A postbiotic composition for anti-corrosion and antibacterial in food, its preparation method and application

Abstract

The present invention belongs to the field of microbial technology, and specifically relates to a postbiotic composition for anti-corrosion and antibacterial in food, its preparation method and application. The raw materials of the postbiotic composition include: inactivated cells of a compound probiotic and metabolites of the compound probiotic; the compound probiotic includes Lactobacillus casei Zhang, Bifidobacterium animalis subsp. lactis V9, Lactobacillus plantarum P-8 and Lactobacillus plantarum PB-2. Through the mutual cooperation of the above four strains, the present invention can more effectively convert the culture medium substrate into several organic acids and short-chain fatty acids with more excellent anti-corrosion and antibacterial effects, improving the anti-corrosion and antibacterial effects of the postbiotic composition.

Description

Technical Field

[0001] The present invention belongs to the field of microbial technology, and specifically relates to a postbiotic composition for anti-corrosion and antibacterial in food, its preparation method and application. Background Art

[0002] In industries such as food and medicine, anti-corrosion and antibacterial have always been important topics. Traditional chemical preservatives have potential safety hazards, while natural antibacterial substances produced by microorganisms have broad application prospects. As a type of beneficial microorganism, some strains of lactic acid bacteria have good antibacterial activity, but there is still room for improvement in the stability and effectiveness of relevant lactic acid bacteria powders in anti-corrosion and antibacterial.

[0003] Postbiotics is a new means of intervening in the intestinal ecosystem that has emerged in recent years. Currently, postbiotics have been regarded by the industrial community as the fourth generation of microecological products after probiotics, prebiotics, and synbiotics. The mechanisms of action of postbiotics mainly include regulating resident flora, enhancing epithelial barrier function, regulating local and systemic immunity, regulating systemic metabolism, and sending systemic signals through the nervous system. Although the effects of postbiotics on the microbiome may be temporary, they may still have important roles.

[0004] Currently, flour-based foods such as steamed buns and bread are prone to mildew and difficult to preserve. Since synthetic antioxidants and preservatives are far less safe than natural antioxidants and preservatives, which can easily cause concerns among consumers, there is an urgent need to find more natural antioxidants and preservatives that can effectively prevent or slow down the quality deterioration of flour-based foods during storage. Summary of the Invention

[0005] Aiming at the deficiencies of the prior art, the present invention provides a postbiotic composition for anti-corrosion and antibacterial in food, its preparation method and application.

[0006] To achieve the above object of the present invention, the specific technical solutions adopted by the present invention are as follows:

[0007] A postbiotic composition with biological anti-corrosion and antibacterial effects, the raw materials of the postbiotic composition include: inactivated cells of composite probiotics and metabolites of composite probiotics; the composite probiotics include Lactobacillus casei Zhang, Bifidobacterium animalis subsp. lactis V9, Lactobacillus plantarum P-8, and Lactobacillus plantarum PB-2;

[0008] Among them, the Lactobacillus casei Zhang is classified and named as Lactobacillus casei, and is preserved in the China General Microbiological Culture Collection Center, with the preservation number CGMCC No. 5469;

[0009] The Bifidobacterium animalis subsp. lactis V9 is taxonomically named Bifidobacterium animalis subsp. lactis and is deposited in the General Microbiological Center of the China Committee for Culture Collection of Microorganisms with the deposit number CGMCC No. 5470;

[0010] The Lactobacillus plantarum P-8 is taxonomically named Lactobacillus plantarum and is deposited in the General Microbiological Center of the China Committee for Culture Collection of Microorganisms with the deposit number CGMCC No. 6312;

[0011] The Lactobacillus plantarum PB-2 is taxonomically named Lactobacillus plantarum and is deposited in the General Microbiological Center of the China Committee for Culture Collection of Microorganisms with the deposit number CGMCC No. 5400.

[0012] Preferably, before inactivating the composite probiotics, the total cell count of the composite probiotics ≥ 5.0×10 10 CFU / g.

[0013] Preferably, the Lactobacillus casei Zhang, Bifidobacterium animalis subsp. lactis V9, Lactobacillus plantarum P-8 and Lactobacillus plantarum PB-2 are combined according to the ratio of colony forming unit numbers of 1:0.8 - 1.2:0.8 - 1.2:1.5 - 2.5.

[0014] More preferably, the Lactobacillus casei Zhang, Bifidobacterium animalis subsp. lactis V9, Lactobacillus plantarum P-8 and Lactobacillus plantarum PB-2 are combined according to the ratio of colony forming unit numbers of 1:1:1:2.

