Low-sodium salt-reducing freshness-increasing metagen as well as preparation method and application of low-sodium salt-reducing freshness-increasing metagen

Abstract

The invention belongs to the technical field of biological medicines, and particularly discloses a low-sodium salt-reducing freshness-increasing metagen as well as a preparation method and application thereof. The low-sodium, salt-reducing and freshness-increasing after-generation element disclosed by the invention comprises an inactivated thallus of the Lactobacillus paracasei Probio-37 and a metabolite of the Lactobacillus paracasei Probio-37, and the metabolite of the Lactobacillus paracasei Probio-37 can be used for preparing the low-sodium, salt-reducing and freshness-increasing after-generation element of the Lactobacillus paracasei Probio-37. The preparation method of the metagen comprises the following steps: (1) activating a strain, and carrying out enlarged culture to obtain a seed solution of the lactobacillus paracasei Probio-37; (2) inoculating the seed solution in the step (1) into a fermentation culture medium, carrying out fermentation culture until the pH value is 4.5-4.6, and stopping fermentation to obtain a fermentation solution; (3) inactivating the fermentation liquor in the step (2); and (4) carrying out decoloration, concentration and spray drying on the inactivated fermentation liquor to obtain the metabiotics. According to the snack prepared from the afterbiotics, the effects of reducing salt without reducing freshness and reducing sodium without reducing saltiness are achieved, the taste and smell of the snack can be improved, and the scientific salt reducing target of reducing sodium without reducing saltiness is achieved.

Description

Technical Field

[0001] The present invention belongs to the technical field of biomedicine, and specifically relates to a low-sodium, salt-reducing, and freshness-enhancing postbiotic, and a preparation method and application thereof. Background Art

[0002] Postbiotics refer to preparations of inanimate microorganisms and / or their components that are beneficial to the health of the host. Postbiotics are artificially inactivated microbial cells. Metabolites or cell components that have been proven to be beneficial to health may or may not be added. According to classification, postbiotics mainly include two major categories of substances: metabolites and bacterial components. Metabolites include: organic acids, short-chain fatty acids, intracellular polysaccharides, vitamins, proteins, enzymes, and lipids; bacterial components include: lipoteichoic acid, teichoic acid, peptidoglycan, cell surface proteins, polysaccharides, cell membrane proteins, and extracellular polysaccharides. Postbiotics are more convenient to transport and store than probiotic powders. The use of postbiotics can achieve similar prebiotic effects to probiotics while avoiding the problems of narrow application industries of live bacteria themselves, low bioavailability, unstable effects, and easy transmission of drug-resistant genes. Therefore, postbiotics are now widely used in health foods, food processing and other industries.

[0003] Lactobacillus paracasei is closely related to the lives of humans and animals. It is a lactic acid bacterium commonly found in cream, meat, many vegetables, fermented products and feeds. It can play a beneficial role in the intestines. At present, the application fields reported by the research include food, feed, medical care, cosmetics, beauty, aquaculture, probiotic preparations, etc. When a sufficient number of bacteria are consumed, it may bring certain health benefits to the host. Prior art CN117179212B discloses a postbiotic composition for improving the storage quality of food, the components of the postbiotic composition include inactivated bacteria and / or metabolites of the probiotic composition, the components of the probiotic composition include Lactobacillus paracasei ProSci-101 and Lactobacillus fermentum ProSci-602, and the postbiotic composition can effectively improve the storage quality of meat products such as cooked sausages. Prior art CN115886230B discloses a low-sodium, salt-reducing, and flavor-enhancing plant protein peptide, and its preparation method and application. It uses plant protein rich in amides as raw material, and uses exoenzymes and glutaminase to hydrolyze the plant protein step by step after endoenzyme hydrolysis, so that the hydrolyzate is debittered and free amides are converted to obtain a umami-enhanced plant protein peptide. In order to achieve the goal of "scientific salt reduction" of "reducing sodium without reducing saltiness", it is necessary to develop new postbiotic compositions or protein peptides. Summary of the invention

[0004] In order to solve the above problems, the present invention provides a low-sodium, salt-reducing and freshness-enhancing postbiotic and a preparation method and application thereof. The specific technical scheme is as follows: In a first aspect, the present invention provides a low-sodium, salt-reducing and freshness-enhancing postbiotic, the postbiotic comprising Lactobacillus paracasei ( Lacticaseibacillus paracasei ) The inactivated bacteria of Probio-37 and the metabolites of Lactobacillus paracasei Probio-37.

