process to obtain finished starter;

(c) Adding salt water into the finished koji to prepare fermented glutinous rice, obtaining fermented glutinous rice and fermenting the fermented glutinous rice;

(d) Fermenting the soy sauce mash until the pH value reaches 6.30-6.50, adding neutral protease and amylase into the soy sauce mash, and continuing fermenting;

(e) Fermenting the soy sauce mash until the pH value reaches 5.10-5.50, adding glutaminase and acid protease into the soy sauce mash, and continuing to ferment;

(f) Fermenting the sauce mash until the pH value reaches 4.90-5.20, adding glutaminase again, and continuing to ferment to obtain finished mash;

(g) And carrying out solid-liquid separation on the finished mash to obtain the soy sauce.

According to the preparation method of the soy sauce, the wall breaking effect of the enzyme system on the cell wall of the raw material is enhanced by adding the cellulase in the starter propagation stage, so that action conditions are created for the enzyme systems such as protease; neutral protease and amylase are added when fermentation is started to enhance the decomposition effect of macromolecular protein substances and increase the content of precursor substances of glutamic acid; after fermenting for a certain time, adding glutaminase and acid protease to improve the production of glutamic acid in the fermentation process; after fermentation is carried out under certain conditions, glutaminase is added for the second time, sufficient glutaminase is kept in the fermentation process, and tasteless pyroglutamic acid is prevented from being formed by glutamic acid, so that the yield of total nitrogen glutamic acid in soy sauce unit is effectively improved, and the flavor of brewed soy sauce is improved.

The raw materials for preparing soy sauce may include, but are not limited to, soybean, wheat, bran, peanut, broad bean, pea, corn, rice, millet, and combinations thereof. Understandably, the ratio of each component in the raw materials for preparing the soy sauce can be calculated according to the conventional ratio in the field. For example, in some embodiments, the raw materials from which the soy sauce is made are soy and wheat, wherein the ratio of soy to wheat can be (5-8) to (2-5), e.g., 5.

Further, the step (a) may further comprise a step of pretreating the raw materials for preparing soy sauce. The pretreatment step may be a conventional method known to those skilled in the art, such as screening, impurity removal, washing, moistening, drying, heat treatment, crushing or grinding, and the like. Among them, the heat treatment may include a wet heat treatment, a hot air treatment (dry heat treatment), a spray drying treatment, a superheated steam treatment (atmospheric steam treatment and high-pressure steam treatment), an extrusion treatment, a microwave treatment, an infrared heat treatment, and the like. The specific heat treatment operation is, for example, cooking, roasting, or the like. Understandably, the pretreatment step may be appropriately selected depending on the characteristics of the raw material, and is generally carried out according to the routine procedures in the art. For example, the pretreatment of soybeans may include screening, impurity removal, washing, moistening, cooking, and crushing, and the pretreatment of wheat may include screening, impurity removal, washing, drying, roasting, and grinding.

The aspergillus used for koji making 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 is aspergillus oryzae and aspergillus niger. In still other embodiments, the Aspergillus can also be Aspergillus oryzae and Aspergillus sojae. The amount of Aspergillus may be understandably referred to the amount conventionally used in the art, for example, aspergillus is usually incorporated in an amount of 0.1% (m/m) to 0.2% (m/m) of the species Aspergillus based on the weight of the starting material. Understandably, if the aspergillus contains two or more species, the proportion can refer to the conventional proportion in the field.

In some embodiments, in the step (b), in the step of adding the cellulase in the koji making process, the cellulase is added when the koji making process is carried out for 24-30 hours, so that the wall breaking effect of the cellulase on the cell walls of the raw materials is more favorable. Understandably, the cellulase can be added into the yeast material at any time of preparing the yeast for 24h, 25h, 26h, 27h, 28h, 29h or 30 h.

In some embodiments, the cellulase is added in an amount of 0.01 to 0.12% by weight of the raw materials for preparing the soy sauce. The addition amount of the cellulase may be any value between 0.01% and 0.12% by weight of the raw materials for preparing the soy sauce, for example, 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.10%, 0.11% by weight.

Understandably, the cellulase can be added by any method conventional in the art, generally chosen to facilitate the manipulation of subsequent steps and to facilitate the application of the method. For example, the cellulase can be dissolved in water to prepare a solution for adding, and the prepared solution can be conveniently and uniformly sprayed to the raw material by means of a tool, so that the cellulase can uniformly and effectively act on the raw material.

