A method for preparing low-salt fermented sauce

Abstract

The present invention relates to the technical field of condiment production, and specifically discloses a method for preparing a low-salt fermented sauce. The present invention breaks through the fermentation method of traditional sauces and provides an efficient method for preparing a low-salt fermented sauce. The process adopts the core process of "enzymatic hydrolysis-fermentation-heat treatment", and the preparation process is a salt-free system, which is simple to operate and has high raw material utilization efficiency. The fermentation process only takes about 7 days. The obtained low-salt sauce product has a strong aroma, and the overall product has moderate viscosity. It is brighter reddish brown, bright and shiny, with a strong sauce aroma, rich and mellow taste, and its flavor quality is guaranteed while meeting the low-salt requirements. The preparation method does not require high-cost equipment, has high production efficiency, low production cost, can be easily adapted to production needs of different scales, and has broad market application prospects.

Description

Technical Field

[0001] The invention belongs to the technical field of condiment production, and in particular relates to a method for preparing a low-salt fermented seasoning sauce. Background Art

[0002] More and more research data indicate that high salt intake is one of the important causes of hypertension and cardiovascular and cerebrovascular diseases. As people's living standards improve, food safety, nutrition, health and flavor have gradually become key factors for consumers to choose to buy. As an important ingredient to improve the flavor of food, condiments are indispensable in modern life. As low-salt diets are favored by more and more consumers, low-salt condiments are an inevitable trend for product upgrading.

[0003] Fermented sauces are condiments that use a complex enzyme system produced by microorganisms to convert nutrients such as protein and starch in raw materials into flavoring substances such as polypeptides, amino acids, sugars and aroma compounds to obtain unique flavors. In the preparation process of traditional fermented sauces (such as soy sauce and fish sauce), in order to inhibit the growth and reproduction of most food-borne spoilage bacteria, a high-salt fermentation system is often used, which has a great inhibitory effect on the growth and reproduction of enzymes and fermentation microorganisms contained in the system, resulting in a production cycle of 2-6 months, high production costs, and the salt content of the product is usually above 10%. Existing low-salt fermentation processes are often easily affected by miscellaneous bacteria, and there are problems such as difficulty in regulating the fermentation process, difficulty in regulating product quality, and bland taste, which makes it difficult to meet the needs of the modern market.

[0004] At present, some low-salt sauces on the market are obtained by directly diluting the sauce obtained by high-salt fermentation with water to reduce the salt content. Although this method is easy to operate and has low production costs, it often reduces the flavor quality of the product and is difficult to meet consumers' demand for high-quality healthy condiments. Patent CN102246947B discloses a low-salt soy sauce and a preparation method thereof. The soy sauce is first prepared by a 18% high-salt fermentation process, and then desalination is carried out by electrodialysis. The salt content of the produced soy sauce is nearly half of that of ordinary commercial soy sauce. It has a strong ester flavor and sauce flavor, no other bad odors, a delicious and mellow taste, and a clear body; however, this method requires advanced production equipment and a complex production process, and the production cost is high, which is not suitable for large-scale production. Patent CN104642998A discloses a rapid brewing method for low-salt fish sauce by alkaline method, which promotes the rapid decomposition of fish protein by adding alkaline water, thereby realizing low-salt rapid fermentation of fish sauce, but the added alkaline water is a non-natural additive, which does not meet the trend of modern clean labels or green production. Patent CN116602391B discloses a method for preparing a low-salt bean paste seasoning, which uses enzymatic hydrolysis combined with yeast fermentation to increase the flavor of the low-salt bean paste, thereby obtaining a low-salt bean paste with a short fermentation time and a mellow flavor. However, this technical solution is used to prepare a semi-solid sauce, and its fermentation system has a high solid content and a low water content, and has a relatively strong antiseptic ability, and is not suitable for a liquid fermentation system with a high water activity. Summary of the invention

[0005] The purpose of the present invention is to overcome the above-mentioned problems existing in the prior art and to provide a method for preparing a low-salt fermented sauce. A low-salt flavored sauce is obtained through a composite enzymatic hydrolysis, fermentation and heat treatment process. The preparation process is a salt-free system, which greatly shortens the fermentation cycle. The production process is simple to operate, the raw material utilization efficiency is high, and no high-cost equipment is required, which reduces the production cost. The obtained low-salt sauce product has a strong aroma. The overall product has good sensory characteristics such as richness, fullness, long aftertaste, and strong caramel aroma, and has a high market application value.