[0005] Among them, the Lactobacillus paracasei Probio-37 has been publicly deposited in CN111575211B.

[0006] Specifically, the viable count of the inactivated bacteria of Lactobacillus paracasei Probio-37 is ≥ 1.86×10 11 CFU / g.

[0007] Specifically, the metabolites of Lactobacillus paracasei Probio-37 include flavor active compounds, flavor peptides and flavor amino acids.

[0008] In further detail, the aroma-active compound includes one or more of ketones, aldehydes, acids, alcohols, furans, pyrazines, thiazoles and terpenes.

[0009] In some embodiments, ketone aroma actives such as 1-hydroxy-2-propanone and 4-hydroxy-2,5-dimethyl-3(2H)-furanone provide roasted aroma, pyrazine aroma actives such as trimethylpyrazine provide nutty flavor, furan aroma actives such as 2-methyl-5-methylthiofuran provide meaty flavor, and aldehyde aroma actives such as 3-methylthiopropionaldehyde provide boiled potato flavor.

[0010] In some embodiments, the total content of the flavor amino acids is ≥ 2220 mg / L, and the content of umami amino acids in the flavor amino acids is ≥ 1370 mg / L.

[0011] Specifically, the flavor peptides include one or more of umami peptides, kokumi peptides, salty peptides and umami amino acids.

[0012] More specifically, the umami peptide includes one or more of Gln-Leu, Pro-Glu-Thr, Ala-Pro-Ala and His-Val.

[0013] More specifically, the salty peptide includes one or more of Asp-Asp, Glu-Asp, Asp-Asp-Asp, Ser-Pro-Glu and Phe-Ile.

[0014] In a second aspect, the present invention provides a method for preparing postbiotics, comprising the following steps: (1) activating the strain and expanding the culture to obtain the seed solution of Lactobacillus paracasei Probio-37; (2) inoculating the seed solution in step (1) into a fermentation medium, fermenting and culturing until the pH reaches 4.5-4.7, and stopping the fermentation to obtain a fermentation liquid; (3) inactivating the fermentation broth in step (2); (4) The inactivated fermentation broth is decolorized, concentrated and spray-dried to obtain postbiotics.

[0015] The liquid culture medium for activating the bacterial strain in step (1) comprises: 10.0 g / L peptone, 5.0 g / L beef extract, 20.0 g / L glucose, 4.0 g / L yeast powder, 1.0 g / L Tween-80, 2.0 g / L K2HPO4·7H2O, 1.0 g / L KH2PO4·7H2O, 5.0 g / L anhydrous sodium acetate, 2.0 g / L triammonium citrate, 0.2 g / L MgSO4·7H2O, and 0.04 g / L MnSO4·H2O. The prepared culture medium is sterilized at 121°C for 15 minutes.

[0016] Specifically, the inoculation amount of the seed liquid in step (2) is 1%-5%, and the fermentation temperature is 35°C-39°C.

[0017] The inoculation amount refers to the ratio of the volume of the seed solution transferred in to the volume of the culture solution after inoculation, and the percentage of the inoculation amount here refers to the volume fraction.

[0018] Specifically, the components of the fermentation medium in step (2) include: 1% defatted soy flour, 8% defatted milk powder and water.

[0019] The percentages of fermentation medium components refer to mass fractions.

[0020] Specifically, the process includes mixing the components of the fermentation medium according to 1% defatted soy flour, 8% skimmed milk powder and 91% water, and then stirring the mixture at 58° C. (i.e., stirring at 150 rpm) for 15 minutes to obtain a liquid feed; homogenizing the liquid feed once at 58° C. at a primary pressure of 19 MPa and a secondary pressure of 5.0 MPa to obtain a homogenized liquid feed; sterilizing the homogenized liquid feed at 93° C. for 30 minutes to obtain a sterilized liquid feed; and cooling the sterilized liquid feed to 35° C. to obtain a fermentation medium.

