Method for inhibiting post-acidification of fermented food and retaining active probiotics

Abstract

The invention provides a method for inhibiting post-acidification of fermented food and retaining active probiotics. Comprising the following steps: fermenting food raw materials to obtain a fermented product; and carrying out induction treatment on the fermented product, so that the probiotics in the fermented product enter a viable and non-culturable state. The method can effectively inhibit post-acidification of the fermented food, prolong the shelf life of the fermented food, reserve the activity of probiotics in the fermented food, maintain or improve the nutritional value of the fermented food and improve the quality of the fermented food, and is wide in application prospect.

Description

[0001] Priority information

[0002] This application claims priority and benefits of patent application 202411545840.6 filed with the State Intellectual Property Office of China on October 31, 2024, and the entire text of which is incorporated herein by reference. Technical Field

[0003] The invention belongs to the technical field of food, and in particular relates to a method for inhibiting post-acidification of fermented food and retaining active probiotics. Background Art

[0004] Fermented food refers to a type of food that is processed and manufactured using beneficial microorganisms. Fermentation can not only enhance the flavor and texture of food, but also increase the nutritional value, digestibility and safety of food, and extend the shelf life. Fermented food contains a large number of active probiotics, which can improve intestinal health, promote digestion, enhance immunity, alleviate allergic symptoms, and have the function of bidirectionally regulating intestinal diseases. Therefore, retaining the probiotics in fermented food is crucial to maintaining its beneficial activity.

[0005] However, the presence of probiotics in fermented foods produces a large amount of lactic acid, causing excessive fermentation, resulting in a decrease in the pH value of the food and an increase in acidity, which not only affects the flavor and texture of the food, but may also shorten its shelf life. The prior art is usually to sterilize the fermented food after fermentation is completed, which results in the death of probiotics, reduced probiotic activity of the product, and reduced product quality.

[0006] Therefore, how to inhibit the post-acidification of fermented foods without damaging the activity of probiotics and at the same time extend their shelf life is a technical problem that urgently needs to be solved in this field. Summary of the invention

[0007] The present invention aims to solve at least one of the technical problems existing in the prior art to a certain extent. To this end, the present invention provides a method for inhibiting post-acidification of fermented food and retaining active probiotics. The method of the present invention has the advantages of effectively inhibiting post-acidification of fermented food, extending the shelf life of fermented food, retaining the activity of probiotics in fermented food, maintaining or improving the nutritional value of fermented food, improving the quality of fermented food, etc., and has broad application prospects.

[0008] In the first aspect of the present invention, the present invention proposes a method for inhibiting post-acidification of fermented foods. According to an embodiment of the present invention, the method comprises: subjecting food raw materials to fermentation treatment to obtain a fermented product; subjecting the fermented product to induction treatment to cause the probiotics in the fermented product to enter a live, uncultivable state. The method according to an embodiment of the present invention can inhibit post-acidification of fermented foods, extend the shelf life of fermented foods, retain the activity of probiotics in fermented foods, maintain or enhance the nutritional value of fermented foods, and improve the quality of fermented foods, and has broad application prospects.

[0009] According to an embodiment of the present invention, the above method may also have the following additional technical features:

[0010] According to an embodiment of the present invention, the induction treatment includes but is not limited to: at least one of ultra-high pressure treatment, high pressure treatment, plasma treatment, pulse electric field treatment, and adverse stress treatment.

[0011] According to an embodiment of the present invention, the probiotics include but are not limited to: Carnobacterium, Enterococcus, Lactobacillus, Lactococcus, Leuconostoc, Oenococcus, Pediococcus, Streptococcus, Streptococcus, Vagococcus, Weissella, Bacillus, Micrococcus, Staphylococcus, Bifidobacterium, Brevibacterium, Corynebacterium, Propionibacterium m), Klebsiella, Haloanaerobium, Halococcus, Pseudomonas, Saccharomyces, Candida, Cryptococcus, Debaryomyces, Dekkera, Geotrichum, Hansenula, Kazachstania, Actinomucor, Amylomyces, Aspergillus, Monascus, Mucor, Nectria, Penicillium, Rhizopus, and Ustilago.