[0006] To achieve the above objectives, the inventors conducted in-depth research and completed the solution of the present invention after repeated research and demonstration, which is as follows:

[0007] In a first aspect, the present invention provides a method for preparing a low-salt fermented sauce, the method comprising the following steps:

[0008] 1) mixing steamed soybeans with fried wheat, inoculating Aspergillus oryzae for mixed culture to obtain finished koji;

[0009] 2) Mixing the koji, steamed and cooked soybeans with water to prepare the prepared soybean koji, and adding a composite protease to perform enzymolysis to obtain an enzymolysis solution;

[0010] 3) The enzymatic solution is inactivated, cooled, filtered, and then the enzymatic supernatant is obtained. Lactobacillus plantarum and active dry yeast are added, mixed, and fermented at 28-32° C. The inoculation amounts of Lactobacillus plantarum and active dry yeast are 10 4 -10 6 CFU / g, 10 3 -10 5 CFU / g;

[0011] 4) The fermented enzymatic hydrolysate is subjected to heat treatment to obtain a low-salt fermented sauce;

[0012] In the enzymatic hydrolysis process of step 2), 1% (w / w) cellulase was first added to soybean koji for hydrolysis at 55°C for 3 hours, and then 0.5% (w / w) neutral protease and 0.8% (w / w) flavor protease were added to continue the hydrolysis for 3 hours, and finally 0.4% (w / w) medium-temperature α-amylase was added for hydrolysis at 60°C for 3 hours.

[0013] In some embodiments, the fermentation time in step 3) is 44-52 hours.

[0014] In some embodiments, in step 2), the mixing ratio of koji, steamed soybeans and water is 1:1:3 (w / w).

[0015] In some embodiments, in step 1), the mixing ratio of the steamed soybeans and the fried wheat is 9:1 (w / w).

[0016] In some embodiments, the moisture content of the roasted wheat in step 1) is below 10%.

[0017] In some embodiments, the heat treatment time in step 4) is 7-9 hours.

[0018] In some embodiments, the heat treatment temperature in step 4) is 75-90°C, preferably 85-90°C.

[0019] In a second aspect, the present invention provides a low-salt fermented sauce, which is prepared by the preparation method of the present invention.

[0020] In a third aspect, the present invention provides a sauce, which comprises the low-salt fermented sauce according to claim 9 and can be obtained by adding and blending other auxiliary materials (such as sugar, monosodium glutamate, spices, etc.) as required.

[0021] One or more technical solutions provided in the embodiments of the present application have at least the following technical effects or advantages:

[0022] 1. The present invention breaks through the traditional fermentation method of sauces and provides an efficient method for preparing low-salt fermented sauces. The process adopts the core process of "enzymatic hydrolysis-fermentation-heat treatment". The preparation process is a salt-free system, the operation is simple, the raw material utilization efficiency is high, the fermentation process only takes about 7 days, no high-cost equipment is required, the production efficiency is high, and the production cost is low. Whether it is a large-scale production enterprise or a small-scale workshop, the method can be easily applied for production, and it has broad market application prospects.

[0023] 2. The method for preparing a low-salt fermented sauce provided by the present invention has a strong aroma, moderate viscosity of the overall product, a brighter reddish-brown color, bright and shiny color, a strong sauce aroma, and a rich and mellow taste. It meets the low-salt requirement while ensuring its flavor quality, and is in line with consumer demand.