[0021] Specifically, the inactivation method in step (3) is selected from any one of thermal inactivation, chemical inactivation and biological inactivation.

[0022] In some embodiments, the inactivation is performed by heat inactivation.

[0023] Specifically, the decolorization in step (4) uses a nanofiltration membrane with a membrane molecular weight of 200-300Da.

[0024] Specifically, the concentration conditions in step (4) include: vacuum degree ≥ -0.07 MPa, temperature 65-75° C., and solid content of the inactivated fermentation broth reaching 55-65%.

[0025] In a third aspect, the present invention provides a use of the aforementioned postbiotic or the postbiotic prepared by the aforementioned preparation method in preparing food.

[0026] Specifically, the food includes one or more of convenience food, biscuits, potatoes, puffed food, sauces, roasted food, nut products and meat products.

[0027] In a fourth aspect, the present invention provides potato chips, comprising the above-mentioned postbiotics, and baking according to conventional operations to prepare potato chips.

[0028] Compared with the prior art, the beneficial effects of this application are embodied in: The potato chips made by the present invention using low-sodium, salt-reduced, and fresh-enhanced postbiotics have a sodium content reduced by 28.8% when 5% of postbiotics are added compared to the full-salt solution. The potato chips made by this technical solution have no significant effect on their state, texture, crispness, and flavor, and can give the product better umami and flavor while reducing the sodium content. Adding low-sodium, salt-reduced, and fresh-enhanced postbiotic products can remove chemical food additives, and can give the product a healthier concept while cleaning the label. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is the secondary mass spectrum of Glu-Ser; Figure 2 is the secondary mass spectrum of Asp-Glu-Thr; Figure 3 is the secondary mass spectrum of Ala-Leu-Ala; Figure 4 is the secondary mass spectrum of Glu-Gly; Figure 5 is the secondary mass spectrum of Asp-Asp; Figure 6 is the secondary mass spectrum of Glu-Asp; Figure 7 is the secondary mass spectrum of Asp-Asp-Asp; Figure 8 is the secondary mass spectrum of Ser-Glu; Fig. 9 Radar chart of sensory evaluation of potato chips made with added postbiotics; Fig.10 Comparison of the appearance of potato chips made for the four groups; Fig.11 A is the result of the electronic nose measurement of potato chips, and B is the result of the electronic tongue measurement of potato chips; Fig.12 The results of bacterial count determination in potato chips made from 4 groups. DETAILED DESCRIPTION

[0030] The present invention will be further described in detail below in conjunction with specific examples. The following examples are not intended to limit the present invention, but are only intended to illustrate the present invention. The experimental methods used in the following examples are generally conventional, unless otherwise specified, and the materials, reagents, etc. used in the following examples are commercially available, unless otherwise specified.

[0031] Experimental reagents / instruments: Lactobacillus paracasei Probio-37 (from naturally fermented acid whey in Yunnan), high performance liquid chromatography (purchased from Agilent, USA, model 1260), ultra high performance liquid chromatography (ACQUITY UPLC, purchased from Waters, USA), ion mass spectrometry (purchased from Agilent, USA), crystal violet solution (purchased from Beijing Biolab Technology Co., Ltd.).

[0032] Example 1 A low-sodium, salt-reducing, freshness-enhancing postbiotic 1. Preparation method The single colony in the experiment was Lactobacillus paracasei ( Lacticaseibacillus paracasei ) Probio-37, the specific steps are as follows: (1) Activate the strains and prepare the seed solution: Under sterile conditions, inoculate the activated single colony into the liquid culture medium with an inoculation loop and culture at 37°C for 8-10 hours to obtain the first-level seed solution; Under sterile conditions, inoculate the first-level seed solution into the liquid culture medium at an inoculum rate of 2%, and culture at 37°C for 8-10 hours to obtain the second-level seed solution; Under sterile conditions, the secondary seed solution was inoculated into the liquid culture medium at an inoculation rate of 3%, and cultured at 37°C for 8-10 hours to obtain the tertiary seed solution, and the stirring speed was controlled at 50-70 rpm; (2) Fermentation with Lactobacillus paracasei Probio-37: The third-grade seed liquid activated in step (1) was transferred to the fermentation medium at an inoculum rate of 3% and stirred for 8 minutes. The mixture was fermented at 37°C for 26 hours until the pH of the fermentation liquid reached 4.55. The fermentation was stopped and heat-inactivated at 115-120°C for 10 minutes.