[0012] According to an embodiment of the present invention, the probiotics are Lactobacillus plantarum, and the induction treatment is ultra-high pressure treatment.

[0013] According to an embodiment of the present invention, the pressure of the ultra-high pressure treatment is 200-500 MPa, preferably 200 MPa, the time is 5-20 min, preferably 5 min, and the temperature is 10-25°C, preferably 25°C.

[0014] According to an embodiment of the present invention, the storage temperature of the fermented food is 4°C.

[0015] According to an embodiment of the present invention, before consumption, the fermented food is left to stand at room temperature to revive the probiotics in the fermented food that are in a live, uncultivable state.

[0016] In the second aspect of the present invention, the present invention proposes a method for storing fermented food. According to an embodiment of the present invention, before the fermented food is stored, an induction treatment is first performed to make the probiotics in the fermented food enter a live and uncultivable state. The method according to an embodiment of the present invention can effectively extend the shelf life of the fermented food, retain the activity of the probiotics in the fermented food, maintain or enhance the nutritional value of the fermented food, and improve the quality of the fermented food, and has broad application prospects.

[0017] According to an embodiment of the present invention, the above method may also have the following additional technical features:

[0018] According to an embodiment of the present invention, the induction treatment includes but is not limited to: at least one of ultra-high pressure treatment, high pressure treatment, plasma treatment, pulse electric field treatment, and adverse stress treatment.

[0019] According to an embodiment of the present invention, the probiotics include but are not limited to: at least one of: Carnosaurus, Enterococcus, Lactobacillus, Lactococcus, Leuconostoc, Oenococcus, Pediococcus, Streptococcus, Tetrastreptococcus, Rover, Weissella, Bacillus, Micrococcus, Staphylococcus, Bifidobacterium, Brevibacterium, Brevibacterium, Propionibacterium, Klebsiella, Haloanaerobic Bacteria, Halococcus, Pseudomonas, Brettanomyces, Candida, Cryptococcus, Debaryomyces, Dekkera, Geotrichum, Hansenula, Kazakhstan Saccharomyces, Actinobacillus, Amylomyces, Aspergillus, Monascus, Mucor, Neurospora, Penicillium, Rhizopus, and Ustilago.

[0020] According to a specific embodiment of the present invention, the probiotic is Lactobacillus plantarum, and the induction treatment is ultra-high pressure treatment with a pressure of 200-500 MPa, preferably 400 MPa, a time of 5-20 min, preferably 5 min, and a temperature of 20-40°C, preferably 37°C.

[0021] According to an embodiment of the present invention, the storage temperature of the fermented food is 4°C.

[0022] According to an embodiment of the present invention, before consumption, the fermented food is left to stand at room temperature to revive the probiotics in the fermented food that are in a live, uncultivable state.

[0023] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0025] Figure 1 This is a comparison result of the sugar metabolism of Lactobacillus plantarum CGMCC No.14398 in the stable phase and Lactobacillus plantarum CGMCC No.14398 in the VBNC state in Example 2 of the present invention;

[0026] Figure 2 This is a graph showing the results of measuring the acid production of Lactobacillus plantarum CGMCC No.14398 in the stable phase and in the VBNC state in Example 3 of the present invention;

[0027] Figure 3 It is a graph showing the regrowth curve of Lactobacillus plantarum CGMCC No.14398 in the stable period and the recovery curve of Lactobacillus plantarum CGMCC No.14398 in the VBNC state in Example 3 of the present invention;

[0028] Figure 4 This is a graph showing the pH value measurement results of the storage period of the Lactobacillus plantarum CGMCC No. 14398 in the stable period and the Lactobacillus plantarum CGMCC No. 14398 in the VBNC state after fermentation in Example 4 of the present invention;

[0029] Figure 5 This is a flow chart of inhibiting post-acidification of fermented food and retaining its beneficial activity by regulating the activity of bacterial strains in Example 5 of the present invention. DETAILED DESCRIPTION

[0030] The embodiments of the present invention are described in detail below. The embodiments described below are exemplary and are only used to explain the present invention, and should not be understood as limiting the present invention.