In some embodiments, the cellulase is dissolved in water (25 ℃ C. To 35 ℃ C.) to produce a cellulase liquor. In the step (b), cellulase is added into the raw materials in a mode of cellulase liquid in the process of koji making. Further, the cellulase solution is uniformly sprayed on the surface of the raw material. Furthermore, the mass percentage concentration of the cellulase in the cellulase liquid is 1-4 per mill. Furthermore, the addition amount of the cellulase solution is 1 to 3 percent of the weight of the raw materials for preparing the soy sauce.

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

Understandably, the fermentation of the moromi to a pH of 6.30-6.50 means that the moromi pH is anywhere between 6.30-6.50, including, for example, 6.35, 6.4, 6.45.

In some embodiments, the neutral protease is added in an amount of 0.03 to 0.18 per mill of the weight of the moromi. Understandably, the addition amount of the neutral protease can be any value between 0.03 per thousand and 0.18 per thousand of the weight of the sauce mash, and also comprises 0.05 per thousand, 0.06 per thousand, 0.07 per thousand, 0.08 per thousand, 0.09 per thousand, 0.10 per thousand, 0.12 per thousand, 0.14 per thousand and 0.16 per thousand.

In some embodiments, the amylase is added in an amount of 0.01 to 0.12 per mill of the weight of the moromi. Understandably, the addition amount of amylase can be any value between 0.01 per thousand and 0.12 per thousand of the weight of the sauce mash, for example, 0.02 per thousand, 0.03 per thousand, 0.04 per thousand, 0.05 per thousand, 0.06 per thousand, 0.07 per thousand, 0.08 per thousand, 0.09 per thousand, 0.10 per thousand and 0.11 per thousand are also included.

Understandably, the manner of addition of the neutral protease and the amylase can be any method conventional in the art, and is generally selected to facilitate the handling of the subsequent steps and to be more advantageous for the present application. For example, the neutral protease and the amylase can be dissolved in water to prepare a solution for adding, and the prepared solution can be conveniently and uniformly sprayed to the sauce mash by means of a tool, so that the neutral protease and the amylase can be uniformly and effectively acted on the sauce mash.

In some embodiments, a mixed enzyme solution of neutral protease and amylase is prepared by dissolving neutral protease and amylase in water (25 ℃ C. To 35 ℃ C.). In the step (d), the neutral protease and the amylase are added to the raw materials in the form of a mixed enzyme solution of the neutral protease and the amylase. Further, the mixed enzyme solution of neutral protease and amylase is uniformly sprayed on the surface of the sauce mash. Further, the mass percentage concentration of the neutral protease in the mixed enzyme solution of the neutral protease and the amylase is 3-6%, and the mass percentage concentration of the amylase is 1-4%. Furthermore, the addition amount of the mixed enzyme liquid of the neutral protease and the amylase is 1 to 3 per mill of the weight of the soy sauce mash.

Understandably, the fermentation of the moromi to a pH of 5.10 to 5.50 means that the moromi pH is anywhere between 5.10 to 5.50, including, for example, 5.20, 5.30, 5.40.

In some embodiments, the acidic protease is added in an amount of 0.04 to 0.25 per mill of the weight of the moromi. Understandably, the addition amount of the acid protease can be any value between 0.04 per mill and 0.25 per mill of the weight of the sauce mash, for example, 0.05 per mill, 0.06 per mill, 0.07 per mill, 0.08 per mill, 0.09 per mill, 0.10 per mill, 0.12 per mill, 0.14 per mill, 0.16 per mill and 0.18 per mill are also included.

In some embodiments, the glutaminase enzyme is added in step (e) in an amount of 0.06 to 0.30 per thousand by weight of the moromi mash. Understandably, the addition amount of glutaminase can be any value between 0.06 per thousand and 0.30 per thousand of the weight of the sauce mash, for example, 0.07 per thousand, 0.08 per thousand, 0.09 per thousand, 0.10 per thousand, 0.12 per thousand, 0.14 per thousand, 0.16 per thousand, 0.18 per thousand, 0.20 per thousand, 0.22 per thousand, 0.24 per thousand, 0.26 per thousand and 0.28 per thousand are also included.

