Brewed food fungicide drying protective agent, application thereof and preparation method of brewed food fungicide

Abstract

The invention belongs to the technical field of microorganisms, and discloses a drying protective agent for a brewed food fungicide, application of the drying protective agent and a preparation method of the brewed food fungicide. The brewing food fungicide drying protective agent provided by the invention comprises sterilized sorghum hydrolysate, the sorghum hydrolysate is hydrolysate obtained after a sorghum suspension is subjected to enzymolysis with alpha-amylase and saccharifying enzyme. The protective agent provided by the invention contains rich polysaccharides, monosaccharides, proteins, vitamins, minerals, organic acids and antioxidant substances, can provide comprehensive nutritional support for strains, has multiple protection mechanisms, can reduce damage in the drying and storage processes, improves the survival rate and activity of the strains in the drying and storage processes, and improves the survival rate of the strains in the drying and storage processes. And rapid recovery and metabolism start of the strain are promoted. And meanwhile, the single sorghum hydrolysate is used as a protective agent, so that the purity of the brewing process and the flavor stability of the product can be ensured. Therefore, the drying protective agent provided by the invention has obvious advantages and wide application prospects.

Description

Technical Field

[0001] The invention belongs to the technical field of biochemical additives, and in particular relates to a brewing food microbial agent drying protective agent and an application thereof and a brewing food microbial agent preparation method. Background Art

[0002] Grain brewed food is a food made from grains using microbial fermentation and brewing technology. There are many varieties of grain brewed food, the most important of which is wine, vinegar, sauce and soy sauce, which are also indispensable brewed condiments in Chinese life. In addition, pickled pickles, fermented bean curd, cheese and other fermented foods are also traditional foods that are widely loved by the Chinese people.

[0003] At present, the research on brewing food microbial agents mainly focuses on the screening of protective agents and process optimization. Since a single protective agent provides a limited protection mechanism, the number of live bacteria in the microbial agent prepared using it is not high. The composite protective agent developed by compounding traditional single protective agents can increase the number of live bacteria in the microbial agent to a certain extent. For example, the protective agent provided by CN102304487A: 15% skimmed milk powder, 8% maltodextrin, 6% cyclodextrin, 1% trehalose, 1% sucrose. A direct-injection high-activity concentrated solid fruit and vegetable acetic acid bacterial agent was prepared by freeze-drying using this protective agent. The number of live bacteria in the agent was tested to be 10 9 CFU / g or more. However, various protective agents can usually only significantly improve the survival rate of the strain during freeze-drying, but the survival rate of the strain has not been significantly improved during spray drying. Therefore, freeze-drying is still the preferred method for bacterial agent technology. However, freeze-drying is costly for the production process of traditional brewing products. In addition, the existing protective agents have limited antioxidant capacity and a single protective mechanism, which limit their protective ability. In addition, insufficient nutritional support affects the rapid recovery of the strain and metabolic initiation, and cannot meet the production needs of traditional brewing products. Summary of the invention

[0004] In view of the above technical problems, the present invention provides a brewing food bacterial agent drying protective agent and its application and brewing food bacterial agent preparation method. The drying protective agent has low cost and can significantly improve the survival rate of brewing food bacteria during freeze drying or spray drying. It can be used to prepare brewing food bacterial agent and applied to traditional brewing food production.

[0005] In order to achieve the above-mentioned object of the invention, the present invention adopts the following technical solutions:

[0006] In a first aspect, the present invention provides a brewing food microbial agent drying protective agent, comprising sterilized sorghum hydrolyzate; a method for preparing the sorghum hydrolyzate comprises the following steps:

[0007] S1: After sorghum is crushed and sieved, sorghum powder is mixed with water to prepare sorghum suspension;

[0008] S2: performing a composite enzymatic hydrolysis on the sorghum suspension, and the enzymatic hydrolysis is terminated when the sugar content reaches 15-20° Bx and is stable and no longer changes, thereby obtaining a sorghum enzymatic hydrolyzate; the composite enzymatic hydrolysis is first performed by using α-amylase and then by using saccharifying enzyme;

[0009] S3: performing enzyme inactivation treatment and solid-liquid separation on the sorghum enzymatic hydrolysate, collecting the liquid phase, and obtaining a sorghum hydrolysate containing sorghum hydrolysate.