[0031] In this document, the terms “include” or “comprising” are open expressions, that is, including the contents specified in the present invention but not excluding other contents.

[0032] As used herein, the terms "optionally", "optionally" or "optionally" generally mean that the subsequently described event or circumstance may but need not occur, and that the description includes instances where the event or circumstance occurs and instances where it does not.

[0033] Terms and Definitions

[0034] In this article, the term "post-acidification" refers to the phenomenon that during the production process of fermented food, the pH value of the food further decreases due to the continuous metabolic activity of probiotics, which will affect the quality and shelf life of the food to a certain extent.

[0035] In this article, the term "post-acidification time" refers to the time required for the pH value of the fermented food to further decrease until it reaches a stable state due to the continuous metabolic activity of probiotics during the production process of fermented food. The length of the post-acidification time directly affects the quality and shelf life of the fermented food.

[0036] In this article, the term "VBNC" refers to a viable non-culturable state, a special physiological state that microorganisms enter under specific environmental stresses, such as nutrient deficiency, unsuitable temperature, high salt environment, desiccation or heavy metal stress. In this state, although the microorganisms cannot grow and reproduce on conventional culture media, they still maintain a certain metabolic activity and cell integrity, and can resume growth under suitable conditions.

[0037] In this article, the term "room temperature standing treatment" means that before consumption, in order to restore the activity of probiotics in the product, the fermented food needs to be placed at room temperature for a certain period of time. This can allow the probiotics in the VBNC state to gradually recover and restore their original physiological activity and metabolic function without destroying the activity of the probiotics. Among them, "room temperature" usually refers to conditions close to or equal to ambient temperature, generally 18°C ​​to 25°C.

[0038] Method for inhibiting post-acidification of fermented foods

[0039] The present invention proposes a method for inhibiting post-acidification of fermented food. According to an embodiment of the present invention, the method comprises: subjecting food raw materials to fermentation treatment to obtain a fermented product; subjecting the fermented product to induction treatment to cause the probiotics in the fermented product to enter a live, uncultivable state. The method according to an embodiment of the present invention can effectively inhibit post-acidification of fermented food, extend the shelf life of fermented food, retain the activity of probiotics in fermented food, maintain or enhance the nutritional value of fermented food, and improve the quality of fermented food, and has broad application prospects.

[0040] According to an embodiment of the present invention, the induction treatment includes but is not limited to: at least one of ultra-high pressure treatment, high pressure treatment, plasma treatment, pulsed electric field treatment, and adverse stress treatment. The induction treatment has various options, and can be processed by different methods and conditions to make the probiotics enter a live and uncultivable state, which is suitable for a variety of application scenarios.

[0041] According to an embodiment of the present invention, the probiotics include but are not limited to: at least one of Carnosus, Enterococcus, Lactobacillus, Lactococcus, Leuconostoc, Oenococcus, Pediococcus, Streptococcus, Tetrastreptococcus, Rover, Weissella, Bacillus, Micrococcus, Staphylococcus, Bifidobacterium, Brevibacterium, Brevibacterium, Propionibacterium, Klebsiella, Haloanaerobic Bacteria, Halococcus, Pseudomonas, Brettanomyces, Candida, Cryptococcus, Debary's yeast, Dekker's yeast, Geotrichum, Hansen's yeast, Kazakhstan yeast, Actinobacillus, Amylomyces, Aspergillus, Monascus, Mucor, Neurospora, Penicillium, Rhizopus, and Ustilago. The probiotics of the method are rich in varieties and suitable for a variety of application scenarios.

[0042] According to an embodiment of the present invention, the probiotics are Lactobacillus plantarum, and the induction treatment is ultra-high pressure treatment. Thus, the Lactobacillus plantarum in the fermented food is induced to enter a live and uncultivable state through ultra-high pressure treatment, thereby extending the shelf life of the food.