[0024] 3. The preparation method of the low-salt fermented sauce provided by the present invention adopts a salt-free system in the preparation process. On the one hand, it reduces the requirements on the strains needed for fermentation, and on the other hand, it eliminates the inhibitory effect of salt on enzymes and fermentation microorganisms, which is conducive to the rapid proliferation of fermentation microorganisms such as Lactobacillus plantarum and active dry yeast, accelerates the enzymatic hydrolysis and fermentation process, greatly shortens the fermentation time, improves the flavor and quality of the sauce, reduces production costs, and improves product quality.

[0025] 4. The preparation method of the low-salt fermented sauce provided by the present invention adopts efficient step-by-step enzymolysis technology to effectively avoid mutual interference between different enzymes, ensure that each enzyme can exert the maximum catalytic efficiency under the most suitable conditions, and quickly hydrolyze the nutrients such as protein and starch in the raw soybeans and wheat into small molecular amino acids and reducing sugars. The first step is to use the hydrolysis of cellulose to hydrolyze the cellulose substances in the bean koji and soybean raw materials into small molecular sugars; increase the content of soluble solids in the solution, which is conducive to the action of the subsequent enzymes; the second step is to use protease to preferentially decompose macromolecular proteins; the third step is to further hydrolyze starch substances with amylase, further improve the utilization rate of product raw materials, and improve the efficiency of enzymolysis. This process greatly improves the utilization efficiency of raw materials and enables more nutrients to be released and utilized. Through enzymolysis, not only a rich nutrient basis is provided for the subsequent fermentation process, the fermentation process is accelerated, but also the regulation of the fermentation process becomes easier to control, reducing the uncertainty of natural microbial fermentation.

[0026] 5. The preparation method of low-salt fermented sauce provided by the present invention is to co-inoculate plant lactobacillus and active dry yeast in the enzymatic hydrolyzate for cooperative fermentation. On the one hand, the metabolic activity of plant lactobacillus produces lactic acid and organic acid, quickly reduces the pH value, limits the growth of harmful spoilage bacteria, and maintains the stability and safety of the product without relying on high salt concentration; active dry yeast provides growth-promoting factors for lactic acid bacteria during the fermentation process and also prevents excessive lactic acid production. The acidic environment created by lactic acid bacteria is conducive to the growth and metabolism of active dry yeast, and stimulates yeast to produce more flavor metabolites. On the other hand, cooperative fermentation improves the total nitrogen conversion rate of raw materials, significantly increases the total amount of free amino acids in the fermentation liquid, especially the content of umami amino acids and sweet amino acids, which are increased by 28.18% and 85.22% respectively compared with non-inoculation, which is conducive to the production of richer umami and sweet taste, and does not significantly increase the generation of bitter amino acids. In addition, compared with other leavening agents, plant lactobacillus can increase the types of volatile flavor substances, especially the increase of alcohol ester substances, which is conducive to the formation of ester-flavored fruit juice fruity aroma and floral aroma; active dry yeast helps to form a unique sweet and sour flavor and fresh aroma. Therefore, the technical scheme uses the synergistic fermentation of Lactobacillus plantarum and active dry yeast, which can improve the sweetness and richness of the sauce, greatly enrich the flavor layers of the sauce, make its taste mellower, and significantly improve the flavor characteristics and sensory quality of the fermented juice, thereby jointly creating a high-quality fermented juice product and providing consumers with a low-salt sauce with a unique taste and rich flavor. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 The changes of various physical and chemical indicators during enzymatic hydrolysis;

[0028] Figure 2 The colony counts of different strains during fermentation;

[0029] Figure 3 To investigate the changes in various physical and chemical indicators of sauces fermented by different strains;

[0030] Figure 4 The results of flavor evaluation of sauces fermented by different strains of bacteria;

[0031] Figure 5 The changes of various physical and chemical indicators of sauces after different heat treatments;

[0032] Figure 6 The results of flavor evaluation of fermented sauces after different heat treatments;

[0033] Figure 7 Flavor evaluation results of low-salt fermented sauce and commercial low-salt sauce. DETAILED DESCRIPTION

[0034] In order to facilitate the understanding of the present invention, the present invention will be described more fully below. However, the present invention can be implemented 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 present invention more thorough and comprehensive.

