Preparation method of probiotic-rich soy sauce and probiotic soy sauce

Abstract

The invention discloses a preparation method of a probiotic-rich soy sauce and the probiotic soy sauce. By preparing a beneficial koji agent, probiotics are added in the koji-making stage of the soy sauce, and a beneficial fermentation liquid is prepared at the same time, so that the probiotics are added in the koji-making and fermentation stages of the soy sauce, the flavor level of the soy sauce is significantly improved, and the influence of miscellaneous bacteria on the flavor of the soy sauce is weakened. The addition of probiotics can inhibit the growth of corrupt microorganisms during the fermentation process and within the shelf life, thereby ensuring the safety of the soy sauce. The invention proposes for the first time to directly add plant lactobacillus to the sterilized soy sauce to inhibit the growth of harmful miscellaneous bacteria and significantly improve the storage time of the soy sauce.

Description

Technical Field

[0001] The invention belongs to the field of soy sauce brewing, and particularly relates to a preparation method of probiotic-rich soy sauce and the probiotic soy sauce. Background Art

[0002] Soy sauce is a popular traditional Chinese fermented condiment with a history of more than 3,000 years. It has a unique flavor and pure umami taste, and can also provide attractive colors for various dishes. As people pay more and more attention to food safety issues and have higher and higher requirements for the nutritional value of food, soy sauce, as an indispensable element in daily life, is also constantly improving in terms of quality. The traditional soy sauce brewing process mainly uses fungi such as Aspergillus oryzae, Zygosaccharomyces rouxii, and Torulopsis saccharomyces, and the brewing process rarely involves the participation of probiotics.

[0003] Probiotics have many health benefits for the human body, such as regulating intestinal flora, improving constipation, relieving lactose intolerance, reducing the incidence of hyperlipidemia, improving human immunity, and preventing allergies, Helicobacter pylori infection and other diseases. At the same time, probiotics have been used in a variety of foods, among which probiotic yogurt has won wide favor among consumers.

[0004] However, at present, there is no report on how to add probiotics to brewed soy sauce to achieve the best effect of improving its quality. At the same time, food preservatives are often added to the existing soy sauce system, which has poor safety. Summary of the invention

[0005] The purpose of this section is to summarize some aspects of embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the specification abstract and the invention title of this application to avoid blurring the purpose of this section, the specification abstract and the invention title, and such simplifications or omissions cannot be used to limit the scope of the present invention.

[0006] In view of the above problems and / or the problems existing in the prior art, the present invention is proposed.

[0007] Therefore, the object of the present invention is to overcome the deficiencies in the prior art and provide a method for preparing a probiotic-rich soy sauce.

[0008] In order to solve the above technical problems, the present invention provides the following technical solution: a method for preparing probiotic-rich soy sauce, comprising:

[0009] Preparation of Yiqu agent: activating Lactobacillus plantarum ATCC 14917 and Pediococcus pentosaceus ATCC 8081, inoculating them into a culture medium, culturing them statically, adding xylooligosaccharides, fructooligosaccharides, isomaltooligosaccharides and soybean oligosaccharides, mixing them, and preparing Yiqu agent;

[0010] Preparation of beneficial fermentation liquid: Lactobacillus plantarum ATCC 14917 and Pediococcus pentosaceus ATCC 8081 are cultured and activated, inoculated into a culture medium, and then added into a salt solution with a salt content of 6-10% of the same mass to prepare a beneficial fermentation liquid;

[0011] Raw material pretreatment: pour the raw material into clean water, add oligofructose, stir, and sterilize to obtain the pretreated raw material;

[0012] Preparation of soy sauce koji: cooling the pretreated raw materials, inoculating Aspergillus oryzae and beneficial koji agent, stirring evenly and then stacking and culturing. When the surface of koji is covered with yellow-green spores, the koji is mature;

[0013] Probiotic-rich soy sauce: add salt water to Daqu and ferment for 3 months, the fermentation temperature in the first month is 45°C, and beneficial fermentation liquid is added in the first month of fermentation, and the fermentation temperature in the second and third months is 30°C. After the fermentation is completed, filter to obtain a raw sample of probiotic-rich soy sauce;

[0014] After the obtained raw sample of probiotic-rich soy sauce is sterilized, Lactobacillus plantarum and Lactobacillus pentosus are added to obtain the probiotic-rich soy sauce.