[0033] The fermentation medium comprises 1% defatted soy flour, 8% defatted milk powder and water. Specifically, the fermentation medium is mixed in proportion, and then stirred at 58°C (i.e. stirred at 150 rpm) for 15 minutes to obtain a feed liquid; the feed liquid is homogenized once at 58°C, at a primary pressure of 19 MPa and a secondary pressure of 5.0 MPa to obtain a homogenized feed liquid; the homogenized feed liquid is sterilized at 93°C for 30 minutes to obtain a sterilized feed liquid; and the sterilized feed liquid is cooled to 35°C to obtain a fermentation medium.

[0034] (3) Decolorization and concentration: The fermentation liquid inactivated in step (2) is cooled to below 44°C, decolorized and pre-concentrated using a nanofiltration membrane with a molecular weight of 200-300Da. When the solid content of the inactivated fermentation liquid reaches 35-45%, the pre-concentration is completed, and the liquid is transferred to double-effect vacuum concentration, with a vacuum degree of ≥ -0.07MPa and a temperature of 65-75°C. When the solid content of the inactivated fermentation liquid reaches 55-65%, the concentration is stopped, and the pH of the concentrate is adjusted to 4.5-4.8 (using sterilized calcium hydroxide) for standby use.

[0035] (4) Powder preparation: The air inlet temperature is automatically controlled between 120-150°C, and the air outlet temperature is automatically controlled between 55-75°C for spray drying. The spray-dried postbiotic powder is screened by 80-100 mesh rotary oscillation, and the screened postbiotic powder is filled in a stainless steel storage tank. The material on the sieve that cannot pass through the rotary oscillation screen is crushed by a pulverizer and then loaded into the storage tank.

[0036] (5) Packaging inspection: The postbiotic powder obtained in step (4) is automatically weighed, heat-sealed, and sealed after coding at 1 kg per bag and transported to the finished product temporary storage room for sampling and testing. The postbiotic powder has a white or light yellow appearance, no foreign matter, no odor, and a viable bacterial count of ≥1.0×10 11 CFU / g, no precipitation in dispersibility dissolution test, moisture content <5%.

[0037] 2. Detection of metabolites and bacterial counts in postbiotics 2.1 Detection of aroma-active compounds Weigh 8g of postbiotics and put them into a solid phase microextraction vial; add 1μL of 1.68μg / μL 2-methyl-3-heptanone solution as an internal standard and seal it; equilibrate in a 50℃ water bath for 20min; then insert the solid phase microextraction needle into the vial and push the handle to keep the fiber head in the headspace state for adsorption for 40min.

[0038] The column was a DB-WAX capillary column (30 m × 0.25 mm, 0.25 μm); the carrier gas was helium (purity > 99.99%); the constant flow rate was 1.2 mL / min, and the split ratio was 10:1; the injection port temperature was 250 °C; and the column box heating program was as follows: initial temperature 40 °C, maintained for 3 min, heated to 200 °C at 5 °C / min, maintained for 0 min, and then heated to 260 °C at 15 °C / min, maintained for 3 min.

[0039] The measurement results are shown in Table 1. 2-Methyl-5-methylthiofuran has the highest mass concentration and mainly provides meaty flavor, 1-hydroxy-2-propanone and 4-hydroxy-2,5-dimethyl-3(2H)-furanone provide roasted aroma, trimethylpyrazine provides nutty flavor, and 3-methylthiopropionaldehyde provides boiled potato flavor. These aroma-active compounds are important factors in forming the overall aroma of postbiotics.