[0010] The main component of sorghum is starch, and it also contains a certain amount of dietary fiber. These carbohydrates are hydrolyzed by amylase and saccharifying enzyme to produce polysaccharides and monosaccharides such as dextrin, oligosaccharides, glucose and maltose. At the same time, proteins, vitamins, minerals, organic acids and some antioxidants in sorghum, such as phenolic compounds, tannins, flavonoids and anthocyanins, will dissolve in water during the preparation process. Therefore, the sorghum hydrolyzate provided by the present invention contains rich polysaccharides, monosaccharides, proteins, vitamins and minerals, organic acids and antioxidants. These ingredients can provide comprehensive nutritional support for the strain, promote its rapid recovery and metabolic initiation, and effectively protect the cell structure during the drying process, reduce damage and increase survival rate. Among them, polysaccharides can form a protective film to reduce water evaporation, antioxidants can reduce oxidative stress, amino acids and peptides can protect protein structure and maintain cell activity; at the same time, sorghum hydrolyzate is a complex of carbohydrates, proteins and other substances. During the drying process, polysaccharides and proteins undergo covalent reactions to form a complex. This complex forms a protective film on the surface of the bacterial agent, which helps prevent damage to the bacteria from the external environment, maintain its activity and increase the survival rate of the strain.

[0011] When used in industry, the sorghum hydrolyzate containing sorghum hydrolyzate provided by the present invention can be directly used without sterilization; when used in laboratory experiments or when industrial requirements are high, the sorghum hydrolyzate containing sorghum hydrolyzate provided by the present invention can be used after sterilization. The sterilization method can be selected from high-temperature and high-pressure steam sterilization, ultraviolet sterilization, ozone sterilization, membrane filtration sterilization and other sterilization methods, and the specific selection can be determined according to the actual application scenario and needs.

[0012] Sorghum hydrolyzate protects the bacteria through a variety of mechanisms. Drying the protective agent for brewing food bacteria into a liquid or solid preparation can also play a protective role.

[0013] S1 The crushing of sorghum helps the carbohydrates, proteins, vitamins and other substances in sorghum to dissolve in water. The sorghum can be crushed to a particle size of ≤0.5mm.

[0014] The solid-liquid separation in S2 can be carried out by filtration or centrifugation, and the corresponding filtrate or supernatant is collected, which is the enzymatic hydrolyzate containing the sorghum hydrolyzate.

[0015] Furthermore, the mass volume ratio of sorghum flour and water in S1 is 1:8-10, and the time is 0.5-1h.

[0016] Furthermore, the α-amylase in S2 is a thermostable α-amylase, the addition amount is 0.5%-1.5% of the mass of the sorghum flour, the enzymolysis pH is 5.0-6.0, the enzymolysis temperature is 88-92° C., and the enzymolysis time is 0.5-1h.

[0017] Thermostable α-amylase can maintain high activity and stability at higher temperatures, which helps to efficiently hydrolyze starch in sorghum, improve hydrolysis efficiency, shorten reaction time, and also facilitate the dissolution of other substances in sorghum. The enzymatic hydrolysis conditions listed can ensure that starch is fully degraded into dextrins, oligosaccharides and a small amount of monosaccharides.

[0018] Furthermore, the saccharifying enzyme in step 2 is a saccharifying enzyme derived from Aspergillus niger, the added amount is 2%-3% of the mass of sorghum flour, the enzymatic hydrolysis pH is 4.0-4.5, the enzymatic hydrolysis temperature is 55-60°C, and the enzymatic hydrolysis time is greater than or equal to 1h.