[0015] As a preferred embodiment of the preparation method of the present invention, in which: in the preparation of the beneficial koji agent, the contents of xylooligosaccharides, fructooligosaccharides, isomaltooligosaccharides and soybean oligosaccharides respectively account for 2-4% of the mass percentage of the substance after static culture.

[0016] As a preferred embodiment of the preparation method of the present invention, wherein: in the preparation of the Yiqu agent, the static culture time is 20 to 24 hours.

[0017] As a preferred embodiment of the preparation method of the present invention, the raw materials are pretreated, wherein the bran includes a mixture of soybean bran and fried wheat bran in a mass ratio of 6:4.

[0018] As a preferred solution of the preparation method of the present invention, wherein: the raw material is pretreated, wherein the content of oligofructose accounts for 0.2-04% of the total mass of bran and water.

[0019] As a preferred embodiment of the preparation method of the present invention, in the preparation of soy sauce koji, Aspergillus oryzae is inoculated at a mass fraction of 0.3-0.5%, and the inoculation amount of the beneficial koji agent is 1-2%.

[0020] As a preferred solution of the preparation method of the present invention, the content of the beneficial fermentation liquid is 1-2% of the total volume of the Daqu.

[0021] As a preferred embodiment of the preparation method of the present invention, wherein: the addition of Lactobacillus plantarum and Lactobacillus pentosus obtains a probiotic-rich soy sauce, wherein the inoculation amount of Lactobacillus plantarum and Lactobacillus pentosus is 10 6 CFU / mL.

[0022] Another object of the present invention is to overcome the deficiencies in the prior art and provide a product obtained by a preparation method of probiotic-rich soy sauce.

[0023] Beneficial effects of the present invention:

[0024] (1) The present invention provides a method for preparing probiotic-rich soy sauce, which comprises preparing a probiotic agent, adding probiotics during the koji-making stage of the soy sauce, and preparing a probiotic fermentation liquid at the same time, thereby adding probiotics during the koji-making and fermentation stages of the soy sauce, significantly improving the flavor level of the soy sauce, and weakening the influence of miscellaneous bacteria on the flavor of the soy sauce. The addition of probiotics can inhibit the growth of spoilage microorganisms during the fermentation process and during the shelf life, thereby ensuring the safety of the soy sauce.

[0025] (2) The present invention proposes for the first time to directly add Lactobacillus plantarum to sterilized soy sauce to inhibit the growth of harmful bacteria and significantly increase the shelf life of soy sauce; Lactobacillus plantarum is a natural biological preservative with development potential because it can inhibit the growth of spoilage bacteria and pathogenic bacteria through nutritional competition and the production of safe and efficient antibacterial substances. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative labor. Among them:

[0027] Figure 1 This is a graph showing the results of the Oxford cup antibacterial experiment in an embodiment of the present invention. DETAILED DESCRIPTION

[0028] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the embodiments of the specification.

[0029] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0030] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive with other embodiments.

[0031] The determination of total bacterial count in soy sauce refers to GB 4789.2-2016 "Determination of total bacterial count in food microbiology examination";

[0032] The flavor substance analysis method of the present invention is as follows: 5 mL of a sample diluted 10 times is taken into a 15 mL headspace bottle, 1.0 g of NaCl and a mixed standard solution (30 μL of 0.125 mg / L 2-octanol and 50 μL of 0.125 mg / L methyl nonadecanoate) are added, and the mixture is balanced at 55° C. and 600 r / min for 10 min, and then an aged 75 μm CAR / PDMS extraction head is inserted for headspace adsorption for 40 min. After the adsorption is completed, the extraction head is pulled out and inserted into the GC injection port, and GC-MS analysis is performed after decomposition at 250° C. for 5 min.

[0033] In the sensory evaluation analysis of the present invention, 10 trained professionals (male: female = 1:1) were selected to evaluate and score the color, aroma and taste of different finished soy sauce products, with a full score of 10. The specific sensory scoring table is as follows:

[0034]

[0035] In addition: the color score is obtained by red score*40%+yellow score*40%+black score*20; the taste score is obtained by umami score*50%+sweetness score*50%.