[0035] 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 invention belongs.

[0036] Unless otherwise specified, the reagents, methods and equipment used in the present invention are conventional food-grade reagents, methods and equipment in the art.

[0037] The terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more of the associated listed items.

[0038] Example 1 Enzymatic Hydrolysis Process Test

[0039] (1) Koji making:

[0040] First, soak the washed soybeans and tap water at a ratio of 1:3 (w / v) at room temperature for 15-18h. The soaked soybeans are steamed in a pressure cooker for about 45min and then cooled for use. The wheat is stir-fried at about 170-180℃ for 5-10min until the wheat presents a light brown color and a unique wheat aroma, and the moisture content of the wheat after stir-frying is controlled below 10%. When the temperature of the steamed soybeans and stir-fried wheat is cooled to about 40℃, the steamed soybeans and stir-fried wheat are mixed in a ratio of 9:1 (w / w) for use. Inoculate Aspergillus oryzae (Shanghai Brewing 3.042) in an amount of 0.8% of the mass ratio after mixing, stir well, mix evenly, and make koji in a koji-making room at 32-37℃ for 35-40h, and the soybean koji is light yellow or golden yellow, with a strong bean aroma and a unique aroma of fermentation, and no odor to complete the koji making.

[0041] (2) Enzymatic hydrolysis:

[0042] After the koji making is completed, the soybean koji, steamed soybeans and sterilized water are fully mixed in a ratio of 1:1:3 (w / w), added to a constant temperature shaking water bath at an appropriate temperature, and after the temperature reaches the set value and the reading is stable, various enzyme preparations are added step by step as shown in Table 1, and the enzymatic hydrolysis conditions are controlled to prepare the enzymatic sauce mash.

[0043] (3) Enzymatic hydrolysis effect detection:

[0044] The enzymatic hydrolysate after 0, 3, 6, and 9 hours of enzymatic hydrolysis was filtered through gauze and centrifuged for physical and chemical index testing. The test results were recorded in Figure 1 middle.

[0045] Table 1: Enzymatic hydrolysis experimental conditions

[0046]

[0047] Figure 1 The results showed that as the enzymatic hydrolysis time progressed, the pH of the hydrolyzate gradually decreased, while the contents of soluble solids, total acid, amino acid nitrogen, total nitrogen and reducing sugars all increased significantly, indicating that the large molecular proteins, large molecular starches and cellulose in the raw materials were broken down into small molecular peptides and amino acids, reducing sugars and organic acids by endogenous and exogenously added enzymes in the bean koji during the enzymatic hydrolysis process.

[0048] Soybean koji contains rich endogenous enzymes, such as protease, amylase and cellulase. After being combined with soybeans, these endogenous enzymes can fully play their role, reduce the addition of exogenous enzymes, improve the efficiency of enzymatic hydrolysis and reduce costs. Step-by-step enzymatic hydrolysis effectively avoids mutual interference between different enzymes, ensuring that each enzyme can exert its maximum catalytic efficiency under the most suitable conditions. The appropriate enzymatic hydrolysis time will neither cause incomplete enzymatic hydrolysis due to being too short, nor produce unnecessary by-products or reduce product quality due to being too long, thereby obtaining high-quality enzymatic hydrolysis products. The efficient enzymatic hydrolysis effect improves the utilization efficiency of raw materials and allows more nutrients to be released and utilized. It can not only provide a rich nutrient basis for the subsequent fermentation process and accelerate the fermentation process, but also make the regulation of the fermentation process easier to control and reduce the uncertainty of natural microbial fermentation.

[0049] Example 2 Yeast and lactic acid bacteria synergistic fermentation test

[0050] (1) The enzymatic hydrolysis mash was prepared according to the method described in Example 1. The enzymatic hydrolysis liquid container after 9 hours of enzymatic hydrolysis was placed in a constant temperature water bath at 85° C. for 20 minutes to inactivate the enzyme. After cooling to room temperature, the supernatant was separated from the enzymatic hydrolysis residue by centrifugal filtration to obtain the enzymatic hydrolysis supernatant.