[0040] Table 1 Detection results of aroma active compounds in low sodium, salt-reduced and fresh-enhanced postbiotics

[0041] 2.2 Determination of flavor amino acids Pipette an appropriate amount of the postbiotics of Example 1 into an EP tube (2 mL), add 600 μL of 10% formic acid methanol solution-H2O (1:1, V / V) solution, vortex oscillate for 30 s, centrifuge at 12000 rpm and 4°C for 5 min, take 10 μL of the supernatant, add 990 μL of 10% formic acid methanol solution-H2O (1:1, V / V) solution, vortex oscillate for 30 s, take 100 μL of the diluted sample, add 100 μL of a dual isotope internal standard with a concentration of 100 ppb, vortex oscillate for 30 s, filter the supernatant through a 0.22 μm membrane, and add the filtrate to a detection bottle for chromatograph detection.

[0042] The test results are shown in Table 2. The content of flavor-related amino acids in low-sodium, salt-reduced, and fresh-enhanced postbiotics reached 2213.49 mg / L. The content of umami amino acids in low-sodium, salt-reduced, and fresh-enhanced postbiotics is higher, so the umami taste is stronger. UF, GPC, and HPLC-Q-TOF technologies were used to separate and purify umami peptides, and four umami peptide segments, including Glu-Ser, Asp-Glu-Thr, Ala-Leu-Ala, and Glu-Gly, were identified, which contributed greatly to improving its taste characteristics.

[0043] Table 2 Free amino acid content in low sodium, salt-reduced and fresh-enhanced postbiotics

[0044] 2.3 Determination of salty peptides The distribution of peptides in low-sodium and salt-reduced postbiotics was analyzed using a high-performance liquid chromatography (Agilent 1260 II) equipped with a TSKgel column (G2000 SWXL, 300mm×7.8mm, 5μm). 2mg / mL of aprotinin (Mr=6512Da), vitamin B12 (Mr=1355Da), glycine-tyrosine-arginine (Mr=451Da), glutathione (Mr=307Da), and glycine (Mr=75Da) were used as standard samples to draw a standard curve for the external standard method to analyze the distribution of peptides in low-sodium and salt-reduced postbiotics, where the horizontal axis is the retention time and the vertical axis is the logarithm of the relative molecular mass of the peptide standard (lg Mw). The molecular weight distribution range of the peptide can be obtained through the standard curve.

[0045] Table 3 shows the distribution of peptides in low-sodium, salt-reduced and fresh-enhanced postbiotics. It can be seen that peptides with a molecular weight of <1000 Da account for the highest proportion, reaching 71.8%. Some studies have proved that the 300-2000 Da distribution peptide segment has a certain contribution to the rich taste by analyzing the correlation of non-volatile matter.

[0046] Table 3 Distribution percentage of polypeptides in low sodium, salt-reducing and fresh-enhancing postbiotics

[0047] The above postbiotic components were diluted with a certain amount of ultrapure water, and the peptide sequences of salty peptides were separated and identified by Agilent 6530 UPLC-Q-TOF MS / MS using an Eclipse Plus C18 RRHD (2.1 mm×50 mm, 1.8 μm) high-efficiency separation column. Methanol and ultrapure water were used as mobile phases, with a flow rate of 0.2 mL / min, an injection volume of 2 μL, and a column temperature of 35°C. The elution program was methanol 3%-20%, 0-20 min, and held for 1 min; methanol 80%-100%, 21-30 min; methanol 100%-5%, 30-32 min.

[0048] The mass spectrometry conditions are as follows: Ion source: ESI positive ion mode; capillary voltage: 3500 V; nozzle voltage: 500 V; atomization pressure: 35 psig, dryer temperature: 300°C; flow rate: 5 L / min; carrier gas: N2; temperature: 150°C; flow rate: 1 L / min; flow rate: 0.2 mL / min; fragmentor voltage: 135 V; collision energy: 100, 110, 120, 300 eV; ion scan range: 50-1000 m / z.

[0049] like Figure 1-8The test results showed that a total of 4 salty peptides were detected in postbiotics, including 3 dipeptides and 1 tripeptide. The amino acid sequences were Asp-Asp, Glu-Asp, Ser-Glu, and Asp-Asp-Asp, and the abundance of these four salty peptides in postbiotics was quite high.