[0019] The saccharifying enzyme derived from Aspergillus niger can be widely used in the food, brewing and other industries, and can break down polysaccharides or oligosaccharides into monosaccharides.

[0020] Furthermore, the protective agent consists of the sorghum hydrolyzate.

[0021] Sorghum hydrolysate is derived from sorghum itself, and the hydrolytic enzymes used are endogenous or externally added during the production of brewed food. Therefore, using sterilized sorghum hydrolysate alone as a protective agent for brewed food microbial agents will not introduce foreign substances, and can not only effectively protect the brewing bacteria, improve their survival rate and activity, but also ensure the purity of the traditional brewing process and the flavor stability of the product.

[0022] Furthermore, the protective agent also includes one or more of small molecule polyols, sugars and polymer protective agents.

[0023] By rationally combining sorghum hydrolyzate with existing strain protectants, the drying protection effect of the strain can be significantly improved to meet different application requirements.

[0024] Among them, small molecule polyols include but are not limited to glycerol, mannitol, etc.; sugars include but are not limited to trehalose, sucrose, glucose, lactose, sucrose, maltodextrin, etc.; polymer protective agents include but are not limited to milk protein, gum arabic, konjac gum, sodium carboxymethyl cellulose, etc.

[0025] In a second aspect, the present invention also provides the use of the above-mentioned brewing food bacterial agent drying protective agent in the preparation of fermentation bacteria products used in brewing food, wherein the protective agent is used as a bacterial strain protective agent for the fermentation bacteria.

[0026] The dry protective agent provided by the present invention can be used to prepare fermented bacteria products used in brewing food, including but not limited to: on the one hand, it is used to produce direct-injection starter for the production of dairy products and fermented food; on the other hand, for brewing food bacteria that can be developed as probiotics, the protective agent can be used to develop solid beverages, tablets, capsules, etc. In addition, it can also be used to preserve the living bacteria in brewing food to ensure its long-term stability and activity.

[0027] Furthermore, the fermentation strains include but are not limited to strains used in brewing wine, vinegar, paste and soy sauce.

[0028] Furthermore, the fermentation bacteria are of the genus Lactobacillus or Saccharomyces.

[0029] Furthermore, the protective agent is used as a spray drying and freeze drying protective agent for the fermentation strain.

[0030] In a third aspect, the present invention provides a method for preparing a food brewing agent, the preparation method comprising the following steps:

[0031] S1: Cultivating and activating the fermentation bacteria used for brewing food in a culture medium;

[0032] S2: centrifuging the fermented bacterial culture obtained by the above S1 to collect bacterial sludge;

[0033] S3: The bacterial sludge obtained by centrifugation in S2 is mixed with the above-mentioned drying protective agent to obtain a bacterial suspension, and the bacterial suspension is spray-dried or freeze-dried to obtain a brewing food bacterial agent.

[0034] Furthermore, the final concentration of sorghum hydrolyzate in the bacterial suspension in S3 is 9.7-12.2 wt % based on sorghum flour. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. 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 paying creative work.

[0036] Figure 1 This is an electron microscope photo of the spray-dried bacterial agent in Example 8 of the present invention.

[0037] Figure 2This is an electron microscope photograph of the vacuum freeze-dried bacterial agent in Example 8 of the present invention. DETAILED DESCRIPTION

[0038] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0039] The strains involved in the following examples and comparative examples are: Saccharomyces cerevisiae, with a collection number of CICC NO.32359, provided by the China Industrial Microbiological Culture Collection Administration Center; Lactobacillus acetotolerans, with a collection number of CICC NO.10774, provided by the China Industrial Microbiological Culture Collection Administration Center.