[0051] (2) Adjust the concentration of activated Lactobacillus plantarum and active dry yeast to 10 6 -10 7 CFU / g, 10 5 -10 6 CFU / g, and then mixed evenly at a ratio of 1:1 (w / w), inoculated into the enzymatic supernatant after enzyme inactivation at an inoculum of 5% (w / w), and placed in a constant temperature shaker at 30-32°C for 150-180rpm for 48h to obtain a fermentation liquid. At the same time, a control group without added strains (control group), a group with only added active dry yeast (yeast group), and a group with only added Lactobacillus plantarum (lactic acid bacteria group) were set for comparative analysis.

[0052] (3) After fermentation for 48 hours, the fermented liquid is placed in a magnetic stirring water bath for stirring and heating treatment at 85°C for 7 hours. The fermented liquid is cooled to room temperature, and about 5-6% (w / w) salt is weighed into the fermented liquid and stirred to obtain a low-salt fermented sauce.

[0053] (4) At 0 h, 24 h and 48 h of fermentation, samples from different fermentation groups were taken for fermentation colony count, physical and chemical indexes and free amino acid detection, and the results were recorded in Figure 2 , Figure 3 And Table 2.

[0054] (5) 15 evaluators with rich experience in seasoning evaluation were invited to conduct sensory evaluation on the five dimensions of color, aroma, body, richness and umami of the fermented seasoning. The samples were scored based on the evaluation criteria in Table 3 and the average value was taken. The sample scores and the final sensory evaluation results were recorded in Tables 4 and Figure 4 middle.

[0055] Table 2 Free amino acid content before and after fermentation under different inoculation methods (g / 100g)

[0056]

[0057] Table 3 Sensory scoring standards for low-salt fermented sauce products

[0058]

[0059]

[0060] Table 4 Sensory evaluation scores of sauces fermented by different strains

[0061]

[0062] like Figure 2 As shown, the total colony count of the fermentation samples inoculated with single active dry yeast or single Lactobacillus plantarum, as well as the combined inoculation, showed a trend of gradually increasing with the extension of fermentation time, indicating that the soybean hydrolysate is rich in nutrients and contains nitrogen and carbon sources required for microbial growth and metabolism.

[0063] like Figure 3As shown in the figure, the simultaneous inoculation of Lactobacillus plantarum and active dry yeast produced a good synergistic fermentation effect. On the one hand, Lactobacillus plantarum can produce a large amount of lactic acid and organic acid through its own growth and metabolism, thereby quickly reducing the pH value of the system. This effect not only effectively limits the growth of other harmful spoilage bacteria and creates a relatively safe environment for the fermentation of the sauce, but also this acidic environment is very conducive to the growth and metabolism of active dry yeast. Under this condition, active dry yeast can produce more flavor metabolites, thereby forming a better flavor; at the same time, active dry yeast has both a promoting and an antagonistic effect on Lactobacillus plantarum, which prevents excessive lactic acid content while producing lactic acid, avoiding excessive acidity that makes the sauce sour and reduces the quality of the sauce. On the other hand, the combined inoculation group is also more prominent in the formation of total nitrogen and amino acid nitrogen, which indicates that combined fermentation is more efficient in the conversion of total nitrogen.

[0064] Free amino acids contribute to the taste sensations of umami, sweetness, and sourness in the crude soy sauce, and are one of the important substances that present the unique flavor of soy sauce. As can be seen from Table 2, the addition of Lactobacillus plantarum has a positive effect on the production of amino acids that present umami, while the addition of active dry yeast has a positive effect on the formation of amino acids with sweet effects. The combined inoculation of the two strains significantly increased the total amount of free amino acids in the fermentation broth, especially the content of umami amino acids and sweet amino acids, which increased by 21.30-36.46% and 7.55-85.22% respectively compared with the other three groups. Figure 3 The results of reducing sugar in the medium indicate that the combined fermentation of Lactobacillus plantarum and active dry yeast is conducive to producing richer umami and sweet taste, and does not significantly increase the production of bitter amino acids, which will have a positive effect on the flavor effect of the fermentation liquid.