[0036] Raw materials used in the present invention:

[0037] Lactobacillus plantarum ATCC 14917, Pediococcus pentosaceus ATCC 8081: Shanghai Beinuo Biotechnology Co., Ltd.; Aspergillus oryzae 3.042: Yishui Jinrun Biotechnology Co., Ltd., Fructooligosaccharide: Angel Yeast; other raw materials are commercially available unless otherwise specified.

[0038] The MRS culture medium of the present invention comprises the following formulas: 10 g protein Chen, 5 g beef powder, 4 g yeast powder, 2 g glucose, 1 ml Tween 80, 2 g dipotassium hydrogen phosphate, 5 g sodium acetate, 2 g triammonium citrate, 0.2 g magnesium sulfate, 0.05 g manganese sulfate, 15 g agar powder, and 1000 ml distilled water. After packaging, the medium is sterilized at 121° C. under high pressure for 15 to 20 minutes.

[0039] Example 1

[0040] (1) Preparation of Yiquji: Lactobacillus plantarum ATCC 14917 and Pediococcus pentosaceus ATCC 8081 were cultured in MRS medium until 10 8 CFU / mL, inoculate it into new MRS medium with an inoculum size of 2%. After static culture for 24 h, add xylooligosaccharides, fructooligosaccharides, isomaltooligosaccharides and soybean oligosaccharides (mass ratio of 1:1:1:1) into the medium in sequence at a total mass fraction of 2%.

[0041] (2) Preparation of fermentation liquid: Lactobacillus plantarum ATCC 14917 and Pediococcus pentosaceus ATCC 8081 were cultured in MRS medium until 10 8 CFU / mL, it was inoculated into new MRS medium at a 2% inoculation amount, cultured statically for 24 hours, and then added into 9% salt (sodium chloride) solution.

[0042] (3) Raw material pretreatment: Use a balance to weigh 600 g of soybeans and 400 g of roasted wheat, pour in 1200 g of clean water, add 0.4% of oligofructose by mass, the water temperature is 87°C, stir with a glass rod, put into a suitable container, and sterilize at 121°C for 20 minutes.

[0043] (4) Preparation of soy sauce koji: The sterilized raw materials were cooled to 40° C., and the pre-activated Aspergillus oryzae was inoculated into the koji culture medium at a mass fraction of 0.5%, and 2% of Yiqu agent was inoculated at the same time. After stirring evenly, the mixture was piled and cultured. The incubator temperature was controlled at 30° C.;

[0044] After 15 hours, turn the koji and break up the accumulated koji, which is equivalent to the second inoculation, and culture it flat at 30℃.

[0045] After 22 hours of cultivation, the koji material was broken up again and continued to be spread out for cultivation;

[0046] After 40 hours, when the surface of Daqu is covered with yellow-green spores, Daqu is mature.

[0047] (5) Fermentation of probiotic-rich soy sauce: Add an equal mass of saline solution with a salt content of 10% to the soy sauce koji and ferment for 3 months. The fermentation temperature in the first month is 45°C. At the same time, 2% of the total volume of the koji is added with beneficial fermentation liquid in the first month. The fermentation temperature in the second and third months is 30°C. After the fermentation is completed, filter to obtain a raw sample of probiotic-rich soy sauce.

[0048] (6) Sterilization treatment: The obtained probiotic-rich soy sauce sample was sterilized at 121°C for 20 min, and then 10 6 CFU / mL of plant lactobacillus is added to obtain probiotic-rich soy sauce.

[0049] Example 2

[0050] No probiotics added after sterilization:

[0051] (1) Preparation of Yiquji: Lactobacillus plantarum ATCC 14917 and Pediococcus pentosaceus ATCC 8081 were cultured in MRS medium until 10 8 CFU / mL, inoculated into new MRS medium at a 2% inoculation amount, and after static culture for 24 hours, oligofructose was added into the medium at a mass fraction of 2%.

[0052] (2) Preparation of fermentation liquid: Lactobacillus plantarum ATCC 14917 and Pediococcus pentosaceus ATCC 8081 were cultured in MRS medium until 10 8 CFU / mL, it was inoculated into new MRS medium at a 2% inoculation amount, cultured statically for 24 hours, and then added into 9% salt (sodium chloride) solution.

[0053] (3) Raw material pretreatment: Use a balance to weigh 600 g of soybeans and 400 g of roasted wheat, pour in about 1200 g of clean water, add 0.4% of oligofructose by mass, the temperature of the clean water is about 87°C, stir with a glass rod, put into a suitable container, and sterilize at 121°C for 20 minutes.