Understandably, the addition of the glutaminase and acid protease in step (e) may be by any method conventional in the art, and is generally selected to facilitate the operation of the subsequent steps and to be more advantageous for the present application. For example, the glutaminase and the acid protease can be dissolved in water to prepare a solution for adding, and the prepared solution can be conveniently and uniformly sprayed to soy sauce mash by means of a tool, so that the glutaminase and the acid protease can uniformly and effectively act on the soy sauce mash.

In some embodiments, a mixed enzyme solution of glutaminase and acidic protease is prepared by dissolving glutaminase and acidic protease in water (25 ℃ C. To 35 ℃ C.). In the 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 on the surface of the sauce mash. Furthermore, the mass percentage concentration of the glutaminase in the mixed enzyme solution of the glutaminase and the acid protease is 3-6 percent, and the mass percentage concentration of the acid protease is 2-5 percent. Furthermore, the addition amount of the mixed enzyme liquid of the glutaminase and the acid protease is 2 to 5 per mill of the weight of the soy sauce mash.

In some embodiments, the glutaminase enzyme is added in step (f) in an amount of 0.01 to 0.15 per thousand by weight of the moromi mash. Understandably, the adding amount of glutaminase can be any value between 0.01 per thousand and 0.15 per thousand of the weight of the sauce mash, for example, 0.02 per thousand, 0.04 per thousand, 0.06 per thousand, 0.08 per thousand, 0.10 per thousand, 0.12 per thousand and 0.14 per thousand are also included.

Understandably, the mode of addition of the glutaminase in step (f) may be any conventional method in the art, and is generally selected to facilitate the handling of the subsequent steps and to be more advantageous for the application. For example, glutaminase can be dissolved in water to form a solution for adding, and the solution can be conveniently and uniformly sprayed to the sauce mash by means of a tool, so that the glutaminase can uniformly and effectively act on the sauce mash.

In some embodiments, glutaminase is dissolved in water (25 ℃ C. To 35 ℃ C.) to prepare a glutaminase solution. In the step (f), glutaminase is added to the raw material in the form of glutaminase solution. Further, the glutaminase solution is uniformly sprayed on the surface of the soy sauce mash. Furthermore, the mass percentage concentration of the glutaminase in the glutaminase solution is 0.5-3%. Furthermore, the adding amount of the glutaminase solution is 2-5 per mill of the weight of the soy sauce mash.

Understandably, the process of solid-liquid separation of the mash may be carried out according to conventional procedures in the art, such as separation of soy sauce and soy sauce mash by plate and frame separation.

In still another aspect, the present application further provides a soy sauce produced by the production method according to any one of the above embodiments.

The following are specific examples. The present application is intended to be further described in detail to assist those skilled in the art and researchers to further understand the present application, and the relevant technical conditions and the like do not constitute any limitation to the present application. Any modification made within the scope of the claims of the present application is within the scope of the claims of the present application. The examples, which are not specifically illustrated, employ drugs and equipment, all of which are conventional in the art. The experimental procedures without specifying the specific conditions in the examples were carried out under the conventional conditions such as those described in the literature, in books, or as recommended by the manufacturer.

Unless otherwise specified, the raw materials and reagents used in the following examples are all commercially available products or can be prepared by known methods. The experimental procedures, in which specific conditions are not indicated in the examples, were carried out according to conventional conditions, such as those described in the literature, in books, or as recommended by the manufacturer.

Hereinafter, "moistening" means adding an appropriate amount of moisture to the raw material and allowing the raw material to uniformly absorb the moisture. "moisture ratio" refers to the weight of the soybeans and the weight of water used in the moisture operation.

Example 1

1. Pretreatment of soybeans: screening soybeans, removing impurities, moistening with water (the moistening ratio is 125%), and steaming at 120 deg.C under 0.18MPa for 90s.

2. Pretreatment of wheat: screening and removing impurities from wheat, baking at 250 deg.C for 2min, cooling to 40 deg.C, and grinding.

3. Preparing yeast: uniformly mixing the soybeans pretreated in the step 1-2 with wheat flour to obtain a raw material, adding 0.1% (m/m) of aspergillus oryzae according to the weight of the raw material, and uniformly stirring and making yeast.

4. Preparation of enzyme solution A: and (3) dissolving cellulase into tap water at 30 ℃ to obtain an enzyme solution A, wherein the mass percentage concentration of the cellulase is 3 per mill.