[0040] The culture medium involved in the following examples and comparative examples: MRS liquid culture medium (g / L): glucose 20g / L, peptone 10g / L, beef extract powder 8g / L, yeast extract powder 4g / L, dipotassium hydrogen phosphate 2g / L, diammonium hydrogen citrate 2g / L, sodium acetate 5g / L, magnesium sulfate 0.2g / L, manganese sulfate 0.04g / L, Tween 80 1g / L, pH 6.0, sterilized at 121°C for 20min; MRS broth culture medium (g / L): 5.224g MRS broth culture medium powder was dissolved in 100mL ultrapure water, sterilized at 121°C for 20min, and then stored in a refrigerator at 4°C for standby use; MRS solid culture medium (g / L): 5.224g MRS broth culture medium, 1.5-2g agar, added ultrapure water to make up to 100mL, sterilized at 121°C for 20min, and then stored in a refrigerator at 4°C for standby use.

[0041] The enzymes involved in the following examples: saccharifying enzyme was purchased from Wuxi Xuemei Enzyme Technology Co., Ltd.; high temperature resistant α-amylase was purchased from Angel Enzyme (Yichang) Co., Ltd.

[0042] Unless otherwise specified, other experimental materials and instruments can be purchased through commercial channels.

[0043] The detection method of the viable bacterial count of the bacterial agent involved in the following verification example is based on the national standard "GB 4789.2-2022 National Food Safety Standard Food Microbiology Examination Total Colony Count Determination".

[0044] Example 1

[0045] This embodiment provides a sorghum hydrolyzate, which is prepared by the following steps:

[0046] S1: Weigh 200 g of sorghum, grind it with an ultrafine grinder for 3 min, and then pass it through a 60-mesh sieve; mix sorghum powder and water in a mass ratio of 1:8, and stir for 1 h until it is fully mixed to obtain a sorghum suspension;

[0047] S2: The pH of the sorghum suspension was adjusted to 5.5, and the temperature was raised to 90°C. 2 mL of thermostable α-amylase was added, and enzymolysis was performed for 30 min. The temperature was then lowered to 60°C, the pH was reduced to 4.0, and 4 g of saccharifying enzyme was added. After enzymolysis for 1 h, the sugar content reached 20°Bx and did not change, and the sorghum enzymolyzate was obtained;

[0048] S3: The sorghum enzymatic hydrolysate was heated to 100°C and maintained for 20 min to inactivate the enzyme. After filtering, the sorghum enzymatic hydrolysate was centrifuged at 5000 rpm / min for 15 min to obtain the supernatant, which was the sorghum hydrolysate.

[0049] Example 2

[0050] This embodiment provides a sorghum hydrolyzate, which is prepared by the following steps:

[0051] S1: Weigh 200 g of sorghum, grind it with an ultrafine grinder for 4 min, and then pass it through a 60-mesh sieve; mix sorghum powder and water in a mass ratio of 1:9, stir for 1 h until fully mixed, and obtain a sorghum suspension;

[0052] S2: The pH of the sorghum suspension was adjusted to 6, and the temperature was raised to 88°C. 2 mL of thermostable α-amylase was added, and enzymolysis was performed for 40 min. The temperature was then lowered to 55°C, the pH was reduced to 4.5, and 6 g of saccharifying enzyme was added. After enzymolysis for 1 h, the sugar content reached 18°Bx and did not change, and the sorghum enzymolysate was obtained.

[0053] S3: The sorghum enzymatic hydrolysate was heated to 100°C and maintained for 20 min to inactivate the enzyme. After filtering, the sorghum enzymatic hydrolysate was centrifuged at 5000 rpm / min for 15 min to obtain the supernatant, which was the sorghum hydrolysate.