[0043] According to an embodiment of the present invention, the pressure of the ultra-high pressure treatment is 200-500 MPa, preferably 400 MPa, the time is 5-20 min, preferably 5 min, and the temperature is 10-37° C., preferably 37° C. Thus, by ultra-high pressure treatment, probiotics such as Lactobacillus plantarum in fermented food are induced to enter a live and uncultivable state, thereby extending the shelf life of the food.

[0044] Illustratively, the pressure of the ultrahigh pressure treatment is 200 MPa, 250 MPa, 300 MPa, 350 MPa, 400 MPa, 450 MPa, 500 MPa, preferably 400 MPa.

[0045] Exemplarily, the ultrahigh pressure treatment time is 5 min, 6 min, 7 min, 8 min, 9 min, 10 min, 11 min, 12 min, 13 min, 14 min, 15 min, 16 min, 17 min, 18 min, 19 min, 20 min, preferably 5 min.

[0046] Exemplarily, the temperature of the ultra-high pressure treatment is 20°C, 21°C, 22°C, 23°C, 24°C, 25°C, 26°C, 27°C, 28°C, 29°C, 30°C, 31°C, 32°C, 33°C, 34°C, 35°C, 36°C, 37°C, 38°C, 39°C, 40°C, preferably 37°C.

[0047] After a large number of experiments, the inventors determined that the induction effect is better when the ultra-high pressure treatment pressure is 400MPa, the time is 5min, and the temperature is 37°C. Under the ultra-high pressure treatment conditions, Lactobacillus plantarum can be induced to enter a live and uncultivable state, thereby further effectively inhibiting the acidification of Lactobacillus plantarum fermented food, delaying the shelf life of food, and retaining the activity of probiotics.

[0048] According to an embodiment of the present invention, the storage temperature of the fermented food is 4° C. Using low temperature conditions during storage can effectively inhibit the recovery of live uncultivable probiotics in the fermented food and extend the shelf life of the fermented food.

[0049] According to an embodiment of the present invention, the fermented food is placed at room temperature before consumption to revive the probiotics in the fermented food that are in a live but uncultivable state. Thus, the revival of the probiotics in the uncultivable state is promoted, and the probiotic activity of the fermented food is improved.

[0050] How to store fermented foods

[0051] The present invention proposes a method for storing fermented food. According to an embodiment of the present invention, before the fermented food is stored, an induction treatment is first performed to make the probiotics in the fermented food enter a live and uncultivable state. The method according to an embodiment of the present invention can effectively extend the shelf life of the fermented food, retain the activity of the probiotics in the fermented food, maintain or enhance the nutritional value of the fermented food, and improve the quality of the fermented food, and has broad application prospects.

[0052] According to an embodiment of the present invention, the induction treatment includes but is not limited to: at least one of ultra-high pressure treatment, high pressure treatment, plasma treatment, pulsed electric field treatment, and adverse stress treatment. The induction treatment has various options, and can be processed by different methods and conditions to make the probiotics enter a live and uncultivable state, which is suitable for a variety of application scenarios.

[0053] According to an embodiment of the present invention, the probiotics include but are not limited to: at least one of Carnosus, Enterococcus, Lactobacillus, Lactococcus, Leuconostoc, Oenococcus, Pediococcus, Streptococcus, Tetrastreptococcus, Rover, Weissella, Bacillus, Micrococcus, Staphylococcus, Bifidobacterium, Brevibacterium, Brevibacterium, Propionibacterium, Klebsiella, Haloanaerobic Bacteria, Halococcus, Pseudomonas, Brettanomyces, Candida, Cryptococcus, Debary's yeast, Dekker's yeast, Geotrichum, Hansen's yeast, Kazakhstan yeast, Actinobacillus, Amylomyces, Aspergillus, Monascus, Mucor, Neurospora, Penicillium, Rhizopus, and Ustilago. The probiotics of the method are rich in varieties and suitable for a variety of application scenarios.

[0054] According to a specific embodiment of the present invention, the probiotics are Lactobacillus plantarum, and the induction treatment is ultra-high pressure treatment, with a pressure of 200-500 MPa, preferably 400 MPa, a time of 5-20 min, preferably 5 min, and a temperature of 20-40° C., preferably 37° C. Thus, by ultra-high pressure treatment, probiotics such as Lactobacillus plantarum in fermented foods are induced to enter a live, uncultivable state, thereby extending the shelf life of the food.