5. Adding enzyme solution A: and (5) adding the enzyme solution A obtained in the step (4) into the yeast material by spraying after the yeast is prepared in the step (3) for 25 hours, wherein the adding proportion is 2% of the weight of the raw material, and continuously culturing for 20 hours to obtain the mature yeast material.

6. Preparing mash: adding 2.0 times of salt water into the yeast material obtained in the step 5 according to the weight, and making mash. The concentration of the used salt solution is 20%, and the pH value of the soy sauce mash is 6.45.

7. Preparing an enzyme solution B: dissolving neutral protease and amylase into tap water at 30 ℃ to obtain an enzyme solution B, wherein the mass percentage concentrations of the neutral protease and the amylase are respectively 4% and 2%.

8. Adding an enzyme solution B: adding the enzyme solution B obtained in the step 7 into the sauce mash prepared in the step 6, wherein the adding proportion is 2 per mill of the weight of the sauce mash obtained in the step 6, stirring for 45min, and then carrying out sauce mash fermentation.

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

10. Adding enzyme solution C: and (3) after the step 8 is finished, fermenting for 8 days, wherein the pH value of the sauce mash is 5.40, adding the enzyme solution C obtained in the step 9 into the sauce mash, adding 3 per mill of the weight of the sauce mash obtained in the step 6, stirring for 45min, and continuing to ferment.

11. Preparation of enzyme solution D: and (3) dissolving glutaminase into tap water at the temperature of 30 ℃ to obtain enzyme liquid D, wherein the mass percentage concentration of the glutaminase is 2%.

12. Adding an enzyme solution D: and (3) continuing to ferment for 40 days after the step 10 is finished, wherein the pH value of the sauce mash is 4.95, adding the enzyme solution D obtained in the step 11 into the sauce mash, wherein the adding proportion is 3 per mill of the weight of the sauce mash obtained in the step 6, stirring for 45min, continuing to ferment, and fermenting for 65 days to obtain mature sauce mash.

13. Squeezing: separating the soy sauce mash fermented and matured in the step 12 from soy sauce mash by a plate frame.

Example 2

The preparation method is basically the same as that of example 1, except that:

the adding proportion of the enzyme solution A is 1.5 percent of the weight of the raw materials;

the adding proportion of the enzyme solution B is 1.5 per mill of the weight of the soy sauce mash;

the adding proportion of the enzyme solution C is 2.5 per mill of the weight of the sauce mash;

the adding proportion of the enzyme solution D is 1 per mill of the weight of the soy sauce mash.

Example 3

The preparation method is basically the same as that of example 1, except that:

the adding proportion of the enzyme solution A is 3 percent of the weight of the raw materials;

the adding proportion of the enzyme solution B is 3 per mill of the weight of the sauce mash;

the adding proportion of the enzyme solution C is 5 per mill of the weight of the sauce mash;

the adding proportion of the enzyme solution D is 3 per mill of the weight of the sauce mash.

Example 4

The preparation method is basically the same as that of example 1, except that:

the adding proportion of the enzyme solution A is 4 percent of the weight of the raw materials;

the adding proportion of the enzyme solution B is 4 per mill of the weight of the soy sauce mash;

the adding proportion of the enzyme solution C is 6 per mill of the weight of the sauce mash;

the adding proportion of the enzyme solution D is 4 per mill of the weight of the soy sauce mash.

Comparative example 1

4. Preparing mash: adding 2.0 times of salt water into the yeast material obtained in the step 3 according to the weight, and making mash, wherein the salt water concentration used for making the mash is 20%, and the pH value of the sauce mash is 6.88.

5. Fermentation: and 4, stirring the sauce mash obtained by mash preparation in the step 4 for 45min every 10d, and fermenting for 65d to obtain mature sauce mash.

6. Squeezing: and (5) separating the soy sauce mash fermented in the step (5) from soy sauce mash by a plate frame.

Comparative example 2

3. Preparing yeast: uniformly mixing the soybean and the wheat flour pretreated in the step 1-2 to obtain a raw material, adding 0.1% (m/m) of aspergillus oryzae according to the weight of the raw material, and uniformly stirring and making yeast.

4. Preparing mash: adding 2.0 times of salt water into the yeast material obtained in the step 3 according to the weight, and making mash. The concentration of the used salt solution is 20%, and the pH value of the soy sauce mash is 6.45.