[0015] Preferably, the metabolites of the composite probiotics contain more than 50 mg / g of organic acids, more than 5 mg / g of short-chain fatty acids and more than 13 mg / mL of polypeptides.

[0016] More preferably, the organic acids include one or more of lactic acid, citric acid, salicylic acid, malic acid, benzoic acid, succinic acid, 4-hydroxyphenyllactic acid, oxalic acid or phenyllactic acid; the short-chain fatty acids include one or more of acetic acid, propionic acid, butyric acid, valeric acid or caproic acid; the polypeptides include one or more of dipeptides, tripeptides, tetrapeptides or pentapeptides.

[0017] The present invention also relates to a preparation method of the above postbiotic composition, including:

[0018] Inoculating the composite probiotic strains into a sterilized culture medium, fermenting at a constant temperature of 33 - 37 °C until the pH reaches 4.5 - 4.6, inactivating and drying to obtain the postbiotic composition.

[0019] Preferably, after the culture medium is prepared and before sterilization, it further includes a homogenization step.

[0020] More preferably, the temperature of homogenization is 55 - 65°C, the primary pressure is 18 - 20.0 Mpa, and the secondary pressure is 4 - 5.0 Mpa.

[0021] Preferably, the temperature during sterilization of the culture medium is 95°C, and the sterilization time is 30 min.

[0022] Preferably, after fermentation and before inactivation, it further includes a homogenization step, the temperature of homogenization is 55 - 65°C, the primary pressure is 18 - 20.0 Mpa, and the secondary pressure is 5.0 Mpa.

[0023] Preferably, the drying is spray drying.

[0024] The present invention also relates to the application of the above postbiotic composition in the preparation of products for improving the storage quality of food.

[0025] The present invention also relates to a food, and the ingredients of the food include the above postbiotic composition.

[0026] Preferably, by mass percentage, the addition amount of the postbiotic composition in the food is 0.01% - 20%, more preferably 0.1 - 1%, and even more preferably 0.3%.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] In the postbiotic composition of the present invention, the probiotic strains used for fermentation are optimized, and probiotic strains with different sources, different species, and different probiotic characteristics are selected. Through the mutual cooperation of four strains, Lactobacillus casei Zhang, Bifidobacterium animalis subsp. lactis V9, Lactobacillus plantarum P - 8, and Lactobacillus plantarum PB - 2, the culture medium substrate can be more effectively converted into several organic acids and short - chain fatty acids with more excellent anti - corrosion and antibacterial effects, improving the anti - corrosion and antibacterial effect of the postbiotic composition.

[0029] In the postbiotic composition of the present invention, Lactobacillus plantarum P - 8 and Lactobacillus plantarum PB - 2 are used, and the synergistic effect of the two strains is obvious in enhancing the anti - corrosion, antibacterial effect and sensory effect of food.

[0030] Biological material preservation

[0031] Lactobacillus casei Zhang, classified and named as Lactobacillus casei, was deposited in the General Microbiological Center of the China Committee for Culture Collection of Microorganisms on November 18, 2011. The deposit number is CGMCC No.5469, and the deposit address is No. 3, Yard 1, Beichen West Road, Chaoyang District, Beijing. The test result of this strain is viable.

[0032] Bifidobacterium animalis subsp. lactis V9, classified and named as Bifidobacterium animalis subsp. lactis, was deposited in the General Microbiological Center of the China Committee for Culture Collection of Microorganisms on November 18, 2011. The deposit number is CGMCC No.5470, and the deposit address is No. 3, Yard 1, Beichen West Road, Chaoyang District, Beijing. The test result of this strain is viable.

[0033] Lactobacillus plantarum P-8, classified and named as Lactobacillus plantarum, was deposited in the General Microbiological Center of the China Committee for Culture Collection of Microorganisms on June 28, 2012. The deposit number is CGMCC No.6312, and the deposit address is No. 3, Yard 1, Beichen West Road, Chaoyang District, Beijing. The test result of this strain is viable.

[0034] Lactobacillus plantarum PB-2, classified and named as Lactobacillus plantarum, was deposited in the General Microbiological Center of the China Committee for Culture Collection of Microorganisms on October 28, 2011. The deposit number is CGMCC No.5400, and the deposit address is No. 3, Yard 1, Beichen West Road, Chaoyang District, Beijing. The test result of this strain is viable.