[0055] Illustratively, the pressure of the ultrahigh pressure treatment is 200 MPa, 250 MPa, 300 MPa, 350 MPa, 400 MPa, 450 MPa, 500 MPa, preferably 400 MPa.

[0056] Exemplarily, the ultrahigh pressure treatment time is 5 min, 6 min, 7 min, 8 min, 9 min, 10 min, 11 min, 12 min, 13 min, 14 min, 15 min, 16 min, 17 min, 18 min, 19 min, 20 min, preferably 5 min.

[0057] Exemplarily, the temperature of the ultra-high pressure treatment is 20°C, 21°C, 22°C, 23°C, 24°C, 25°C, 26°C, 27°C, 28°C, 29°C, 30°C, 31°C, 32°C, 33°C, 34°C, 35°C, 36°C, 37°C, 38°C, 39°C, 40°C, preferably 37°C.

[0058] After a large number of experiments, the inventors determined that the induction effect is better when the ultra-high pressure treatment pressure is 400MPa, the time is 5min, and the temperature is 37°C. Under the ultra-high pressure treatment conditions, plant lactobacillus can be induced to enter a live and uncultivable state, thereby allowing the treated probiotics to better maintain their activity during storage, improve storage efficiency, further effectively inhibit post-acidification of fermented foods, delay food shelf life, retain probiotic activity, and improve the quality of fermented foods.

[0059] According to an embodiment of the present invention, the storage temperature of the fermented food is 4° C. Thus, by storing the fermented food at a low temperature of 4° C., the activity of the probiotics in a live, uncultivable state is further maintained, the shelf life of the fermented food is further extended, and the freshness and nutritional value of the food are ensured.

[0060] According to an embodiment of the present invention, the fermented food is left to stand at room temperature before consumption to revive the probiotics in the fermented food that are in a live, uncultivable state. Thus, the probiotics in the fermented food are restored to their activity, ensuring that consumers can obtain the health benefits of the probiotics contained in the fermented food to a high degree.

[0061] Unless otherwise specified, the Lactobacillus plantarum (formerly known as Lactobacillus plantarum) used in the embodiments of the present invention is a strain with a deposit number of CGMCC No. 14398, and is referred to as Lactobacillus plantarum CGMCC No. 14398 in the embodiments of the present invention.

[0062] The scheme of the present invention will be explained below in conjunction with the embodiments. It will be appreciated by those skilled in the art that the following embodiments are only used to illustrate the present invention and should not be considered as limiting the scope of the present invention. Where specific techniques or conditions are not indicated in the embodiments, the techniques or conditions described in the literature in this area or the product specifications are used. The reagents or instruments used are not indicated by the manufacturer and are all conventional products that can be obtained commercially.

[0063] Example 1: Induction of VBNC state of Lactobacillus plantarum CGMCC No.14398

[0064] The inventors induced Lactobacillus plantarum CGMCC No.14398 to enter a viable non-culturable (VBNC) state, and the specific steps are as follows:

[0065] (1) Preparation of bacterial suspension

[0066] The plant lactobacillus CGMCC No.14398 in the logarithmic growth phase was cultured to the stable phase, centrifuged at 6000×g and washed twice with a 0.85% by mass NaCl aqueous solution, and then the cells were resuspended with a 0.85% by mass NaCl aqueous solution or PBS to obtain a plant lactobacillus liquid in the stable phase, with a cell concentration of about 10 8 cfu / ml.