[0054] (4) Preparation of soy sauce koji: The sterilized raw materials were cooled to 40° C., 0.5% mass fraction of Aspergillus oryzae was inoculated into the koji culture medium and 2% of Yiqu agent was inoculated, the mixture was stirred evenly and then piled for culture. The temperature of the incubator was controlled at about 30° C.

[0055] After 15 hours, turn over the koji and break up the accumulated koji, which is equivalent to the second inoculation, and culture it flat at 30℃.

[0056] After 22 hours of cultivation, the koji material is broken up again and continued to be spread out for cultivation. After 40 hours, when the surface of the koji is covered with yellow-green spores, the koji is mature.

[0057] (5) Fermentation of probiotic-rich soy sauce: Add salt water with an equal mass of 10% salt content to the soy sauce koji and ferment for 3 months. The fermentation temperature in the first month is 45°C. At the same time, 2% of the total volume of the koji is added with beneficial fermentation liquid in the first month of fermentation. The fermentation temperature in the second and third months is 30°C. After the fermentation is completed, filter to obtain a raw sample of probiotic-rich soy sauce.

[0058] (6) Sterilization treatment: The raw sample of the probiotic-rich soy sauce is sterilized at 121° C. for 20 min to obtain the soy sauce.

[0059] Example 3

[0060] No beneficial koji agent and beneficial fermentation liquid are added:

[0061] (1) Raw material pretreatment: weigh about 600 g of soybeans and about 400 g of roasted wheat on a balance, pour in about 1200 g of clean water, add 0.4% of oligofructose by mass, the temperature of the clean water is about 87°C, stir with a glass rod, put into a suitable container, and sterilize at 121°C for 20 minutes.

[0062] (2) Preparation of soy sauce koji: The sterilized raw materials were cooled to about 40°C, and the seed koji of Aspergillus oryzae that had been activated in advance was inoculated into the koji culture medium at a mass fraction of 0.5%. After stirring evenly, the koji was piled up and cultured. The temperature of the incubator was controlled at about 30°C. After 15 hours, the koji was turned over and the piled koji materials were broken up, which was equivalent to the second inoculation, and the koji materials were spread out and cultured at 30°C. After 22 hours of culture, the koji materials were broken up again and continued to be spread out. After 40 hours, when the surface of the koji was covered with yellow-green spores, the koji was mature.

[0063] (3) Fermentation of probiotic-rich soy sauce: 10% salt water was added to the soy sauce koji and fermented for 3 months. The fermentation temperature was 45° C. in the first month and 30° C. in the second and third months. After the fermentation was completed, the raw sample of probiotic-rich soy sauce was obtained by filtration.

[0064] (4) Sterilization treatment: The obtained probiotic-rich soy sauce samples were sterilized at 121°C for 20 min, and 10 6 CFU / mL of Lactobacillus plantarum and Lactobacillus pentosus was used to obtain the probiotic-rich soy sauce.

[0065] Example 4

[0066] Traditional brewing, including:

[0067] (1) Raw material pretreatment: weigh about 600 g of soybeans and about 400 g of roasted wheat on a balance, pour in about 1200 g of clean water, add 0.4% of oligofructose by mass, the temperature of the clean water is about 87°C, stir with a glass rod, put into a suitable container, and sterilize at 121°C for 20 minutes.

[0068] (2) Preparation of soy sauce koji: The sterilized raw materials were cooled to about 40° C., Aspergillus oryzae was inoculated into the koji culture medium at a mass fraction of 0.5%, and the mixture was stirred evenly and then piled for culture. The temperature of the incubator was controlled at about 30° C.

[0069] After 15 hours, turn over the koji and break up the accumulated koji, which is equivalent to the second inoculation, and culture it flat at 30℃.

[0070] After 22 hours of cultivation, the koji material is broken up again and continued to be spread out for cultivation. After 40 hours, when the surface of the koji is covered with yellow-green spores, the koji is mature.

[0071] (3) Fermentation of probiotic-rich soy sauce: 10% salt water was added to the soy sauce koji and fermented for 3 months. The fermentation temperature was 45° C. in the first month and 30° C. in the second and third months. After the fermentation was completed, the raw soy sauce sample was filtered to obtain the raw soy sauce sample.