[0035] Lactobacillus plantarum HM-05, classified and named as Lactobacillus plantarum, was deposited in the General Microbiological Center of the China Committee for Culture Collection of Microorganisms on October 29, 2012. The deposit number is CGMCC No.6739, and the deposit address is No. 3, Yard 1, Beichen West Road, Chaoyang District, Beijing. The test result of this strain is viable. Brief Description of the Drawings

[0036] Figure 1 It shows the bacterial contamination situation of the bread samples in Example 1 and Comparative Examples 1 - 5 of the present invention after storage at 25°C for 7 days;

[0037] Figure 2 It shows the bacterial contamination situation of the steamed bun samples in Example 1 and Comparative Examples 1 - 3 of the present invention after storage at 25°C for 7 days. Detailed Description of the Invention

[0038] Combined with specific embodiments below, the present invention will be further elaborated in detail. The following embodiments are not used to limit the present invention, but only to illustrate the present invention. For the experimental methods used in the following embodiments, unless otherwise specified, the experimental methods without specific conditions noted in the embodiments are usually carried out under conventional conditions. For the materials, reagents, etc. used in the following embodiments, unless otherwise specified, they can all be obtained from commercial channels.

[0039] Example 1

[0040] A postbiotic composition with biological anti-corrosion and antibacterial effects (denoted as postbiotic composition 1#), the raw materials of the postbiotic composition include: inactivated cells of composite probiotics and metabolites of composite probiotics; the composite probiotics are composed of Lactobacillus casei Zhang, Bifidobacterium animalis subsp. lactis V9, Lactobacillus plantarum P-8, and Lactobacillus plantarum PB-2.

[0041] The preparation method of the above postbiotic composition 1# is as follows:

[0042] 1) Weighing materials: Mix 4 wt% of glucose, 2 wt% of sucrose, 7.5 wt% of whey powder, 5 wt% of yeast powder, 2.5 wt% of sodium citrate, and the balance being water according to the proportional requirements.

[0043] 2) Dissolving materials: Dissolve the materials at 55 °C for 15 min to obtain a liquid material.

[0044] 3) Homogenization: At 60 °C, the first-stage pressure is 20.0 Mpa and the second-stage pressure is 5.0 Mpa.

[0045] 4) Sterilization: The homogenized liquid material is sterilized at 95 °C for 30 min.

[0046] 5) Cooling: The sterilized liquid material is cooled to 35 °C.

[0047] 6) Adding strains and lactase: Add probiotics to the liquid material: The total inoculation amount of the composition of Lactobacillus casei Zhang, Bifidobacterium animalis subsp. lactis V9, Lactobacillus plantarum P-8, and Lactobacillus plantarum PB-2 is 5×10 6 CFU / g (culture medium liquid material), the ratio is 1:1:1:2, and add lactase (enzyme activity of 5000 U / g) 0.5 mL / kg (liquid material) according to production requirements.

[0048] 7) Constant-temperature fermentation: Carry out constant-temperature fermentation at 35 °C until it stops at pH 4.5 - 4.6 (the viable count of probiotics ≥ 5.0×10 10 CFU / g);

[0049] 8) Inactivation: Mix maltodextrin at 20 g / kg (fermentation broth) according to production requirements, preheat to 60°C, homogenize at a primary pressure of 20.0 Mpa and a secondary pressure of 5.0 Mpa, and then perform sterilization inactivation (inactivation conditions: 85°C, 15 min);

[0050] 9) Spray drying: The inactivated bacterial suspension is spray-dried to obtain the postbiotic composition.

[0051] Example 2

[0052] A postbiotic composition with biological anti-corrosion and antibacterial effects, the raw materials of the postbiotic composition include: inactivated cells of compound probiotics and metabolites of compound probiotics; the compound probiotics are composed of Lactobacillus casei Zhang, Bifidobacterium animalis subsp. lactis V9, Lactobacillus plantarum P-8, and Lactobacillus plantarum PB-2;

[0053] The difference between this example (denoted as postbiotic composition 1-1#) and Example 1 is only that the inoculation ratios of each probiotic and the constant-temperature fermentation process parameters are different, specifically as follows:

[0054] The ratio of Lactobacillus casei Zhang, Bifidobacterium animalis subsp. lactis V9, Lactobacillus plantarum P-8, and Lactobacillus plantarum PB-2 is 1:0.8:0.8:1.5;

[0055] Perform constant-temperature fermentation at 33°C and stop when the pH reaches 4.5 - 4.6 (the viable count of probiotics ≥ 5.0×10 10 CFU / g).