[0067] (2) Ultrahigh pressure treatment

[0068] Ultrahigh pressure treatment was used to induce Lactobacillus plantarum CGMCC No.14398 to enter the VNBC state. The resuspended Lactobacillus plantarum bacterial solution in the stable period was placed in a plastic bag, and the plastic bag was placed in the Suyuan Zhongtian CQC-600 ultrahigh pressure treatment chamber. The temperature was 37°C and the pressure was 400MPa for 5 minutes. After reaching the above parameters, the pressure was immediately released to obtain the Lactobacillus plantarum CGMCC No.14398 (400MPa) bacterial solution in the VBNC state, and the bacterial concentration was about 10 8 cfu / ml; take the above resuspended plant lactobacillus bacterial solution in the stable period, put it into a plastic bag, put the plastic bag into the Suyuan Zhongtian CQC-600 ultra-high pressure treatment chamber, treat it for 5 minutes at a temperature of 37°C and a pressure of 500MPa, and immediately release the pressure after reaching the above parameters to obtain a plant lactobacillus CGMCC No.14398 (500MPa) bacterial solution in the VBNC state, with a bacterial concentration of about 10 8 cfu / ml.

[0069] Example 2: Finding that the sugar metabolism of Lactobacillus plantarum CGMCC No.14398 is reduced in the VBNC state

[0070] The inventors investigated the sugar metabolism activity levels of Lactobacillus plantarum CGMCC No. 14398 in the stable period, Lactobacillus plantarum CGMCC No. 14398 (400 MPa) in the VBNC state, and Lactobacillus plantarum CGMCC No. 14398 (500 MPa) in the VBNC state. The investigation method is as follows:

[0071] Take 10 mL of each of the plant lactobacillus CGMCC No.14398 bacterial solution in the stable phase, the plant lactobacillus CGMCC No.14398 (400 MPa) bacterial solution in the VBNC state, and the plant lactobacillus CGMCC No.14398 (500 MPa) bacterial solution in the VBNC state obtained in Example 1, and the bacterial cell concentration is about 10 8 CFU / mL, and stored at 4°C for 30 days. The reducing sugar content in the fermentation broth was determined and recorded every 3 days using a reducing sugar detection kit (Shanghai Yuanye Biotechnology, product number: R26241-50T).

[0072] The results of the comparison of sugar metabolism between stable Lactobacillus plantarum CGMCC No.14398 and VBNC state Lactobacillus plantarum CGMCC No.14398 are shown in Figure 1 .

[0073] The results showed that when stored at 4°C after fermentation, the stable Lactobacillus plantarum CGMCC No.14398 consumed 2 mg / mL of reducing sugar in 30 days; while the VBNC state Lactobacillus plantarum CGMCC No.14398 (500MPa) and Lactobacillus plantarum CGMCC No.14398 (500MPa) obtained by ultra-high pressure induction at 400MPa and 500MPa only consumed 1.5 and 0.5 mg / mL, respectively, in 30 days; that is, under the same number of live bacteria, the reducing sugar consumption of Lactobacillus plantarum CGMCC No.14398 in the VBNC state was significantly lower than that of Lactobacillus plantarum CGMCC No.14398 in the stable period.

[0074] The above results indicate that compared with Lactobacillus plantarum CGMCC No.14398 in the stable period, Lactobacillus plantarum CGMCC No.14398 in the VBNC state consumes less sugar.

[0075] Based on this, the inventors hypothesized that under the VBNC state, the respiration of microorganisms is reduced and the acid production is reduced.

[0076] Example 3: Determination of acid production and recovery curve of Lactobacillus plantarum CGMCC No.14398 under VBNC state

[0077] To verify the hypothesis proposed in the above Example 2, the inventors detected the acid production of Lactobacillus plantarum CGMCC No.14398 during storage at 4°C in the stable period and VBNC state. The specific inspection method is as follows:

[0078] (1) Determination of acid production

[0079] Take 100 mL of each of the bacterial solutions of Lactobacillus plantarum CGMCC No.14398 in the stable period, Lactobacillus plantarum CGMCC No.14398 in the VBNC state (400 MPa), and Lactobacillus plantarum CGMCC No.14398 in the VBNC state (500 MPa), with a bacterial concentration of about 10 8 The fermented broth was stored at 4°C for 30 days, and the acid production in the fermented broth was measured with 5 mL of the broth every 3 days and recorded.