[0065] Table 4 and Figure 4 The results showed that the flavor of low-salt fermented sauces obtained by fermentation with different strains was better than that of the control group, especially the combined group, whose richness and umami scores were significantly higher than those of the yeast group and lactic acid bacteria group, and its body and aroma were not reduced. The above results show that Lactobacillus plantarum combined with active dry yeast fermentation can improve the umami and richness of the sauce, and ensure the quality of the product without affecting the color, aroma and body, providing a rich taste.

[0066] In summary, the synergistic effect of active dry yeast and Lactobacillus plantarum is crucial in the preparation of low-salt fermented sauces. Lactobacillus plantarum creates a safe fermentation environment by lowering the pH value and promotes the production of flavor substances by yeast. At the same time, the hydrolysis of proteins and peptides by the enzyme system in Lactobacillus plantarum and active dry yeast strains and the efficient conversion of total nitrogen jointly promote the improvement of the quality of the sauce. The synergistic fermentation of active dry yeast and Lactobacillus plantarum can greatly enrich the flavor level of the sauce and make it taste mellower. This fermentation method can not only improve the nutritional value of the sauce and provide consumers with a low-salt sauce with a unique taste and rich flavor, but also has significant advantages in improving production efficiency and reducing costs, and has broad market application prospects.

[0067] Example 3 Heat treatment process test

[0068] The lactic acid bacteria and yeast combined fermentation liquid was prepared according to the method described in Example 2, and the fermentation liquid was placed in a magnetic stirring water bath for stirring and heating treatment. Two heating temperatures were set, namely a lower temperature (low temperature group: 75-80°C) and a higher temperature (high temperature group: 85-90°C). The heat treatment time was 7h. The physical and chemical indicators of the fermentation liquid were measured by sampling during the treatment process, and the results were recorded in Figure 5 And Table 5.

[0069] The fermented liquid after heat treatment was cooled to room temperature, and about 5-6% (w / w) salt was weighed into the fermented liquid, and stirred evenly to obtain a low-salt fermented sauce. Fifteen evaluators with rich experience in seasoning evaluation were invited to conduct sensory evaluation on the five dimensions of color, aroma, body, richness and umami of the fermented sauces (low temperature group and high temperature group) with different heat treatments according to the method described in Example 2. At the same time, the fermented sauces before heat reaction were compared. The evaluation results are recorded in Tables 6 and 7. Figure 6 middle.

[0070] Table 5 Free amino acid content under different heat treatment conditions (g / 100g)

[0071]

[0072]

[0073] Table 6 Sensory evaluation scores of fermented sauces under different thermal reaction conditions

[0074]

[0075] like Figure 5As shown in the figure, during the high-temperature heat treatment, reducing sugars and amino acids decreased more significantly, probably because the Maillard reaction involved was more intense; more total acid was generated in this group of samples, and the pH dropped more significantly. The changes in these substances related to sensory flavor are crucial to the final flavor formation of the fermented juice after heat treatment.

[0076] As shown in Table 5, the total free amino acid content of the samples treated with low temperature and high temperature groups decreased by 20.70% and 37.01% respectively compared with that before heat treatment. Among them, the groups with the largest decrease were the bitter amino acid groups, with a decrease of 23.78% and 44.04% in the low temperature and high temperature groups respectively; the group with the smallest decrease was the umami amino acid group, with a decrease of 21.46% and 30.53%. Temperature directly affects the progress of the Maillard reaction, and high temperature is conducive to increasing the consumption of amino acids, reducing the content of bitter amino acids, promoting the progress of the Maillard reaction, and thus affecting the final flavor of the sauce. Although high temperature also reduces the umami and sweet amino acids in the sauce, bitterness is more easily perceived in sensory evaluation. In short, the thermal reaction is beneficial to the flavor of the sauce.