[0054] Example 3

[0055] This embodiment provides a sorghum hydrolyzate, which is prepared by the following steps:

[0056] S1: Weigh 200 g of sorghum, grind it with an ultrafine grinder for 4 min, and then pass it through a 60-mesh sieve; mix sorghum powder and water in a mass ratio of 1:10, stir for 1 h until fully mixed, and obtain a sorghum suspension;

[0057] S2: The pH of the sorghum suspension was adjusted to 5, and the temperature was raised to 92°C. 3 mL of thermostable α-amylase was added, and the enzyme was hydrolyzed for 60 min. Then the temperature was lowered to 55°C, the pH was reduced to 4.2, and 5 g of saccharifying enzyme was added. After the enzyme was hydrolyzed for 1 h, the sugar content reached 15°Bx and did not change, and the sorghum hydrolyzate was obtained;

[0058] S3: The sorghum enzymatic hydrolysate was heated to 100°C and maintained for 20 min to inactivate the enzyme. After filtering, the sorghum enzymatic hydrolysate was centrifuged at 5000 rpm / min for 15 min to obtain the supernatant, which was the sorghum hydrolysate.

[0059] Example 4

[0060] This embodiment provides a brewing food microbial agent drying protective agent, which is prepared by sterilizing the sorghum hydrolyzate provided in Example 1. The sterilization condition is 121° C. for 20 minutes.

[0061] Example 5

[0062] This embodiment provides a brewing food microbial agent drying protective agent, which is prepared by sterilizing the sorghum hydrolyzate provided in Example 2. The sterilization condition is 121° C. for 20 minutes.

[0063] Example 6

[0064] This embodiment provides a brewing food microbial agent drying protective agent, which is prepared by sterilizing the sorghum hydrolyzate provided in Example 3. The sterilization condition is 121° C. for 20 minutes.

[0065] Example 7

[0066] This embodiment provides a brewing food microbial agent drying protective agent, which is composed of the sorghum hydrolyzate provided in Example 1, skim milk powder and mannitol in a mass ratio of 8:1:1.

[0067] Example 8

[0068] This embodiment provides a brewer's yeast agent, which is prepared by the following steps:

[0069] S1: Saccharomyces cerevisiae was inoculated into YPD liquid medium, cultured at 30°C for 24 h, and then re-inoculated into YPD liquid medium at a 2% inoculation rate for activation culture, which was repeated twice.

[0070] S2: The activated Saccharomyces cerevisiae was inoculated into a YPD liquid medium at an inoculum rate of 2%, and the culture was statically cultured at 30°C for 24 hours, and then the bacterial sludge was collected by centrifugation at 6000 rpm / min for 10 minutes at 4°C, and washed twice with 0.85% physiological saline. The obtained bacterial sludge was added to a protective agent, which was the dry protective agent for brewed food bacterial agent provided in Example 4, and the bacterial suspension was fully vortexed and mixed to prepare a bacterial suspension, and the final concentration of sorghum hydrolyzate in the bacterial suspension was 12.2wt% based on sorghum powder.

[0071] S3: The obtained bacterial suspension is subjected to spray drying to obtain a brewer's yeast inoculum. The spray drying conditions are: inlet temperature 110°C, outlet temperature 55°C, fan frequency 60Hz, striker interval 5s, execution 0.3s, and feed rate 250mL / h; or the obtained bacterial suspension is pre-frozen at -80°C for 8h and then transferred to a vacuum freeze dryer for freeze drying to obtain a brewer's yeast inoculum. The freeze drying parameters are -80°C, vacuum degree 1.0pa, and freezing time 24h.

[0072] Example 9

[0073] This embodiment provides a brewer's yeast agent, and its preparation method is basically the same as that of Example 8, except that in step 2, the final concentration of sorghum hydrolyzate in the bacterial suspension is 9.7wt% based on sorghum flour, and the remaining steps are the same as those of Example 8.

[0074] Comparative Example 1

[0075] This comparative example provides a brewer's yeast agent, and its preparation method is basically the same as that of Example 8, except that the protective agent used in step 2 is trehalose, and the final concentration of trehalose is 10wt%. The remaining steps are the same as those of Example 8.

[0076] Comparative Example 2

[0077] This comparative example provides a brewer's yeast agent, and its preparation method is basically the same as that of Example 8, except that the protective agent used in step 2 is maltodextrin, and the final concentration of maltodextrin is 10wt%. The remaining steps are the same as those of Example 8.