[0056] Example 3

[0057] A postbiotic composition with biological anti-corrosion and antibacterial effects, the raw materials of the postbiotic composition include: inactivated cells of compound probiotics and metabolites of compound probiotics; the compound probiotics are composed of Lactobacillus casei Zhang, Bifidobacterium animalis subsp. lactis V9, Lactobacillus plantarum P-8, and Lactobacillus plantarum PB-2;

[0058] The difference between this example (denoted as postbiotic composition 1-2#) and Example 1 is only that the inoculation ratios of each probiotic and the constant-temperature fermentation process parameters are different, specifically as follows:

[0059] The ratio of Lactobacillus casei Zhang, Bifidobacterium animalis subsp. lactis V9, Lactobacillus plantarum P-8, and Lactobacillus plantarum PB-2 is 1:1.2:1.2:2.5;

[0060] Perform constant-temperature fermentation at 37°C and stop when the pH reaches 4.5 - 4.6 (the viable count of probiotics ≥ 5.0×10 10 CFU / g).

[0061] Comparative Example 1

[0062] The difference between this comparative example (denoted as postbiotic composition 2#) and Example 1 is only that Lactobacillus plantarum PB-2 is replaced by Lactobacillus plantarum HM-05.

[0063] The preparation method of the above-mentioned postbiotic composition 2# is as follows:

[0064] 1) Weighing: Mix 4 wt% glucose, 2 wt% sucrose, 7.5 wt% whey powder, 5 wt% yeast powder, 2.5 wt% sodium citrate, and the balance being water according to the proportional requirements;

[0065] 2) Dissolving the raw materials: Dissolve the raw materials at 55 °C for 15 min to obtain a liquid material;

[0066] 3) Homogenization: At 60 °C, the first-stage pressure is 20.0 Mpa and the second-stage pressure is 5.0 Mpa;

[0067] 4) Sterilization: Sterilize the homogenized liquid material at 95 °C for 30 min;

[0068] 5) Cooling: Cool the sterilized liquid material to 35 °C;

[0069] 6) Adding strains and lactase: Add probiotics to the liquid material: The total inoculation amount of the composition of Lactobacillus casei Zhang, Bifidobacterium animalis subsp. lactis V9, Lactobacillus plantarum P-8, and Lactobacillus plantarum HM-05 is 5×10 6 CFU / g (culture medium liquid material), with a ratio of 1:1:1:2, and add lactase (enzyme activity of 5000 U / g) 0.5 mL / kg (liquid material) according to production requirements;

[0070] 7) Constant-temperature fermentation: Conduct constant-temperature fermentation at 35 °C until it stops at pH 4.5 - 4.6 (the viable count of probiotics ≥ 5.0×10 10 CFU / g);

[0071] 8) Inactivation: Mix maltodextrin 20 g / kg (fermented liquid material) according to production requirements, preheat it to 60 °C, homogenize it under the first-stage pressure of 20.0 Mpa and the second-stage pressure of 5.0 Mpa, and then conduct sterilization inactivation (inactivation conditions: 85 °C, 15 min);

[0072] 9) Spray drying: Obtain the said postbiotic composition by spray drying the inactivated bacterial suspension.

[0073] Comparative Example 2

[0074] The difference between this comparative example (denoted as postbiotic composition 3#) and Example 1 is only that the total inoculation amount of the composition of Lactobacillus casei Zhang, Bifidobacterium animalis subsp. lactis V9, Lactobacillus plantarum P-8, and Lactobacillus plantarum PB-2 is 5×10 6CFU / g (culture medium liquid), the ratio of 1:1:1:2 is replaced with the total inoculation amount of the composition of Lactobacillus casei Zhang, Bifidobacterium animalis subsp. lactis V9, Lactobacillus plantarum P-8 and Lactobacillus plantarum PB-2 being 5×10 6 CFU / g (culture medium liquid), with a ratio of 1:1:1:1.

[0075] The preparation method of the above postbiotic composition 3# is as follows:

[0076] 1) Weighing materials: Mix 4 wt% glucose, 2 wt% sucrose, 7.5 wt% whey powder, 5 wt% yeast powder, 2.5 wt% sodium citrate, and the balance being water according to the proportional requirements;

[0077] 2) Dissolving materials: Dissolve the materials at 55°C for 15 min to obtain a liquid;

[0078] 3) Homogenization: At 60°C, the first-stage pressure is 20.0 Mpa and the second-stage pressure is 5.0 Mpa;

[0079] 4) Sterilization: Sterilize the homogenized liquid at 95°C for 30 min;

[0080] 5) Cooling: Cool the sterilized liquid to 35°C;