[0080] (2) Establishment of the recovery curve

[0081] Every 3 hours, 1 mL of bacterial solution of Lactobacillus plantarum CGMCC No.14398 in the stable period during storage at 4°C, 1 mL of Lactobacillus plantarum CGMCC No.14398 (400 MPa) in the VBNC state, and 1 mL of Lactobacillus plantarum CGMCC No.14398 (500 MPa) in the VBNC state were taken for plate counting to detect the number of culturable bacteria, and a recovery curve was drawn based on the counting results.

[0082] The results of the determination of acid production of Lactobacillus plantarum CGMCC No.14398 in the stable period and VBNC state are shown in Figure 2 .

[0083] The regrowth curve of Lactobacillus plantarum CGMCC No.14398 in the stable period and the recovery curve of Lactobacillus plantarum CGMCC No.14398 in the VBNC state are shown in Figure 3 .

[0084] The results showed that Lactobacillus plantarum CGMCC No.14398 in the stable period produced lactic acid all the time during storage, while Lactobacillus plantarum CGMCC No.14398 in the VBNC state began to produce lactic acid after 21 days of storage, and Lactobacillus plantarum CGMCC No.14398 in the VBNC state could gradually recover and regain activity when the environment was suitable.

[0085] Example 4: Determination of pH value during storage after fermentation of Lactobacillus plantarum CGMCC No.14398 under VNBC condition

[0086] To further verify the hypothesis proposed in the above Example 2, the inventors tested the pH value of the fermentation storage period of Lactobacillus plantarum CGMCC No.14398 during storage at 4°C in the stable period and VBNC state. The inspection method is as follows:

[0087] Take 50 mL of each of the stable phase Lactobacillus plantarum CGMCC No.14398 bacterial solution, VBNC state Lactobacillus plantarum CGMCC No.14398 (400 MPa) bacterial solution and VBNC state Lactobacillus plantarum CGMCC No.14398 (500 MPa) bacterial solution, the bacterial concentration of which is about 10 8 CFU / mL, stored at 4°C for 30 days, and the pH value of the fermentation broth was measured and recorded every 3 days using a pH meter (METTLERTOLEDO, Switzerland) in accordance with the national standard GB 5009.237-2016.

[0088] The results of pH value determination during storage after fermentation of Lactobacillus plantarum in the stable period and VBNC state are shown in Figure 4 .

[0089] The results showed that when stored at 4°C after fermentation, the pH value of Lactobacillus plantarum in the stable period dropped to 4.75 in 6 days, while the pH value of Lactobacillus plantarum in the VBNC state dropped to 4.75 after 27 days. That is, under the same number of live bacteria, the pH decrease rate of Lactobacillus plantarum in the VBNC state was significantly lower than that of Lactobacillus plantarum in the stable period.

[0090] Example 5: Proposal for a process design to inhibit post-acidification of fermented food and retain its beneficial activity by regulating bacterial activity

[0091] The experimental results of Examples 2 to 4 show that the acid production of Lactobacillus plantarum CGMCC No. 14398 is lower in the VBNC state, which can effectively inhibit the post-acidification of fermented food.

[0092] Therefore, the inventors proposed that if after the fermentation of food is completed, the probiotics in it are induced to enter the VBNC state and their metabolic activity is reduced while ensuring the survival of the probiotics, it is theoretically possible to effectively inhibit the post-acidification of the product; and during the storage process, low temperature (<8°C) can be used to inhibit the recovery of probiotics in the VBNC state, thereby extending its shelf life; before consuming fermented food, it can be left at room temperature for more than 2 hours to allow the probiotics in the VBNC state to recover and improve the probiotic activity of the product.

[0093] Therefore, the inventor proposes the following process design:

[0094] Food raw materials → inoculation or natural fermentation → fermentation completed → induce probiotics to enter VBNC state and then acidify → transport and store at low temperature to inhibit the recovery of probiotics in VBNC state → stand at room temperature before consumption to induce the recovery of probiotics in VBNC state → consume

[0095] Among them, the methods for inducing probiotics to enter the VBNC state after the product fermentation is completed include: non-thermal processing of food, such as ultra-high pressure, high-pressure carbon dioxide, plasma, pulsed electric field treatment, etc.; other adversities, such as oxidative stress, hyperosmotic stress treatment, etc.