[0078] Comparative Example 3

[0079] This comparative example provides a brewer's yeast agent, and its preparation method is basically the same as that of Example 8, except that the protective agent used in step 2 is skim milk powder, and the final concentration of skim milk powder is 10wt%. The remaining steps are the same as those of Example 8.

[0080] Comparative Example 4

[0081] This comparative example provides a brewer's yeast agent, and its preparation method is basically the same as that of Example 8, except that the protective agent used in step 2 is lactose, and the final concentration of lactose is 10wt%. The remaining steps are the same as those of Example 8.

[0082] Comparative Example 5

[0083] This comparative example provides a brewer's yeast agent, and its preparation method is basically the same as that of Example 8, except that no protective agent is used in step 2, and the bacterial mud and 0.85wt% physiological saline are prepared into a bacterial suspension in a mass ratio of 1:7, and the remaining steps are the same as those of Example 8.

[0084] Verification Example 1

[0085] According to the method of the national standard "GB4789.2-2022 National Food Safety Standard Food Microbiology Test Colony Count Determination", the viable bacterial counts before and after drying of the bacterial agents involved in Examples 8 and 9 and Comparative Examples 1-5 were calculated, and the survival rate was calculated by repeating 5 times. The survival rate calculation formula is as follows:

[0086] Survival rate (%) = (number of viable bacteria after drying / number of viable bacteria before drying) × 100%.

[0087] The spray-dried and vacuum freeze-dried yeast inoculants provided in Example 8 had viable counts of 5.13×10 10 \5.39×10 10 The spray-dried and vacuum freeze-dried yeast inoculants provided in Example 9 had viable counts of 4.97×10 10 \5.29×10 10 CFU / g The survival rates of the brewer's yeast agents provided in Examples 8 and 9 and Comparative Examples 1-5 are shown in Table 1.

[0088] Table 1 Survival rate of live bacteria of Saccharomyces cerevisiae inoculants with different protective agents

[0089] Group Protective agent Spray drying survival rate Vacuum freeze drying survival rate Example 8 12.2wt% Sorghum hydrolysate 82.69±1.31％ 86.97±0.86％ Example 9 9.7wt% Sorghum hydrolysate 80.24±1.24％ 85.39±1.17％ Comparative Example 1 10wt% trehalose 74.24±1.33％ 81.65±1.93％ Comparative Example 2 10wt% maltodextrin 38.56±1.96％ 52.79±2.33％ Comparative Example 3 10wt% skim milk powder 65.87±2.57％ 72.43±1.56％ Comparative Example 4 10wt% Lactose 59.84±1.46％ 68.67±1.48％ Comparative Example 5 Normal saline 0.76±0.14％ 1.13±0.09％

[0090] Example 10

[0091] This embodiment provides an acid-resistant lactobacillus agent for traditional vinegar brewing, which is prepared by the following steps:

[0092] S1: Acid-resistant lactobacillus was inoculated into MRS liquid culture medium, cultured at 30° C. for 20 h, and then re-inoculated into MRS liquid culture medium at a 2% inoculation amount for activation culture, which was repeated twice.

[0093] S2: The activated acid-resistant lactobacillus was inoculated into MRS liquid culture medium at an inoculum amount of 2%, and cultured at 30°C for 24 hours, and then centrifuged at 6000 rpm / min for 10 minutes at 4°C to collect the bacterial sludge, and washed twice with 0.85% physiological saline. The obtained bacterial sludge was added to the protective agent, which was the brewed food bacterial agent protective agent provided in Example 5, and fully vortexed to mix to form a bacterial suspension, and the final concentration of sorghum hydrolyzate in the bacterial suspension was 10.8wt% based on sorghum flour.

[0094] S3: The obtained bacterial suspension is subjected to spray drying to obtain an acid-resistant lactobacillus agent. The spray drying conditions are: inlet temperature 130°C, outlet temperature 70°C, fan frequency 60Hz, striker interval 5s, execution 0.3s, and feed rate 300mL / h; or the obtained bacterial suspension is pre-frozen at -80°C for 8h and then transferred to a vacuum freeze dryer for freeze drying to obtain an acid-resistant lactobacillus agent. The freeze drying parameters are -80°C, vacuum degree 1.0pa, and freezing time 24h.