[0081] 6) Adding strains and lactase: Add probiotics to the liquid: The total inoculation amount of the composition of Lactobacillus casei Zhang, Bifidobacterium animalis subsp. lactis V9, Lactobacillus plantarum P-8 and Lactobacillus plantarum PB-2 is 5×10 6 CFU / g (culture medium liquid), with a ratio of 1:1:1:1, and add lactase (enzyme activity 5000 U / g) 0.5 mL / kg (liquid) according to production requirements;

[0082] 7) Constant-temperature fermentation: Conduct constant-temperature fermentation at 35°C until it stops at pH 4.5 - 4.6 (the viable count of probiotics ≥ 5.0×10 10 CFU / g);

[0083] 8) Inactivation: Mix maltodextrin 20 g / kg (fermented liquid) according to production requirements, preheat to 60°C, homogenize at the first-stage pressure of 20.0 Mpa and the second-stage pressure of 5.0 Mpa, and then conduct sterilization inactivation (inactivation conditions: 85°C, 15 min);

[0084] 9) Spray drying: Obtain the above postbiotic composition by spray drying the inactivated bacterial suspension.

[0085] Comparative Example 3

[0086] The difference between this comparative example (denoted as postbiotic composition 4#) and Example 1 is only that the spray drying process in the preparation steps is replaced with a vacuum freeze-drying process.

[0087] The preparation method of the above postbiotics composition 4# is as follows:

[0088] 1) Weighing materials: Mix 4 wt% glucose, 2 wt% sucrose, 7.5 wt% whey powder, 5 wt% yeast powder, 2.5 wt% sodium citrate, and the balance being water according to the proportional requirements;

[0089] 2) Dissolving materials: Dissolve the materials at 55 °C for 15 min to obtain a liquid material;

[0090] 3) Homogenization: At 60 °C, the first-stage pressure is 20.0 Mpa and the second-stage pressure is 5.0 Mpa;

[0091] 4) Sterilization: Sterilize the homogenized liquid material at 95 °C for 30 min;

[0092] 5) Cooling: Cool the sterilized liquid material to 35 °C;

[0093] 6) Adding strains and lactase: Add probiotics to the liquid material: The total inoculation amount of the composition of Lactobacillus casei Zhang, Bifidobacterium animalis subsp. lactis V9, Lactobacillus plantarum P-8, and Lactobacillus plantarum PB-2 is 5×10 6 CFU / g (culture medium liquid material), with a ratio of 1:1:1:2, and add lactase (enzyme activity of 5000 U / g) 0.5 mL / kg (liquid material) according to production requirements;

[0094] 7) Constant-temperature fermentation: Conduct constant-temperature fermentation at 35 °C until it stops at pH 4.5 - 4.6 (the viable count of probiotics ≥ 5.0×10 10 CFU / g);

[0095] 8) Inactivation: Mix maltodextrin 20 g / kg (fermented liquid material) according to production requirements, preheat to 60 °C, homogenize at the first-stage pressure of 20.0 Mpa and the second-stage pressure of 5.0 Mpa, and then conduct sterilization inactivation (inactivation conditions: 85 °C, 15 min);

[0096] 9) Vacuum freeze-drying: Obtain the above postbiotics composition by vacuum freeze-drying the inactivated bacterial suspension.

[0097] Comparative Example 4

[0098] The difference between this comparative example (denoted as postbiotics composition 5#) and Example 1 is only that the composite probiotics do not contain Lactobacillus plantarum PB-2, and the total inoculation amount of Lactobacillus plantarum remains unchanged.

[0099] The preparation method of the above postbiotics composition 5# is as follows:

[0100] 1) Weighing the materials: Mix 4 wt% glucose, 2 wt% sucrose, 7.5 wt% whey powder, 5 wt% yeast powder, 2.5 wt% sodium citrate, and the balance being water according to the proportional requirements;

[0101] 2) Dissolving the materials: Dissolve the materials at 55 °C for 15 min to obtain a liquid material;

[0102] 3) Homogenization: At 60 °C, the first-stage pressure is 20.0 Mpa and the second-stage pressure is 5.0 Mpa;

[0103] 4) Sterilization: Sterilize the homogenized liquid material at 95 °C for 30 min;

[0104] 5) Cooling: Cool the sterilized liquid material to 35 °C;

[0105] 6) Adding strains and lactase: Add probiotics to the liquid material: The total inoculation amount of the composition of Lactobacillus casei Zhang, Bifidobacterium animalis subsp. lactis V9, and Lactobacillus plantarum P-8 is 5×10 6 CFU / g (culture medium liquid material), with a ratio of 1:1:3, and add lactase (enzyme activity of 5000 U / g) 0.5 mL / kg (liquid material) according to production requirements;

