Mildew-proof fermentation composition and application thereof

Abstract

The invention discloses a mildew-proof fermentation composition and application thereof, and belongs to the technical field of food preservation. The mildew-proof fermentation composition comprises the following raw materials: 40-60% of natural acidic leavening; 15 to 25% of a spice extract; 20-35% of a polysaccharide coating agent; 5 to 10% of a nanometer titanium dioxide-tea polyphenol hybrid material; and 3 to 8% of an epsilon-polylysine-trehalose covalent complex. Wherein the nano titanium dioxide-tea polyphenol hybrid material enhances the antibacterial effect through photocatalysis, and the epsilon-polylysine-trehalose covalent compound can respond to the pH change of the environment to realize intelligent release. And the polysaccharide coating agent is subjected to cross-linking modification by adopting oxidized starch and chitosan, so that the film-forming property is remarkably improved. The composition is applied to the surface of the meat product in a soaking or spraying manner, and can effectively inhibit the growth of mould, prolong the shelf life of the product and maintain the fermentation flavor and sensory quality of the meat product. All the components of the preservative are food-grade raw materials, so that the preservative is safe and non-toxic, and is particularly suitable for the fresh-keeping requirements of high-quality meat products.

Description

Technical Field

[0001] This invention relates to the field of food preservation technology, specifically to an anti-mold fermentation composition and its application. Background Technology

[0002] Meat products are highly susceptible to contamination by mold and spoilage microorganisms during processing and storage. This not only leads to decreased product quality and shortened shelf life but may also produce toxic metabolites, endangering consumer health. Traditional preservation methods mainly rely on chemically synthesized preservatives such as nitrites and benzoic acid. While these are effective, long-term consumption may pose potential health risks. With increasing consumer concern about food safety, developing natural, efficient, and safe preservation technologies has become a current research hotspot.

[0003] Currently, using natural preservatives alone, such as organic acids, spice extracts, or polysaccharides, often suffers from limited effectiveness and short duration of action. For example, while acidic fermentation products can lower pH and inhibit some microorganisms, their inhibitory effect on mold is insufficient; spice extracts have broad-spectrum antibacterial properties, but they are volatile and have poor stability; polysaccharide coating agents can block oxygen and moisture, but lack active antibacterial function. How to construct a composite preservation system that combines antibacterial, film-forming, and fermentation functions through the synergistic effect of multiple components is a pressing technical challenge that needs to be addressed.

[0004] In recent years, nanotechnology and molecular modification have provided new insights into improving the performance of natural preservatives. Combining photocatalytic materials with plant polyphenols can enhance the killing effect on mold spores; while chemical modification of polysaccharide materials can significantly improve their film-forming properties and mechanical strength. However, existing technologies have not yet effectively integrated these innovative methods, particularly lacking a systematic solution in the field of meat product mold prevention and preservation. Therefore, developing a composite fermentation composition that integrates natural antibacterial properties, intelligent release, and functional film formation is of great significance. Summary of the Invention

[0005] The purpose of this invention is to provide an anti-mold fermentation composition and its application, which solves the problems of poor safety of existing anti-mold fermentation agents, single and short-lasting effects of natural preservatives, and lack of active antibacterial function.

[0006] The present invention achieves the above objectives through the following technical solutions:

[0007] A fermentation composition, characterized in that, by mass percentage, its raw materials comprise:

[0008] Natural acidic fermentation products: 40-60%;

[0009] Spices extract: 15-25%;

[0010] Polysaccharide film-forming agents: 20-35%;

[0011] Nano-titanium dioxide-tea polyphenol hybrid material: 5-10%;

[0012] ε-polylysine-trehalose covalent complex: 3-8%;

[0013] The preparation steps of the nano-titanium dioxide-tea polyphenol hybrid material include: mixing 20 mL of tetrabutyl titanate with 40 mL of anhydrous ethanol and stirring magnetically to obtain solution A; separately mixing 10 mL of deionized water, 30 mL of ethanol and 2 mL of glacial acetic acid to obtain solution B, adding it dropwise to solution A and stirring continuously until a translucent sol is formed; aging the sol in a water bath to obtain nano-TiO2 sol; dissolving tea polyphenols in 50 mL of pH 5.0 acetate buffer and activating it with 0.05 g of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide; slowly adding the activated tea polyphenol solution to the TiO2 sol, centrifuging the reaction solution, washing the precipitate obtained by centrifugation with ethanol three times; pre-freezing the purified precipitate at -80℃ and then freeze-drying it.