5. Preparation of enzyme solution A: and (3) dissolving cellulase into tap water at 30 ℃ to obtain an enzyme solution A, wherein the mass percentage concentration of the cellulase is 3 per mill.

Preparing an enzyme solution B: dissolving neutral protease and amylase into tap water at 30 ℃ to obtain an enzyme solution B, wherein the mass percentage concentrations of the neutral protease and the amylase are respectively 4% and 2%.

Preparation of enzyme solution C: and (2) dissolving glutaminase and acid protease in tap water at 30 ℃ to obtain enzyme solution C, wherein the mass percentage concentrations of the glutaminase and the acid protease are respectively 4% and 3%.

Preparation of enzyme solution D: and (3) dissolving glutaminase into tap water at the temperature of 30 ℃ to obtain enzyme liquid D, wherein the mass percentage concentration of the glutaminase is 2%.

6. Adding enzyme liquid for fermentation: simultaneously adding the enzyme solutions A-D prepared in the step 5 into the sauce mash obtained in the step 4, wherein the adding proportion of the enzyme solution A is 2% of the weight of the raw materials; the adding proportion of the enzyme liquid B is 2 per mill of the weight of the sauce mash obtained by the mash preparation in the step 4; the adding proportion of the enzyme solution C is 3 per mill of the weight of the sauce mash obtained by the mash preparation in the step 4; and (4) adding the enzyme solution D in a proportion of 3 per mill of the weight of the sauce mash obtained in the step (4), stirring for 45min, continuing fermenting the sauce mash, and fermenting for 65D to obtain the mature sauce mash.

7. Squeezing: and (4) separating the soy sauce mash fermented in the step (6) from soy sauce mash by a plate frame.

Comparative example 3

1. Pretreatment of soybeans: screening soybeans, removing impurities, moistening with water (the moistening ratio is 125%), and then cooking under the conditions of 120 ℃ and 0.18MPa for 90s.

4. Preparation of enzyme solution D: and (3) dissolving glutaminase into tap water at the temperature of 30 ℃ to obtain enzyme liquid D, wherein the mass percentage concentration of the glutaminase is 2%.

5. Adding enzyme solution D: and (4) spraying the enzyme solution D obtained in the step (4) after the starter propagation in the step (3) for 25h, adding the enzyme solution D into the starter material according to the addition proportion of 2% of the weight of the raw materials, and continuously culturing for 20h to obtain the mature starter material.

8. Adding enzyme solution B: adding the enzyme solution B obtained in the step 7 into the sauce mash prepared in the step 6, wherein the adding proportion is 2 per mill of the weight of the sauce mash obtained in the step 6, stirring for 45min, and then carrying out sauce mash fermentation.

9. Preparation of enzyme solution C: and (2) dissolving glutaminase and acid protease in tap water at 30 ℃ to obtain enzyme solution C, wherein the mass percentage concentrations of the glutaminase and the acid protease are respectively 4% and 3%.

10. Adding enzyme solution C: and (5) after the step 8 is finished, fermenting for 8 days, wherein the pH value of the sauce mash is 5.40, adding the enzyme solution C obtained in the step 9 into the sauce mash, adding 3 per mill of the weight of the sauce mash obtained in the step 6, stirring for 45min, and continuing to ferment.

11. Preparation of enzyme solution A: and (3) dissolving cellulase into tap water at 30 ℃ to obtain an enzyme solution A, wherein the mass percentage concentration of the cellulase is 3 per mill.

12. Adding an enzyme solution A: and (3) continuing to ferment for 40 days after the step 10 is finished, wherein the pH value of the sauce mash is 4.95, adding the enzyme solution A obtained in the step 11 into the sauce mash, wherein the adding proportion is 3 per mill of the weight of the sauce mash obtained in the step 6, stirring for 45min, continuing to ferment, and fermenting for 65 days to obtain mature sauce mash.

13. Squeezing: and (4) separating the soy sauce mash fermented in the step (12) from soy sauce mash by a plate frame.

Comparative example 4

The preparation method is basically the same as that of example 1, except that step 4 and step 5 are omitted, that is, enzyme solution A is not added, and the yeast material obtained in step 3 is directly added with 2.0 times of salt solution by weight to prepare mash.