[0106] 7) Constant-temperature fermentation: Conduct constant-temperature fermentation at 35 °C until it stops at pH 4.5 - 4.6 (the viable count of probiotics ≥ 5.0×10 10 CFU / g);

[0107] 8) Inactivation: Mix maltodextrin 20 g / kg (fermented liquid material) according to production requirements, preheat to 60 °C, homogenize at the first-stage pressure of 20.0 Mpa and the second-stage pressure of 5.0 Mpa, and then conduct sterilization inactivation (inactivation conditions: 85 °C, 15 min);

[0108] 9) Spray drying: Obtain the postbiotic composition by spray drying the inactivated bacterial suspension.

[0109] Comparative Example 5

[0110] The difference between this comparative example (denoted as postbiotic composition 6#) and Example 1 is only that the composite probiotics do not contain Lactobacillus plantarum P-8, and the total inoculation amount of Lactobacillus plantarum remains unchanged.

[0111] The preparation method of the above postbiotic composition 6# is as follows:

[0112] 1) Weighing the materials: Mix 4 wt% glucose, 2 wt% sucrose, 7.5 wt% whey powder, 5 wt% yeast powder, 2.5 wt% sodium citrate, and the balance being water according to the proportional requirements;

[0113] 2) Dissolving the materials: Dissolve the materials at 55 °C for 15 min to obtain a liquid material;

[0114] 3) Homogenization: 60°C, primary pressure 20.0 Mpa, secondary pressure 5.0 Mpa;

[0115] 4) Sterilization: The homogenized liquid is sterilized at 95°C for 30 min;

[0116] 5) Cooling: The sterilized liquid is cooled to 35°C;

[0117] 6) Adding strains and lactase: Probiotics are added to the liquid: The total inoculation amount of the composition of Lactobacillus casei Zhang, Bifidobacterium animalis subsp. lactis V9 and Lactobacillus plantarum PB - 2 is 5×10 6 CFU / g (culture medium liquid), with a ratio of 1:1:3, and lactase (enzyme activity 5000 U / g) 0.5 mL / kg (liquid) is added according to production requirements;

[0118] 7) Constant - temperature fermentation: Carry out constant - temperature fermentation at 35°C until the pH reaches 4.5 - 4.6 and stop (the viable count of probiotics ≥ 5.0×10 10 CFU / g);

[0119] 8) Inactivation: Mix maltodextrin 20 g / kg (fermented liquid) according to production requirements, preheat to 60°C, homogenize at primary pressure 20.0 Mpa and secondary pressure 5.0 Mpa, and then carry out sterilization inactivation (inactivation conditions: 85°C, 15 min);

[0120] 9) Spray drying: The inactivated bacterial suspension is spray - dried to obtain the post - biotic composition.

[0121] Effect test

[0122] Test example 1 Detection of beneficial metabolites and their contents

[0123] By targeted and non - targeted detection of beneficial metabolites and their contents in the post - biotic composition, the results are shown in Table 1. From the results in the table, it can be seen that the post - biotic contains various active substances such as organic acids and short - chain fatty acids. Its mechanism of action may be to inhibit the growth of microorganisms by reducing the pH value, or it may be to form micropores on the cell membrane, resulting in increased cell permeability, inhibiting the formation of pathogenic biofilms, and then inhibiting the growth of microorganisms, playing an anti - corrosion and antibacterial role.

[0124] Table 1 Non - targeted / targeted detection of beneficial metabolites and their contents in post - biotic composition 1#

[0125]

[0126] Test example 2 Experimental verification of anti - corrosion and antibacterial in bread

[0127] Apply the postbiotic composition to bread products and evaluate the characteristics such as the flavor and storage of the bread. The addition amount of the postbiotic is 0.3% (calculated based on the solid content). The experiment is divided into 10 groups, namely the blank control group, the sodium dehydroacetate group, the postbiotic group 1#, the postbiotic group 1-1#, the postbiotic group 1-2#, the postbiotic group 2#, the postbiotic group 3#, the postbiotic group 4#, the postbiotic group 5#, and the postbiotic group 6#. The experimental grouping and formula are shown in Table 2.