[0077] Table 6 and Figure 6 The results showed that the flavor of the low-salt fermented sauce after heat treatment at different temperatures was better than that of the control group, especially the high temperature group, whose color, aroma, and richness scores were significantly higher than those of the control group and the low temperature group, and its body and umami taste were not reduced.

[0078] Example 4 Sensory Evaluation

[0079] The low-salt fermented sauce from the high temperature group in Example 3 was used for flavor evaluation compared with two commercially available low-salt sauces.

[0080] Fifteen judges with rich experience in seasoning evaluation were invited to conduct sensory evaluation on the five dimensions of color, aroma, body, richness and umami of different fermented seasonings. The samples were scored and the average value was taken. The sample scores and final sensory evaluation results were recorded in Tables 7 and Figure 7 middle.

[0081] Table 7 Sensory evaluation scores of commercial low-salt fermented sauces and high-temperature thermal reactions

[0082]

[0083] The results in Tables 7 and 7 show that the low-salt fermented sauce prepared by the technical solution is superior to the commercially available sauce in terms of thickness, color and aroma, and the body and umami taste are not much different, and it has obvious advantages in the market. The above results show that the technical solution of the present invention can obtain a low-salt sauce with moderate body viscosity, bright reddish brown, bright and shiny color, rich sauce flavor, rich and mellow taste in a very short period (about 7 days). Compared with traditional fermentation, the fermentation cycle is greatly shortened, and the product quality is guaranteed, which has broad market application prospects.

[0084] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A method for preparing a low-salt fermented sauce, characterized in that: The following steps are involved: 1) mixing the steamed soybeans with the fried wheat, inoculating Aspergillus oryzae for mixed culture to obtain finished koji; 2) mixing the koji, steamed and cooked soybeans with water to prepare the prepared soybean koji, and adding a composite protease to perform enzymolysis to obtain an enzymolysis solution; 3) The enzymatic solution is inactivated, cooled, filtered, and then the enzymatic supernatant is obtained. Lactobacillus plantarum and active dry yeast are added, mixed, and fermented at 28-32° C. The inoculation amounts of Lactobacillus plantarum and active dry yeast are 10 4 -10 6 CFU / g, 10 3 -10 5 CFU / g; 4) The fermented enzymatic hydrolysate is subjected to heat treatment to obtain a low-salt fermented sauce; In the enzymatic hydrolysis process of step 2), 1% (w / w) cellulase was first added to soybean koji for hydrolysis at 55°C for 3 hours, and then 0.5% (w / w) neutral protease and 0.8% (w / w) flavor protease were added to continue the hydrolysis for 3 hours, and finally 0.4% (w / w) medium-temperature α-amylase was added for hydrolysis at 60°C for 3 hours.

2. The preparation method according to claim 1, characterized in that The fermentation time in step 3) is 44-52h.

3. The preparation method according to claim 1, characterized in that: In step 2), the mixing ratio of koji, steamed and cooked soybeans and water is 1:1:3 (w / w).

4. The preparation method according to claim 1, characterized in that: Step 1) The mixing ratio of steamed soybeans and fried wheat is 9:1 (w / w).

5. The preparation method according to claim 1, characterized in that: In step 1), the water content of the fried wheat is below 10%.

6. The preparation method according to any one of claims 1 to 5, characterized in that: Step 4) The heat treatment time is 7-9h.

7. The preparation method according to any one of claims 1 to 5, characterized in that: Step 4) The heat treatment temperature is 75-90°C.

8. The preparation method according to claim 7, characterized in that: The heat treatment temperature is 85-90°C.

9. A low-salt fermented sauce, characterized in that: The low-salt fermented sauce is prepared by the preparation method described in any one of claims 1-8.

10. A sauce, characterized in that: The sauce comprises the low-salt fermented sauce according to claim 9.

Images