[0050] 2.4 Determination of postbiotic bacterial count Weigh 1.0g of postbiotic sample and dissolve it in 9mL of sterile 0.1% tween80 PBS buffer solution, and shake to mix evenly; take out 1mL of the diluted bacterial solution in a 2mL EP tube, centrifuge at 12000rpm for 8 minutes, collect the bacterial precipitate and add 1mL of 0.1% tween80 PBS, shake to mix evenly; add 1mL of 2% crystal violet solution, shake to mix evenly, and let it stand at room temperature for staining for 8-10 minutes; after staining, centrifuge at 13000 rpm for 3 minutes, remove the supernatant, and dissolve it back in 0.2% tween 80 PBS. Shake to mix evenly.

[0051] The number of cells in the postbiotic sample calculated by the counting plate is: 1.86×10 11 Pieces / g.

[0052] 2.5 Determination of sodium content The sodium content was determined using inductively coupled plasma mass spectrometry (ICP-MS).

[0053] Weigh 1g of postbiotic sample into a tall beaker, add 150mL of deionized water and 10mL of nitric acid, heat on a hot plate at 180°C for 30min, cool and pour into a volumetric flask, dilute to 500mL with deionized water, mix and filter the sample, pour into a 50mL beaker. Take 2.5mL of sample solution and pour into a volumetric flask, dilute to 25mL with deionized water, dilute this solution 10 times in the same way, mix well and put on the machine. The sodium content in the low-sodium, salt-reduced and fresh-enhanced postbiotics was 5350mg / 100g.

[0054] Example 2 A low-sodium, salt-reducing, and freshness-enhancing postbiotic The preparation method is different from that of Example 1 in the following ways: In step (2), the third-grade seed liquid is inoculated at a rate of 5% and transferred to the fermentation medium and stirred for 8 minutes. The fermentation is carried out at 35°C until the pH of the fermentation liquid reaches 4.6. The fermentation is stopped and heat-inactivated at 115-120°C for 10 minutes.

[0055] When the solid content of the inactivated fermentation broth in step (3) reaches 65%, concentration is stopped.

[0056] The rest is consistent with the example, and the metabolites and bacterial counts in the postbiotics are detected.

[0057] The detection results of aroma active compounds are shown in Table 4. Compared with the results in Table 1, the concentrations of aroma active compounds are increased, but the sour taste and steamed and roasted taste are stronger.

[0058] Table 4 Detection results of aroma active compounds in low sodium, salt-reduced and fresh-enhanced postbiotics

[0059] The results of flavor amino acid determination are shown in Table 5. After low sodium and salt reduction and freshness enhancement, the content of flavor-related amino acids in the raw materials reached 2291.61 mg / L, the umami taste was more obvious, but the bitter flavor was also increased.

[0060] Table 5 Free amino acid content in low sodium, salt-reduced and fresh-enhanced postbiotics

[0061] The results of the determination of salty peptides are shown in Table 6, among which peptides with a molecular weight of <1000Da still account for the largest proportion, with a stronger flavor, but increasing product costs.

[0062] Table 6 Distribution percentage of polypeptides in low sodium, salt-reduced and fresh-enhanced postbiotics

[0063] The number of postbiotic bacteria in the low-sodium, salt-reducing and fresh-enhancing postbiotic sample was calculated using a counting plate: 2.32×10 11 / g; the measured sodium content in postbiotics is 5735mg / 100g.

[0064] Example 3 A low-sodium, salt-reducing, freshness-enhancing postbiotic The preparation method is different from that of Example 1 in the following ways: In step (2), the third-grade seed liquid is inoculated at a rate of 1% and transferred to the fermentation medium and stirred for 8 minutes. The fermentation is carried out at 39°C until the pH of the fermentation liquid reaches 4.7. The fermentation is stopped and heat-inactivated at 115-120°C for 10 minutes.

[0065] When the solid content of the inactivated fermentation broth in step (3) reaches 55%, concentration is stopped.

[0066] The rest is consistent with the example, and the metabolites and bacterial counts in the postbiotics are detected.

[0067] The results of the aroma active compound determination are shown in Table 7. The concentration of the aroma active compound is low and the overall flavor is not prominent.