[0095] Comparative Example 6

[0096] This comparative example is an acid-resistant lactobacillus agent brewed from traditional vinegar, and its preparation method is basically the same as that of Example 10, except that the protective agent used in step 2 is trehalose, and the final concentration of trehalose is 10wt%. The remaining steps are the same as those of Example 10.

[0097] Comparative Example 7

[0098] This comparative example is an acid-resistant lactobacillus agent for traditional vinegar brewing, and its preparation method is basically the same as that of Example 10, except that the protective agent used in step 2 is maltodextrin, and the final concentration of maltodextrin is 10wt%. The remaining steps are the same as those of Example 10.

[0099] Comparative Example 8

[0100] This comparative example is an acid-resistant lactobacillus agent for traditional vinegar brewing. Its preparation method is basically the same as that of Example 10, except that the protective agent used in step 2 is skim milk powder, and the final concentration of skim milk powder is 10wt%. The remaining steps are the same as those of Example 10.

[0101] Comparative Example 9

[0102] This comparative example is an acid-resistant lactobacillus agent for traditional vinegar brewing. Its preparation method is basically the same as that of Example 10, except that the protective agent used in step 2 is lactose, and the final concentration of lactose is 10wt%. The remaining steps are the same as those of Example 10.

[0103] Verification Example 2

[0104] According to the method of the national standard "GB4789.2-2022 National Food Safety Standard Food Microbiological Inspection Colony Count Determination", the number of live bacteria before and after drying of the bacterial agent involved in Example 10 and Comparative Examples 6-9 was calculated, and the number of live bacteria after drying was repeated 5 times to calculate the survival rate.

[0105] The viable counts of the acid-resistant Lactobacillus spray-dried and vacuum freeze-dried bacterial preparations provided in Example 10 were 1.64×10 11 / 1.81×10 11The survival rates of the acid-resistant lactobacillus agents provided in Examples 10 and 9 and Comparative Examples 6-9 are shown in Table 2.

[0106] Table 2 Survival rate of live bacteria of acid-resistant lactobacillus inoculants with different protective agents

[0107] Group Protective agent Spray drying survival rate Vacuum freeze drying survival rate Example 10 10.8wt% Sorghum hydrolysate 78.11±1.37％ 86.39±0.97％ Comparative Example 6 10wt% trehalose 73.57±3.67％ 80.65±1.12％ Comparative Example 7 10wt% maltodextrin 38.26±1.63％ 54.79±2.74％ Comparative Example 8 10wt% skim milk powder 69.64±1.62％ 77.43±2.38％ Comparative Example 9 10wt% Lactose 65.58±1.17％ 73.67±1.52％

[0108] The effective dosage of trehalose, maltodextrin, skim milk powder and starch as traditional strain protectants is generally between 5-15%. Trehalose, maltodextrin, skim milk powder and starch with a dosage of 10wt% were selected to compare the strain protection effect with the dry protective agent for brewed food bacteria provided by the present invention.

[0109] It can be seen from Tables 1 and 2 above that, whether in the spray drying method or the freeze drying method, the sorghum hydrolyzate provided by the present invention showed the highest strain survival rate, which was 74.11% and 82.39% respectively, and the standard deviation was between 0.8% and 1.4%. It had good stability during the drying process, indicating that sorghum hydrolyzate has significant advantages as a protective agent in improving the survival rate of strains.