[0128] Table 2 Bread formula table

[0129]

[0130] Measure the specific volume of each batch of bread within 5 minutes after baking out of the oven, measure the pH value and titratable acidity the next day, and store each batch of bread at 25°C, observing and recording the mold contamination situation on the bread surface every day. Measure the pH, acidity TA, mold and yeast counts of the bread on the 7th day of storage. The measurement results are shown in Table 3 and Table 4.

[0131] Table 3 Measurement results of bread indicators after baking (n = 3, x ± SD)

[0132]

[0133] Note: Data in the same column with the same superscript letter indicate that there is no significant difference in the data of the same column (p > 0.05).

[0134] It can be seen from the data in Table 3 that there is no significant difference in the specific volume of the samples in the blank group, the sodium dehydroacetate group and the postbiotic group after baking, and there is no significant difference in the pH value and titratable acidity of each group of bread.

[0135] Table 4 Measurement results of bread indicators after 7 days of storage at 25°C (n = 3, x ± SD)

[0136]

[0137] Note: Data in the same column without the same superscript letter indicate the significance of the difference in the data of the same column (p < 0.05).

[0138] The observation and recording results of the mold contamination situation of the bread after 7 days of storage at 25°C are as Figure 1As shown. From the data in Table 3 and Table 4, it can be seen that after the bread was stored at 25°C for 7 days, compared with after baking, the pH values of each group of samples decreased to varying degrees, and the titratable acidity increased to varying degrees. From the test results, there was no significant difference in the mold count in the bread samples of the postbiotic group 1#, postbiotic group 1-1#, postbiotic group 1-2#, and sodium dehydroacetate group. Among them, the mold count in the postbiotic group 1# sample was significantly lower than that of other groups; the mold and yeast counts in the bread samples of the postbiotic group 1-1# and postbiotic group 1-2# were significantly less than those of the postbiotic group 2#-6# bread samples. The mold count in the bread samples of the postbiotic group 2#-6# was less than that of the blank control group, but significantly higher than that of the postbiotic group 1# and sodium dehydroacetate group samples. Yeast was detected in both the blank control group samples and the bread samples of the postbiotic group 2#-6#, and not detected in the sodium dehydroacetate group and the postbiotic group 1#, 1-1#, 1-2# samples. It shows that the addition of the postbiotic composition 1# can effectively reduce the generation of molds and yeasts, and the addition effect has no significant difference from that of sodium dehydroacetate.

[0139] Sensory evaluation was carried out on the bread after baking and oil return. There were 10 sensory evaluation personnel for each group of samples. The sensory evaluation personnel evaluated the color, shape, and tissue structure of the bread, and carried out sensory characteristic analysis on each sample. The sensory evaluation criteria are shown in Table 5, and the results are shown in Table 6.

[0140] Table 5 Bread sensory evaluation criteria

[0141]

[0142] Table 6 Bread sensory evaluation results

[0143]

[0144] Note: The data in the same column with different subscripts without the same letter indicate the significant difference of the data in the same column (p < 0.05).

[0145] The sensory evaluation results showed that the postbiotic group 1# bread had a moderate and non-irritating sour taste, a strong and pleasant fermentation aroma, no off-flavors, and a good aftertaste. The sensory score was significantly higher than that of the blank control group, sodium dehydroacetate group, and postbiotic group 2#-6# samples. There was no significant difference in the sensory scores of the postbiotic group 1#, 1-1#, and 1-2# bread samples.

[0146] Test Example 3 Experimental verification of anti-corrosion and antibacterial in steamed buns

[0147] The postbiotic composition was applied to steamed bun products to evaluate the storage characteristics of steamed buns. The postbiotic addition amount was 0.3% (calculated based on the solid content). The experiment was divided into 6 groups, namely the blank control group, sodium dehydroacetate group, postbiotic group 1#, postbiotic group 2#, postbiotic group 3#, and postbiotic group 4#. The experimental grouping and formula are shown in Table 7.

[0148] Table 7 Steamed Bun Recipe Table

[0149]

[0150] The pH value and titratable acidity of each batch of steamed buns were measured on the day after production, and each batch of steamed buns was stored at 25°C. The surface bacterial contamination of the steamed buns was observed and recorded every day. On the 7th day of storage, the pH, TA, mold and yeast counts of the steamed buns were measured, and the measurement results are shown in Tables 8 and 9.

[0151] Table 8 Measurement Results of Steamed Bun Index on the Day after Production (n = 3, x±SD)

[0152]

[0153] Note: Data in the same column with the same superscript letter indicate that there is no significant difference in the data of the same column (p > 0.05).

[0154] From the data in Table 8, it can be seen that on the day after production, there was no significant difference in the pH value and titratable acidity of the steamed bun samples in the blank group, sodium dehydroacetate group and postbiotic group.