[0068] Table 7 Detection results of aroma active compounds in low sodium, salt-reduced and fresh-enhanced postbiotics

[0069] The results of flavor amino acid determination are shown in Table 8. The content of flavor-related amino acids in low-sodium, salt-reduced and fresh-enhanced post-biotin reached 2104.68 mg / L, which is relatively low.

[0070] Table 8 Free amino acid content in low sodium, salt-reduced and fresh-enhanced postbiotics

[0071] The results of the determination of salty peptides are shown in Table 9. Peptides with a molecular weight of <1000 Da accounted for 66.33%, and the strong flavor was relatively light.

[0072] Table 9 Distribution percentage of polypeptides in low sodium, salt-reduced and fresh-enhanced postbiotics

[0073] The number of bacteria in the postbiotic sample was calculated by counting the plate: 1.32×10 11 / g; the sodium content in the postbiotics was measured to be 4898mg / 100g.

[0074] Example 4 Application of a low-sodium, salt-reducing and fresh-enhancing postbiotic in potato chip products 4.1 How to make potato chips (1) Select potatoes of uniform size and free of pests and diseases, wash and drain with clean water, remove the skin, cut the potatoes into 1-2 mm thick slices, and soak them in clean water to wash away the starch on the surface of the potato slices. After draining the water, put them in the oven and bake them in 4 groups. The oven setting parameters are 190℃, 45min.

[0075] (2) Preparation of postbiotic samples The postbiotic sample obtained in Example 1 was diluted with sterile maltodextrin in a certain proportion and then added. According to the requirements for bacterial count in standard T / CBFIA09001-2023 "Lactic Acid Postbiotics in Probiotic Products", the postbiotic was diluted to 3×10 10 Pieces / g added.

[0076] (3) Preparation of postbiotic potato chips When the potato chips are baked to 2 / 3 done (about 25 minutes), take out the potato chips and add sprinkles on the surface. No. 1# represents the full salt solution, with an addition amount of 5%; No. 2#, 3# and 4# represent the addition of 5% postbiotics, 5.5% postbiotics and 6.0% postbiotics respectively. Place in the oven and continue baking. After baking, take out and cool, and then test the relevant indicators.

[0077] 4.2 Determination of sodium content in potato chips Referring to the experimental steps in 2.5 of Example 1, the measurement results are shown in Table 10.

[0078] Table 10 Sodium content determination results of each group

[0079] Compared with the full salt solution, the sodium content was reduced by 28.8% when 5% of post-biotics were added.

[0080] 4.3 Sensory evaluation of potato chips The effect of adding postbiotic Pbio-TNa on the original potato chips after 30% salt reduction was evaluated from five aspects: crispness, state, color, smell, and taste, with a total score of 100. The evaluation panel consisted of 20 members working in food-related fields, with a male-female ratio of 1:1. The sensory evaluation standard used was based on QB / T 2686-2005, which was modified according to the characteristics of this product, as shown in Table 11 below.

[0081] Table 11 Sensory evaluation of postbiotic Pbio-TNa in potato chips

[0082] The evaluation results are as follows Fig. 9 As shown, the appearance of potato chips is similar to Fig.10 shown. Figure 9-10 It can be concluded that adding postbiotics to potato chips has basically no significant effect on the surface state, crispness, and color of the product compared to the full salt solution. Even if the sodium content is reduced, it still provides a better taste and enhances the freshness and flavor of the product.

[0083] 4.4 Electronic nose and electronic tongue testing of potato chips Electronic nose and electronic tongue tests were performed on the full salt group 1# and the postbiotic groups 2#, 3#, and 4#, respectively. The results of the electronic nose and electronic tongue are shown in Fig.11 The results of the electronic nose showed that the response values ​​of different probes were slightly different, indicating that the odor similarity between different amounts of postbiotics added in the salt reduction scheme was very high, indicating that the addition of different proportions of postbiotics in the salt reduction scheme had no significant effect on the change in the odor of potato chip products; the results of the electronic tongue showed that compared with the 1# full salt flavor, the saltiness of the potato chips with the addition of postbiotics 2#, 3# and 4# was reduced, but the umami taste was improved, indicating that the addition of different proportions of postbiotics can give the product better umami and flavor while reducing the sodium content.