[0072] (4) Sterilization treatment: The raw soy sauce sample is sterilized at 121° C. for 20 min to obtain the soy sauce.

[0073] Table 1 Sensory scoring table of soy sauce samples with different sterilization treatments

[0074]

[0075] Table 2 Types and relative contents of volatile flavor substances in different soy sauces

[0076]

[0077] As shown in Table 1, the sensory scores of Examples 1 and 2 to which beneficial koji agent and beneficial fermentation liquid were added during the soy sauce fermentation stage were higher than those of Examples 3 and 4 to which beneficial koji agent and beneficial fermentation liquid were not added.

[0078] Adding beneficial koji and beneficial fermentation liquid during the fermentation process of soy sauce can obtain better flavor richness. The increase of esters after fermentation with beneficial koji and beneficial fermentation liquid is the most obvious, and the increase of ester aroma in soy sauce is the most obvious. Among them, the oligofructose contained in beneficial koji promotes the growth of probiotics, inhibits the spoilage microorganisms in koji making, and is conducive to the formation of reddish brown color of soy sauce.

[0079] As can be seen from Table 2, among the volatile substances detected in the four samples, esters and alcohols are the most abundant in each sample. Comparing the relative contents of different substances in each sample, the flavor substances in Example 1 are mainly composed of esters and alcohols, among which the relative content of esters is as high as 80.35%. Esters are volatile and easily perceived by human sense of smell, and have a greater impact on the overall flavor of soy sauce.

[0080] Compared with the soy sauce described in Example 4, the esters and alcohols in the soy sauce with the addition of beneficial koji and beneficial fermentation liquid are significantly increased, and esters and alcohols are also the main providers of the flavor of the soy sauce. The proportion of aldehydes in the soy sauce that has not been fermented by probiotics is high. Adding plant lactobacillus in the brewing process of soy sauce can degrade aldehydes in the production process of soy sauce, converting aldehydes into alcohols or acids to increase the flavor of the soy sauce and reduce the influence of alcohols.

[0081] Table 3 Comparison of flavor active substances in different soy sauces

[0082]

[0083]

[0084]

[0085] As shown in Table 3, esters and alcohols are the main sources of flavor for soy sauce. Overall, the ester and alcohol content in Example 1 fermented with beneficial fermentation agent and beneficial fermentation liquid is higher. Adding beneficial fermentation liquid and beneficial fermentation agent to alcohol flavor substances mainly promotes the accumulation of isobutanol, isopropanol, and 2-methyl-1-butanol. The increase of guaiacol, 4-ethylguaiacol, and 4-vinylguaiacol contributes to the formation of the characteristic sauce flavor of soy sauce. The increase in ethyl lactate content is related to the fermentation and production of lactic acid by plant lactobacillus, and the lactic acid generated by its metabolism can be esterified with ethanol to promote the formation of ethyl lactate.

[0086] At the same time, the ethanol content in the soy sauce of Example 1 is significantly higher than that of Example 4. The increase in ethanol content promotes the esterification reaction between ethanol and organic acid, so that the content of ethyl ester substances in the soy sauce increases. At the same time, compared with Example 4, the lactic acid content in Example 1 is also greatly increased. Lactic acid is an important organic acid in soy sauce, has a soft and palatable sour feeling, is an important source of sour taste in soy sauce, and is also a precursor of lactic acid ester substances, which can promote the formation of soy sauce aroma.

[0087] Comparative Example 1

[0088] Compared with Example 1, the beneficial koji agent is not prepared:

[0089] (1) Preparation of fermentation liquid: Lactobacillus plantarum ATCC 14917 and Pediococcus pentosaceus ATCC 8081 were cultured in MRS medium until 10 8 CFU / mL, inoculated into new MRS medium at a 2% inoculum, cultured statically for 24 h, and then added into 10% saline solution.

[0090] (2) Raw material pretreatment: Weigh 600 g of soybeans and 400 g of roasted wheat on a balance, pour in 1200 g of clean water, add 0.4% by mass of oligofructose, the temperature of the clean water is 87°C, stir with a glass rod, put into a suitable container, and sterilize at 121°C for 20 minutes.

[0091] (3) Preparation of soy sauce koji: The sterilized raw materials were cooled to 40° C., Aspergillus oryzae was inoculated into the koji culture medium at a mass fraction of 0.5%, and the mixture was stirred evenly and then piled for culture. The incubator temperature was controlled at 30° C.;

[0092] After 15 hours, turn the koji and break up the accumulated koji, which is equivalent to the second inoculation, and culture it flat at 30℃.