[0096] The process of inhibiting the post-acidification of fermented food and retaining its beneficial activity by regulating the activity of bacterial strains is shown in Figure 5 .

[0097] Fermented foods processed through this process can effectively inhibit post-acidification of fermented foods, extend the shelf life of fermented foods, and retain the activity of probiotics in fermented foods.

[0098] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A method for inhibiting post-acidification of fermented food, characterized in that: include: Fermenting the food raw materials to obtain fermented products; The fermented product is subjected to an induction treatment so that the probiotics in the fermented product enter a live and uncultivable state.

2. The method according to claim 1, characterized in that The induction treatment includes but is not limited to: at least one of ultra-high pressure treatment, high pressure treatment, plasma treatment, pulse electric field treatment, and adverse stress treatment.

3. The method according to claim 1, characterized in that The probiotics include but are not limited to: At least one of the genera Carnosus, Enterococcus, Lactobacillus, Lactococcus, Leuconostoc, Oenococcus, Pediococcus, Streptococcus, Tetrastreptococcus, Rover, Weissella, Bacillus, Micrococcus, Staphylococcus, Bifidobacterium, Brevibacterium, Brevibacterium, Propionibacterium, Klebsiella, Haloanaerobic Bacteria, Halococcus, Pseudomonas, Brettanomyces, Candida, Cryptococcus, Debaryomyces, Dekkera, Geotrichum, Hansenula, Kazakhstan Saccharomyces, Actinobacillus, Amyloliquefaciens, Aspergillus, Monascus, Mucor, Neurospora, Penicillium, Rhizopus, and Ustilago.

4. The method according to claim 3, characterized in that The probiotics are Lactobacillus plantarum, and the induction treatment is ultra-high pressure treatment.

5. The method according to claim 4, characterized in that The ultra-high pressure treatment is performed at a pressure of 200-500 MPa, preferably 400 MPa, for a time of 5-20 min, preferably 5 min, and at a temperature of 20-40° C., preferably 37° C.

6. The method according to claim 1, characterized in that The storage temperature of the fermented food is 4°C.

7. The method according to claim 6, characterized in that Before eating, the fermented food is left to stand at room temperature to revive the probiotics in the fermented food that are in a live but uncultivable state.

8. A method for storing fermented food, characterized in that: Before the fermented food is stored, an induction treatment is first performed to make the probiotics in the fermented food enter a live and uncultivable state.

9. The method according to claim 8, characterized in that The induction treatment includes but is not limited to: at least one of ultra-high pressure treatment, high pressure treatment, plasma treatment, pulse electric field treatment, and adverse stress treatment.

10. The method according to claim 8, characterized in that The probiotics include but are not limited to: At least one of the genus Carnosus, Enterococcus, Lactobacillus, Lactococcus, Leuconostoc, Oenococcus, Pediococcus, Streptococcus, Tetrastreptococcus, Rover, Weissella, Bacillus, Micrococcus, Staphylococcus, Bifidobacterium, Brevibacterium, Brevibacterium, Propionibacterium, Klebsiella, Haloanaerobic Bacteria, Halococcus, Pseudomonas, Brettanomyces, Candida, Cryptococcus, Debaryomyces, Dekkera, Geotrichum, Hansenula, Kazakhstan Saccharomyces, Actinobacillus, Amyloliquefaciens, Aspergillus, Monascus, Mucor, Neurospora, Penicillium, Rhizopus, and Ustilago; Optionally, the probiotic is Lactobacillus plantarum, and the induction treatment is ultra-high pressure treatment, with a pressure of 200-500 MPa, preferably 400 MPa, a time of 5-20 min, preferably 5 min, and a temperature of 20-40° C., preferably 37° C.

11. The method according to claim 8, characterized in that The storage temperature of the fermented food is 4°C.

12. The method according to claim 8, characterized in that Before eating, the fermented food is left to stand at room temperature to revive the probiotics in the fermented food that are in a live but uncultivable state.

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