[0014] According to a preferred embodiment of the present invention, the tetrabutyl titanate was purchased from Shandong Jianbang New Material Co., Ltd.

[0015] According to a preferred embodiment of the present invention, the anhydrous ethanol was purchased from Shandong Juxing Chemical Co., Ltd.

[0016] According to a preferred embodiment of the present invention, the deionized water was purchased from Shanghai Binrun Environmental Protection Technology Co., Ltd.

[0017] According to a preferred embodiment of the present invention, the glacial acetic acid was purchased from Shandong Yukang Chemical Co., Ltd.

[0018] According to a preferred embodiment of the present invention, the tea polyphenols were purchased from Zhengzhou Longsheng Chemical Products Co., Ltd.

[0019] According to a preferred embodiment of the present invention, the acetate buffer solution is purchased from Shanghai Yuanye Biotechnology Co., Ltd., model R27590.

[0020] According to a preferred embodiment of the present invention, the 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide was purchased from [source missing].

[0021] In this invention, regarding the acid-base-antibacterial synergy, the microenvironment created by the acidic fermentation product promotes the maintenance of the non-dissociated state of spice phenols, enhancing their membrane permeability. Simultaneously, the low pH increases the positive charge density of ε-PL, strengthening its electrostatic interaction with the microbial membrane. Regarding the physical-chemical barrier synergy, nano-ZnO in the polysaccharide membrane forms a heterojunction with nano-titanium dioxide-tea polyphenol hybrid materials, generating localized photocatalytic sterilization at membrane damage sites. The confinement effect of the membrane structure prolongs the action time of reactive oxygen species. Regarding the temporal control synergy, the acidic fermentation product and spices provide immediate protection, the photocatalytic material achieves continuous action, and the intelligent response complex is activated when the pH rises in the later stages of spoilage, forming a complete time-sensitive protection chain.

[0022] According to a preferred embodiment of the present invention, the preparation steps of the nano-titanium dioxide-tea polyphenol hybrid material include: mixing 20 mL of tetrabutyl titanate with 40 mL of anhydrous ethanol, and magnetically stirring for 30 min at 25°C to obtain solution A; separately mixing 10 mL of deionized water, 30 mL of ethanol, and 2 mL of glacial acetic acid to obtain solution B, adding solution B dropwise to solution A at a dropping rate of 1 mL / min, and continuously stirring until a translucent sol is formed; aging the sol in a 40°C water bath for 24 h to obtain nano-TiO2 sol; dissolving 1 g of tea polyphenols in 50 mL of pH 5.0 acetic acid buffer, and adding 0.05 g of... 1-Ethyl-3-(3-dimethylaminopropyl)carbodiimide was activated at room temperature for 30 min. The activated tea polyphenol solution was slowly added to TiO2 sol at a volume ratio of 1:5, and the reaction was carried out at 60℃ for 6 h. The reaction solution was centrifuged at 12000 rpm for 15 min, and the precipitate was washed three times with ethanol. The purified precipitate was pre-frozen at -80℃ for 4 h, and then freeze-dried for 24 h to obtain porous nano-hybrid materials.

[0023] In this invention, the phenolic hydroxyl groups of tea polyphenols in the nano-titanium dioxide-tea polyphenol hybrid material react with the TiO2 surface Ti 4+ The formation of Ti-OC bonds introduces impurity energy levels into the band gap, expanding the photoresponse range. Tea polyphenols, acting as electron donors, match their HOMO energy levels with the TiO2 valence band, achieving efficient electron injection. Electrons in the electron-hole pairs generated by photoexcitation of TiO2 are captured by the catechol structure of tea polyphenols, forming semiquinone radical intermediates. Holes migrate to the particle surface to oxidize organic matter. This Z-shaped heterojunction structure significantly reduces the carrier recombination rate. Photogenerated holes directly oxidize the unsaturated fatty acids in the fungal cell membrane. Hydroxyl radicals attack the β-1,3-glucan chains in the cell wall, leading to structural disintegration. The galloyl group of tea polyphenols specifically binds to the thiol groups of fungal proteins, blocking enzyme activity.

[0024] According to a preferred embodiment of the present invention, the natural acidic ferment is selected from Lactobacillus plantarum fermentation broth or apple cider vinegar concentrate with a pH of 3.5-4.0.

[0025] According to a preferred embodiment of the present invention, the Lactobacillus plantarum fermentation broth was purchased from Guangzhou Huihe Biotechnology Co., Ltd.