[0093] After 22 hours of cultivation, the koji material was broken up again and continued to be spread out for cultivation;

[0094] After 40 hours, when the surface of Daqu is covered with yellow-green spores, Daqu is mature.

[0095] (4) Fermentation of probiotic-rich soy sauce: Add salt water with an equal mass of 10% salt content to the soy sauce koji and ferment for 3 months. The fermentation temperature in the first month is 45°C. At the same time, 2% of the total volume of the koji is added with beneficial fermentation liquid in the first month. The fermentation temperature in the second and third months is 30°C. After the fermentation is completed, filter to obtain a raw sample of probiotic-rich soy sauce.

[0096] (5) Sterilization treatment: The obtained probiotic-rich soy sauce sample was sterilized at 121°C for 20 min, and then 10 6 CFU / mL of plant lactobacillus is added to obtain probiotic-rich soy sauce.

[0097] Comparative Example 2

[0098] Compared with Example 1, the beneficial fermentation liquid is not prepared:

[0099] (1) Preparation of Yiquji: Lactobacillus plantarum ATCC 14917 and Pediococcus pentosaceus ATCC 8081 were cultured in MRS medium until 10 8 CFU / mL, inoculated in a new MRS medium at a 2% inoculation amount, and after static culture for 24 hours, xylooligosaccharides, fructo-oligosaccharides, isomaltooligosaccharides and soybean oligosaccharides were added to the medium in sequence at a mass fraction of 2%.

[0100] (2) Raw material pretreatment: Weigh 600 g of soybeans and 400 g of roasted wheat on a balance, pour in 1200 g of clean water, add 0.4% by mass of oligofructose, the temperature of the clean water is 87°C, stir with a glass rod, put into a suitable container, and sterilize at 121°C for 20 minutes.

[0101] (3) Preparation of soy sauce koji: The sterilized raw materials were cooled to 40° C., 0.5% mass fraction of Aspergillus oryzae was inoculated into the koji culture medium, and 2% of Yiqu agent was inoculated at the same time, and the mixture was stirred evenly and then piled for culture. The incubator temperature was controlled at 30° C.;

[0102] After 15 hours, turn the koji and break up the accumulated koji, which is equivalent to the second inoculation, and culture it flat at 30℃.

[0103] After 22 hours of cultivation, the koji material was broken up again and continued to be spread out for cultivation;

[0104] After 40 hours, when the surface of Daqu is covered with yellow-green spores, Daqu is mature.

[0105] (4) Fermentation of probiotic-rich soy sauce: 10% salt water was added to the soy sauce koji and fermented for 3 months. The fermentation temperature was 45° C. in the first month and 30° C. in the second and third months. After the fermentation was completed, the raw sample of probiotic-rich soy sauce was obtained by filtration.

[0106] (5) Sterilization treatment: The obtained probiotic-rich soy sauce sample was sterilized at 121°C for 20 min, and then 10 6 CFU / mL of plant lactobacillus is added to obtain probiotic-rich soy sauce.

[0107] Provide comparative test results of the beneficial effects of flavor substances.

[0108] Table 4 Comparison of flavor substances

[0109]

[0110]

[0111]

[0112] Comparative Example 3

[0113] (1) The soy sauce prepared in Example 4 was bottled and left uncovered for 1 month, which was designated as Group A.

[0114] (2) The soy sauce prepared in Example 1 was bottled and left uncovered for 1 month, which was designated as Group B.

[0115] (3) Sensory evaluation was conducted on Group A and Group B. The results are shown in the following table:

[0116] Table 5 Sensory comparison

[0117]

[0118]

[0119] (4) Isolate the spoilage microorganisms in group A and isolate a strain of Staphylococcus aureus. Perform the Oxford cup antibacterial test. The results are as follows: Figure 1 shown.

[0120] Antibacterial experiment:

[0121] The antibacterial ability of the bacteria was determined by the Oxford cup antibacterial test. 10 mL of 2% sterile water agar was used as the bottom culture medium, and a sterile Oxford cup was placed horizontally on it with tweezers. Staphylococcus aureus was diluted to 10% with a semi-solid LB medium at 40-50°C. 6 ~10 7 CFU / mL.