[0155] Table 9 Measurement Results of Steamed Bun Index after 7 days of storage at 25°C (n = 3, x±SD)

[0156]

[0157] Note: Data in the same column without the same superscript letter indicate the significance of the difference in the data of the same column (p < 0.05).

[0158] The observation and record results of the bacterial contamination of the steamed buns during 7 days of storage are as Figure 2 shown. From the data in Tables 8 and 9, it can be seen that after the steamed buns were stored at 25°C for 7 days, compared with the day after production, the pH values of the samples in each group decreased to varying degrees, and the titratable acidity increased to varying degrees. From the test results, the molds in the steamed bun samples of the postbiotic group and the sodium dehydroacetate group were significantly less than those in the blank group samples. Among them, there was no significant difference in the mold counts in the 1# sample of the postbiotic group and the sodium dehydroacetate group samples. Yeasts were not detected in the sodium dehydroacetate group and the 1# sample of the postbiotic group, and were detected in other postbiotic group and blank control group samples. This indicates that the addition of postbiotic composition 1# can effectively reduce the generation of molds and yeasts, and the addition effect has no significant difference from that of sodium dehydroacetate.

[0159] The above detailed description is a specific description of one of the feasible embodiments of the present invention. This embodiment is not intended to limit the patent scope of the present invention. Any equivalent implementation or modification without departing from the present invention shall be included within the scope of the technical solution of the present invention.

Claims

1. A postbiotic composition for antiseptic and antibacterial properties in food, characterized in that: The raw materials of the postbiotic composition include: inactivated bacteria of composite probiotics and metabolites of composite probiotics; the composite probiotics include Lactobacillus casei Zhang, Bifidobacterium animalis subspecies lactis V9, Lactobacillus plantarum P-8 and Lactobacillus plantarum PB-2; The Lactobacillus casei Zhang is classified and named as Lactobacillus casei, and is deposited in the General Microbiological Center of China Microbiological Culture Collection Administration, with the deposit number of CGMCC No.5469. The animal bifidobacterium lactis subspecies V9 is classified and named as animal bifidobacterium lactis subspecies (Bifidobacteriumanimalis subsp. lactis), and is deposited in the General Microbiological Center of China Microbiological Culture Collection Administration, with a deposit number of CGMCC No.5470; The plant lactobacillus P-8 is classified and named as plant lactobacillus (Lactobacillus plantarum), and is deposited in the General Microbiological Center of China Microbiological Culture Collection Administration, with a deposit number of CGMCC No.6312; The Lactobacillus plantarum PB-2 is classified and named as Lactobacillus plantarum and is deposited in the General Microbiological Center of China Microbiological Culture Collection Administration with a deposit number of CGMCC No.5400. The Lactobacillus casei Zhang, Bifidobacterium animalis lactis subspecies V9, Lactobacillus plantarum P-8 and Lactobacillus plantarum PB-2 are compounded according to the ratio of the number of colony forming units of 1:0.8-1.2:0.8-1.2:1.5-2.5; The preparation method of the postbiotic composition comprises: The composite probiotic strains are inoculated into the sterilized culture medium, and the culture medium is fermented at a constant temperature of 33-37° C. until the pH value reaches 4.5-4.6, and then the culture medium is inactivated and dried to obtain the postbiotic composition.

2. The postbiotic composition according to claim 1, characterized in that Before inactivating the composite probiotics, the total viable count of the composite probiotics is ≥ 5.0 × 10 10 CFU / g.

3. The postbiotic composition according to claim 1, characterized in that The Lactobacillus casei Zhang, Bifidobacterium animalis lactis subspecies V9, Lactobacillus plantarum P-8 and Lactobacillus plantarum PB-2 are compounded in a ratio of 1:1:1:2 in terms of the number of colony forming units.

4. A method for preparing the postbiotic composition according to any one of claims 1 to 3, characterized in that: include: The composite probiotic strains are inoculated into the sterilized culture medium, and the culture medium is fermented at a constant temperature of 33-37° C. until the pH value reaches 4.5-4.6, and then the culture medium is inactivated and dried to obtain the postbiotic composition.

5. Use of the postbiotic composition according to any one of claims 1 to 3 in preparing a product for improving food storage quality.

6. A food, characterized in that The ingredients of the food include the postbiotic composition according to any one of claims 1 to 3.

7. The food according to claim 6, characterized in that In terms of mass percentage, the postbiotic composition is added to the food in an amount of 0.1-1%.

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