Comparative example 5

The preparation method is basically the same as that of example 1, except that steps 11 and 12 are omitted, namely, the moromi mash of step 10 is directly fermented to 65 days without adding the enzyme solution D to obtain mature moromi mash, and then soy sauce and moromi mash are separated by a plate frame.

The soy sauce prepared in examples 1 to 4 and comparative examples 1 to 5 were examined, and the examination items and examination methods and standards were as follows:

1. yield per unit of total nitrogen glutamic acid: the unit total nitrogen glutamic acid yield = crude oil glutamic acid/crude oil total nitrogen, wherein the crude oil total nitrogen is determined by Kjeldahl method according to GB 5009.5-2016 detection of protein in food safety national standard food; the crude glutamic acid is detected according to a glutamic acid detection kit.

2. Residue protein: the residue protein is determined by Kjeldahl method according to the first method of GB 5009.5-2016 detection of protein in food safety national standard food.

The conditions and test results for preparing soy sauce in examples 1 to 4 and comparative examples 1 to 5 are shown in Table 1 below:

TABLE 1

Item	Order of enzyme solution addition	Enzyme solution A/B/C/D addition ratio	Yield per unit of total nitrogen glutamic acid	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	Without addition	/	0.61	7.0
Comparative example 2	Enzyme solution is mixed and added	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

As can be seen from Table 1, the yields of total nitrogen glutamic acid per unit in examples 1 to 4 of the present application are significantly better than those in comparative examples 1 to 5.

Compared with the comparative example 1 and the comparative example 2, the addition amount of the enzyme solution is consistent, the yield of the unit per-nitrogen glutamic acid in the example 1 is obviously higher than that in the comparative example 2, compared with the comparative example 1 and the comparative example 3, the yield of the unit per-nitrogen glutamic acid in the example 1 is obviously higher than that in the comparative example 3, and the conditions that the activity of the enzyme system needs to be enhanced in different stages in the starter propagation fermentation process are pointed.

Comparing example 1 with comparative examples 4 to 5, the yield per unit of the total nitrogen glutamic acid in example 1 is also significantly higher than that in comparative examples 4 to 5, and although the yield per unit of the total nitrogen glutamic acid in comparative examples 4 to 5 is improved compared with that in comparative examples, the yield per unit of the total nitrogen glutamic acid is still lower compared with that in example 1, which shows that the enzyme activity is influenced in the absence of the enhancing effect of any one of the enzymes.

In conclusion, the preparation method of the soy sauce provided by the application can be used for brewing the soy sauce efficiently and economically, and the yield of unit total nitrogen glutamic acid is obviously improved.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present application, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the concept of the present application, which falls within the scope of protection of the present application. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims

1. The preparation method of the soy sauce is characterized by comprising the following steps:

(a) Providing raw materials for preparing soy sauce;

(c) Adding salt water into the finished koji to prepare fermented glutinous rice to obtain fermented glutinous rice and fermenting the fermented glutinous rice;

(d) When the pH value of the sauce mash reaches 6.30-6.50, adding neutral protease and amylase into the sauce mash and continuing fermentation;

(e) 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;

(f) 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;

2. The method for preparing soy sauce according to claim 1, wherein the raw material comprises one or more of soybean, wheat, bran, peanut, broad bean, pea, corn, rice and millet.

3. The method for preparing soy sauce according to claim 1, wherein the Aspergillus comprises one or more of Aspergillus oryzae, aspergillus niger and Aspergillus sojae.

4. The method for producing soy sauce according to claim 1, wherein in the step of adding cellulase during koji-making, the cellulase is added at a time of koji-making for 24 to 30 hours.

5. The method for producing soy sauce according to claim 1 or 4, wherein the cellulase is added in an amount of 0.01 to 0.12% by weight based on the weight of the raw materials for producing soy sauce.

6. The method for producing soy sauce according to claim 1, wherein the amount of the saline solution added is 1.5 to 2.0 times the weight of the koji, and the concentration of the saline solution is 18 to 25% by mass.

7. The method for preparing soy sauce according to claim 1, wherein step (d) satisfies at least one of the following conditions:

8. The method for preparing soy sauce according to claim 1, wherein step (e) satisfies at least one of the following conditions:

9. The method for preparing soy sauce according to claim 1, wherein glutaminase is added in an amount of 0.01 to 0.15% by weight of the soy sauce mash in the step (f).

10. A soy sauce produced by the method for producing a soy sauce according to any one of claims 1 to 9.