[0026] According to a preferred embodiment of the present invention, the apple cider vinegar concentrate was purchased from Anhui Guoyi Pharmaceutical Co., Ltd.

[0027] In this invention, the natural acidic fermentation product, due to its low pH characteristics (pH 3.5-4.0), generates hydrogen ions through the dissociation of organic acids (lactic acid, acetic acid, etc.), lowering the environmental pH value. This disrupts the proton pump system of the microbial cell membrane, causing an imbalance in intracellular pH homeostasis and inhibiting the activity of key enzymes. Simultaneously, the non-dissociated organic acid molecules penetrate the cell membrane and dissociate intracellularly, releasing H+. + Increased acidification leads to the accumulation of anions, which compete with metabolic intermediates for binding sites, blocking the glycolysis pathway. Lactic acid can also specifically inhibit the mitochondrial electron transport chain in molds. The acidic environment also alters the fluidity of microbial cell membranes, affecting the function of membrane-bound proteins. Short-chain fatty acids (such as decanoic acid) in fermentation products act as quorum sensing inhibitors, interfering with the acyl homoserine lactone signaling system in molds, preventing the expression of virulence factors and biofilm formation. The acidic environment also promotes the growth of beneficial bacteria such as lactic acid bacteria, which inhibit mold reproduction by competing for nutrients and colonization sites and produce antimicrobial peptides such as bacteriocins to form a biological protective barrier.

[0028] According to a preferred embodiment of the present invention, the spice extract comprises thymol, capsaicin, and cinnamaldehyde.

[0029] According to a preferred embodiment of the present invention, the thymol was purchased from Jiangsu Xinsu New Materials Co., Ltd.

[0030] According to a preferred embodiment of the present invention, the capsaicin was purchased from Shaanxi Junhe Biotechnology Co., Ltd.

[0031] According to a preferred embodiment of the present invention, the cinnamaldehyde was purchased from Shaanxi Chenming Biotechnology Co., Ltd.

[0032] In this invention, the phenolic hydroxyl groups of thymol in the spice extract insert into the phospholipid bilayer of the microbial cell membrane, increasing membrane permeability and causing ion gradient collapse. Its hydrophobic benzene ring structure interferes with the hydrophobic core region of membrane proteins, inactivating proteins that maintain membrane integrity. The α,β-unsaturated aldehyde group of cinnamaldehyde undergoes a Michael addition reaction with aminophospholipids in the membrane lipids, altering the membrane phase transition temperature. Capsaicin penetrates the membrane structure through hydrophobic long-chain alkyl groups and binds to the hydrophobic pockets of intrinsic membrane proteins, inhibiting their activity. During the oxidation of these phenolic compounds to quinone intermediates by intracellular peroxidases in microbial cells, NADH is consumed, generating reactive oxygen species, while simultaneously chelating intracellular Fe. 2+Blocking the Fenton reaction leads to the accumulation of hydroxyl radicals, causing oxidative damage; cinnamaldehyde can covalently modify fungal histone deacetylases, affecting epigenetic regulation; thymol downregulates the expression of fungal ABC transporter genes, reducing the synthesis of resistance efflux pumps.

[0033] According to a preferred embodiment of the present invention, the preparation method of the polysaccharide coating agent includes: dispersing 10g of starch in 100mL of deionized water, adding 0.5mol / L NaIO4 solution, wherein the molar ratio of starch to NaIO4 is 1:0.8, stirring in the dark; adding 10mL of ethylene glycol to terminate the reaction, centrifuging, washing the precipitate three times with ethanol, and freeze-drying to obtain oxidized starch; dissolving 2g of chitosan in 100mL of 1% acetic acid solution, stirring until completely dissolved, adjusting the pH to 5.5 with 0.1M NaOH; adding 0.1g of genipin, reacting at 40℃; dispersing 5g of oxidized starch in 50mL of deionized water, adding the activated chitosan solution, reacting at 60℃ for 6h; adding 0.5g of NaBH4, reacting for 1h, and then dialyzing; adding 0.2% glycerol to the complex solution, concentrating under reduced pressure to a solid content of 10%; doping with 0.5% nano ZnO, and ultrasonically dispersing to obtain a multifunctional complex.