[0084] 4.5 Determination of bacterial counts in potato chips Four groups of potato chips were tested for bacterial counts, and the test results are shown in Fig.12 The results showed that the number of bacteria could be effectively detected when postbiotics were used in potato chips, and the number of bacteria increased with the increase of the added amount.

[0085] The application of postbiotics in potato chips has no significant effect on their state, texture, crispness and flavor. It can give the product better umami and flavor while reducing the sodium content. Adding postbiotics to low-sodium, salt-reducing and fresh-enhancing products can remove chemical food additives, while cleaning the label, and give the product a healthier concept.

[0086] Obviously, the above embodiments are only detailed descriptions of the present invention, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. Changes or modifications made without departing from the spirit of the present invention all belong to the protection claimed in the present invention.

Claims

1. A low-sodium, salt-reducing and freshness-enhancing postbiotic, characterized in that: The postbiotics include Lactobacillus paracasei ( Lacticaseibacillus paracasei ) The inactivated bacteria of Probio-37 and the metabolites of Lactobacillus paracasei Probio-37.

2. The postbiotic according to claim 1, characterized in that The viable count of the inactivated bacteria of Lactobacillus paracasei Probio-37 is ≥ 1.86×10 11 CFU / g.

3. The postbiotic according to claim 1, characterized in that The metabolites of Lactobacillus paracasei Probio-37 include flavor active compounds, flavor peptides and flavor amino acids.

4. The postbiotic according to claim 3, characterized in that The total content of the flavor amino acids is ≥ 2220 mg / L, and the content of umami amino acids in the flavor amino acids is ≥ 1370 mg / L.

5. The postbiotic according to claim 3, characterized in that The flavor peptides include one or more of umami peptides, thick flavor peptides, salty peptides and umami amino acids.

6. The postbiotic according to claim 5, characterized in that The umami peptide includes one or more of Gln-Leu, Pro-Glu-Thr, Ala-Pro-Ala and His-Val.

7. The postbiotic according to claim 5, characterized in that The salty peptides include one or more of Asp-Asp, Glu-Asp, Asp-Asp-Asp, Ser-Pro-Glu and Phe-Ile.

8. The method for preparing the postbiotic according to any one of claims 1 to 7, characterized in that: The following steps are involved: (1) activating the strain and expanding the culture to obtain the seed solution of Lactobacillus paracasei Probio-37; (2) inoculating the seed solution in step (1) into a fermentation medium, fermenting and culturing until the pH reaches 4.5-4.7, and stopping the fermentation to obtain a fermentation liquid; (3) inactivating the fermentation broth in step (2); (4) The inactivated fermentation broth is decolorized, concentrated and spray-dried to obtain postbiotics.

9. The preparation method according to claim 8, characterized in that: The inoculation amount of the seed liquid in step (2) is 1%-5%, and the temperature of the fermentation culture is 35°C-39°C.

10. The preparation method according to claim 8, characterized in that: The components of the fermentation medium in step (2) include: 1% defatted soy flour, 8% defatted milk powder and water.

11. The preparation method according to claim 8, characterized in that: The inactivation method in step (3) is selected from any one of thermal inactivation, chemical inactivation and biological inactivation.

12. The preparation method according to claim 8, characterized in that: The concentration conditions in step (4) include: vacuum degree ≥ -0.07 MPa, temperature 65-75°C, and solid content of the inactivated fermentation broth reaching 55-65%.

13. Use of the postbiotic according to any one of claims 1 to 7 or the postbiotic prepared by the preparation method according to any one of claims 8 to 12 in preparing food.

14. The use according to claim 13, characterized in that: The food comprises one or more of convenience food, biscuits, potatoes, puffed food, sauces, roasted food, nut products and meat products.

15. A potato chip, characterized in that: The method comprises adding the postbiotics described in any one of claims 1 to 7 or the postbiotics prepared by the preparation method described in any one of claims 8 to 12, and baking according to conventional operations to prepare potato chips.

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