[0122] The upper culture medium is placed on top of the lower culture medium in the Oxford cup, and is approximately 10 mL of semi-solid LB culture medium containing Staphylococcus hominis.

[0123] After the culture medium solidified, 100 μL of different exogenous additives were added to the Oxford cup and diffused at room temperature (4°C) for 3 to 5 h.

[0124] Finally, they were cultured at 37°C for 24 hours. No exogenous additives were added to the control group. The antibacterial ability was judged by the size of the inhibition zone, and the diameter of the inhibition zone was determined using a vernier caliper (including the diameter of the Oxford cup, which was 8 mm), and the results were repeated three times.

[0125] Among them, the exogenous additive is the cell-free supernatant of Lactobacillus plantarum (and Pediococcus pentosaceus):

[0126] Lactobacillus plantarum (and Pediococcus pentosaceus ) were cultured in MRS medium at 37°C for 12 h and then centrifuged at 8000 × g for 10 min at 4°C to obtain cell-free supernatant;

[0127] The cell-free supernatant was collected by centrifugation;

[0128] The antibacterial activity of cell-free supernatant and bacteria against contaminating bacteria was determined by Oxford cup inhibition test.

[0129] like Figure 1 It can be seen that Lactobacillus plantarum and Pediococcus pentosaceus both have inhibitory effects on Staphylococcus hominis, which indicates that Lactobacillus plantarum and Pediococcus pentosaceus can indeed effectively inhibit the growth of soy sauce contaminating bacteria.

[0130] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention can be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the present invention.

Claims

1. A method for preparing probiotic-rich soy sauce, characterized in that: include, Preparation of beneficial koji: after activating Lactobacillus plantarum ATCC 14917 and Pediococcus pentosaceus ATCC 8081, inoculate them into a culture medium, statically culture them, add xylooligosaccharides, fructooligosaccharides, isomaltooligosaccharides and soybean oligosaccharides, mix them, and prepare beneficial koji, wherein the total content of xylooligosaccharides, fructooligosaccharides, isomaltooligosaccharides and soybean oligosaccharides accounts for 2% of the mass percentage of the substance after static culture, wherein the mass ratio of xylooligosaccharides, fructooligosaccharides, isomaltooligosaccharides and soybean oligosaccharides is 1:1:1:1; Preparation of beneficial fermentation liquid: Lactobacillus plantarum ATCC 14917 and Pediococcus pentosaceus ATCC 8081 are cultured and activated, inoculated into a culture medium, and then added into a salt solution with a salt content of 9% of the same mass to prepare a beneficial fermentation liquid after static culture; Raw material pretreatment: pour soybeans and fried wheat into clean water, add oligofructose, stir, and sterilize to obtain pretreated raw materials, wherein the content of oligofructose accounts for 0.2-0.4% of the total mass of the raw materials and clean water; Preparation of soy sauce koji: cooling the pretreated raw materials, inoculating Aspergillus oryzae and a beneficial koji agent, stirring evenly and then stacking and culturing. When the surface of the koji is covered with yellow-green spores, the koji is mature, wherein Aspergillus oryzae is inoculated at a mass fraction of 0.3-0.5%, and the inoculation amount of the beneficial koji agent is 1-2%; Probiotic-rich soy sauce: adding salt water to Daqu and fermenting for 3 months, the fermentation temperature in the first month is 45° C., and adding beneficial fermentation liquid in the first month of fermentation, and the fermentation temperature in the second and third months is 30° C. After the fermentation is completed, filtering is performed to obtain a raw sample of probiotic-rich soy sauce, wherein the content of the beneficial fermentation liquid is 1-2% of the total volume of the Daqu; After the obtained probiotic-rich soy sauce raw sample is sterilized, Lactobacillus plantarum is added to obtain probiotic-rich soy sauce, wherein the inoculation amount of Lactobacillus plantarum is 10 6 CFU / mL.

2. The preparation method according to claim 1, characterized in that: In the preparation of the Yiqu agent, the static culture time is 20 to 24 hours.

3. The preparation method according to claim 1, characterized in that: The raw material pretreatment comprises a mixture of soybeans and fried wheat in a mass ratio of 6:

4.

4. The probiotic-rich soy sauce prepared by the preparation method as claimed in any one of claims 1 to 3.

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