[0034] According to a preferred embodiment of the present invention, the preparation method of the polysaccharide coating agent includes: dispersing 10g of starch in 100mL of deionized water, adding 0.5mol / L NaIO4 solution, wherein the molar ratio of starch to NaIO4 is 1:0.8, stirring at 25°C in the dark for 24h to generate dialdehyde starch; adding 10mL of ethylene glycol to terminate the reaction, centrifuging at 5000rpm for 10min, washing the precipitate three times with ethanol, and freeze-drying to obtain oxidized starch; dissolving 2g of chitosan in 100mL of 1% acetic acid solution, stirring until completely dissolved, adjusting the pH to 5.5 with 0.1M NaOH; adding 0.1g of genipin, reacting at 40°C for 2h to form a partially cross-linked chitosan network; dispersing 5g of oxidized starch in 50mL of deionized water, adding the activated chitosan solution, reacting at 60°C for 6h at pH 5.0; adding 0.5g of... NaBH4 was reacted for 1 hour, and then dialyzed to remove small molecule impurities. 0.2% glycerol was added to the complex solution, and the solution was concentrated under reduced pressure at 50°C to a solid content of 10%. 0.5% nano ZnO was doped, and the solution was ultrasonically dispersed at 300W for 30 minutes to obtain a multifunctional complex.

[0035] According to a preferred embodiment of the present invention, the starch was purchased from Beijing Gusong Economic and Trade Co., Ltd.

[0036] According to a preferred embodiment of the present invention, the NaIO4 solution was purchased from Jinan Huifengda Chemical Co., Ltd.

[0037] According to a preferred embodiment of the present invention, the ethylene glycol was purchased from Jinan Huifengda Chemical Co., Ltd.

[0038] According to a preferred embodiment of the present invention, the chitosan was purchased from Zhengzhou Longsheng Chemical Products Co., Ltd.

[0039] According to a preferred embodiment of the present invention, the acetic acid solution was purchased from Beijing Haifuda Technology Co., Ltd.

[0040] According to a preferred embodiment of the present invention, the NaOH was purchased from Xi'an Xibao Chemical Additives Factory.

[0041] According to a preferred embodiment of the present invention, the NaBH4 was purchased from Wuhan Hezhong Biochemical Manufacturing Co., Ltd.

[0042] According to a preferred embodiment of the present invention, the glycerin was purchased from Zhongshan Hualong Glycerin Products Co., Ltd.

[0043] According to a preferred embodiment of the present invention, the nano-ZnO was purchased from Shandong Ruiqi Chemical Co., Ltd.

[0044] In this invention, the aldehyde groups of oxidized starch and the amino groups of chitosan in the polysaccharide coating agent form a covalent cross-linked network through a Schiff base reaction. Genipin is introduced as a cross-linking agent to enhance the three-dimensional stability of the isoprene skeleton. NaBH4 reduces C=N bonds to CN bonds to prevent acid hydrolysis. The carboxyl groups of oxidized starch and the amino groups of chitosan form a polyelectrolyte complex to generate a dense "ionic cross-linked" region that blocks oxygen permeation. Nano-ZnO doping forms a tortuous path to extend the diffusion distance of water molecules. Glyceryl plasticizer is inserted between polymer chains to increase the chain segment mobility and improve the elongation at break. The superhydrophilic surface of the composite film prevents the adhesion of proteins and microorganisms.

[0045] According to a preferred embodiment of the present invention, the preparation steps of the ε-polylysine-trehalose covalent complex include: dissolving 1g of ε-polylysine in 50mL of PBS buffer and stirring until completely transparent; dissolving 2g of trehalose in 20mL of deionized water; mixing the ε-polylysine solution and the trehalose solution at a mass ratio of 1:2 and adjusting the pH to 8.5; stirring, adding 10mL of ethanol to terminate the reaction, and cooling; placing the reaction solution into a dialysis bag and dialyzing it with deionized water at 4°C; pre-freezing the solution after dialysis and freeze-drying it to obtain a white porous solid.

[0046] According to a preferred embodiment of the present invention, ε-PL solution and trehalose solution are mixed at a mass ratio of 1:2, and the pH is adjusted to 8.5; the mixture is stirred at 55°C in the dark for 48 hours, and the reaction degree is measured every 12 hours; 10 mL of cold ethanol at 4°C is added to terminate the reaction, and the mixture is cooled in an ice bath; the reaction solution is placed in a dialysis bag and dialyzed with deionized water at 4°C for 48 hours, with the water changed every 8 hours to remove unreacted small molecules; the dialysis solution is pre-frozen at -80°C for 4 hours and freeze-dried for 24 hours to obtain a white porous solid.

[0047] According to a preferred embodiment of the present invention, the ε-polylysine was purchased from Shandong Pingju Biotechnology Co., Ltd.