[0110] The sorghum hydrolyzate provided by the present invention contains substances such as polysaccharides, monosaccharides, proteins, vitamins, and organic acids, which can provide carbon sources, nitrogen sources, and other essential nutrients for the strain, maintain the balance of osmotic pressure inside and outside the cell, reduce the damage of oxidative stress to the strain, and promote the rapid recovery of the strain; at the same time, the sugars and proteins in the sorghum hydrolyzate undergo covalent reactions during the drying process to form complexes. These complexes form a protective film on the surface of the bacterial agent, effectively preventing the external environment from damaging the bacterial body, maintaining the activity of the bacterial body, and thus significantly improving the survival rate of the strain.

[0111] In summary, the brewing food bacterial agent drying protective agent provided by the present invention is a new type of protective agent, which can be used to prepare high-activity brewing food strain products, is suitable for the production of various types of brewing foods, and provides a new choice for the brewing food industry.

[0112] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A drying protective agent for brewing food bacteria, It is characterized in that The invention comprises sorghum hydrolysate; and the preparation method of the sorghum hydrolysate comprises the following steps: S1: After sorghum is crushed and sieved, sorghum powder is mixed with water to prepare sorghum suspension; S2: performing a composite enzymatic hydrolysis on the sorghum suspension, and the enzymatic hydrolysis is terminated when the sugar content reaches 15-20° Bx and is stable and no longer changes, thereby obtaining a sorghum enzymatic hydrolyzate; the composite enzymatic hydrolysis is first performed by using α-amylase and then by using saccharifying enzyme; S3: performing enzyme inactivation treatment and solid-liquid separation on the sorghum enzymatic hydrolysate, collecting the liquid phase, and obtaining a sorghum hydrolysate containing sorghum hydrolysate.

2. The brewed food bacterial agent drying protective agent according to claim 1, It is characterized in that The mass volume ratio of sorghum flour to water in S1 is 1:8-10, and the mixing time is 0.5-1h; and / or The α-amylase in S2 is a thermostable α-amylase, the addition amount is 0.5%-1.5% of the mass of the sorghum flour, the enzymatic hydrolysis pH is 5.0-6.0, the enzymatic hydrolysis temperature is 88-92° C., and the enzymatic hydrolysis time is 0.5-1h; and / or The saccharifying enzyme in S2 is derived from Aspergillus niger, and the added amount is 2%-3% of the mass of sorghum flour, the enzymatic hydrolysis pH is 4.0-4.5, the enzymatic hydrolysis temperature is 55-60° C., and the enzymatic hydrolysis time is greater than or equal to 1 hour.

3. The brewed food bacterial agent drying protective agent according to claim 1, It is characterized in that The protective agent consists of the sorghum hydrolyzate.

4. The brewed food bacterial agent drying protective agent according to claim 1, It is characterized in that The protective agent also includes one or more of small molecule polyols, sugars and polymer protective agents.

5. Use of the brewed food bacterial agent drying protective agent according to any one of claims 1 to 4 in the preparation of fermented bacteria products used in brewed food, It is characterized in that The protective agent is a strain protective agent for the fermentation strain.

6. The use according to claim 5, It is characterized in that The fermentation strains include, but are not limited to, strains used in brewing wine, vinegar, paste and soy sauce.

7. The use according to claim 6, It is characterized in that The fermentation bacteria species are of the genus Lactobacillus or the genus Saccharomyces.

8. The use according to claim 5, It is characterized in that The protective agent is used as a spray drying and freeze drying protective agent for the fermentation strain.

9. A method for preparing a food brewing agent, It is characterized in that The preparation method comprises the following steps: S1: Cultivating and activating the fermentation bacteria used for brewing food in a culture medium; S2: centrifuging the fermented bacterial culture obtained by the above S1 culture to collect bacterial sludge; S3: The bacterial sludge obtained by centrifugation in S2 is mixed with the drying protective agent according to any one of claims 1 to 4 to obtain a bacterial suspension, and the bacterial suspension is spray-dried or freeze-dried to obtain a brewing food bacterial agent.

10. The preparation method according to claim 9, It is characterized in that The final concentration of sorghum hydrolyzate in the bacterial suspension in S3 is 9.7-12.2 wt % based on sorghum flour.

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