[0048] According to a preferred embodiment of the present invention, the PBS buffer was purchased from Beijing Bio-Rad Laboratories Co., Ltd.

[0049] According to a preferred embodiment of the present invention, the trehalose was purchased from Shandong Yatu Biotechnology Co., Ltd.

[0050] In this invention, the ε-polylysine-trehalose covalent complex forms an N-substituted-1-amino-1-deoxyketose derivative through the Maillard reaction between the ε-amino group of ε-PL and the reducing end group of trehalose. Under acidic conditions, secondary amine matrix protonation enhances intramolecular hydrogen bonding, forming a compact spherical structure. At pH > 6.5, deprotonation leads to conformational relaxation, exposing degradation sites. Trehalose forms a glassy matrix that encapsulates ε-PL and creates water channels in a humid environment to control the release rate. The released ε-PL adsorbs onto the microbial cell membrane through electrostatic interactions and forms ion channels due to the negative surface charge. After the α-helical structure of ε-PL inserts into the membrane bilayer, its hydrophobic side interacts with lipids, while the hydrophilic side forms hydration channels, leading to intracellular K+. + It can cause ATP leakage and simultaneously bind to DNA to inhibit topoisomerase activity.

[0051] The present invention also provides an application of the fermentation composition in preventing mold.

[0052] The beneficial effects of this invention are as follows:

[0053] The fermentation composition provided by this invention exhibits excellent anti-mold and preservation effects. Through the synergistic effect of natural acidic fermentation products and spice extracts, it can effectively inhibit the growth and reproduction of various common molds without adversely affecting the original flavor of meat products. The active ingredients in the composition can form a long-lasting protective barrier on the surface of meat products, significantly extending the shelf life of the products.

[0054] The polysaccharide coating agent used in this composition undergoes special modification treatment, exhibiting excellent film-forming properties and mechanical strength, enabling it to form a uniform and dense protective layer on the surface of meat products. Combined with the photocatalytic activity of the nano-titanium dioxide-tea polyphenol hybrid material and the pH-responsive characteristics of the ε-polylysine-trehalose covalent complex, multiple inhibition and intelligent control of mold are achieved.

[0055] The fermentation composition of this invention not only has a significant anti-mold effect but also maintains the good sensory quality of meat products. All components are food-grade raw materials, safe and non-toxic, and easy to use. It can be used for both industrial production and home cooking, providing a reliable solution for the safe preservation of meat products. Practical application verification shows that meat products treated with this composition can remain mold-free for extended periods under normal storage conditions without affecting the normal fermentation process. Detailed Implementation

[0056] The following detailed embodiments are only used to further illustrate this application and should not be construed as limiting the scope of protection of this application. Those skilled in the art can make some non-essential improvements and adjustments to this application based on the above application content.

[0057] I. Implementation Examples

[0058] Example 1

[0059] Raw material ratio: 500g of natural acidic fermentation product (Lactobacillus plantarum fermentation broth, pH 3.8); 200g of spice extract (containing 15% thymol, 5% capsaicin, and 80% cinnamaldehyde); 300g of polysaccharide coating agent (oxidized starch-chitosan complex); 80g of nano-titanium dioxide-tea polyphenol hybrid material; and 50g of ε-polylysine-trehalose covalent complex.

[0060] Preparation steps: Preparation of nano-titanium dioxide-tea polyphenol hybrid material: Mix 20 mL of tetrabutyl titanate with 40 mL of anhydrous ethanol and stir magnetically at 25 °C for 30 min to obtain solution A; Mix 10 mL of deionized water, 30 mL of ethanol, and 2 mL of glacial acetic acid, and add to solution A dropwise at 1 mL / min, stirring continuously until a semi-transparent sol is obtained; Aged in a water bath at 40 °C for 24 h to obtain nano-TiO2 sol; Dissolve 1 g of tea polyphenol in 50 mL of pH 5.0 acetate buffer, and add 0.05 g of EDC to activate for 30 min; Mix the activated tea polyphenol solution and TiO2 sol at a volume ratio of 1:5, and react at 60 °C for 6 h; Centrifuge at 12000 rpm for 15 min, wash the precipitate three times with ethanol, pre-freeze at -80 °C for 4 h, and freeze-dry for 24 h to obtain porous hybrid material (80 g).

[0061] Preparation of polysaccharide coating agent: 10g starch was dispersed in 100mL deionized water, and 0.5mol / L NaIO4 solution was added (starch:NaIO4 = 1:0.8 molar ratio). The mixture was stirred at 25℃ in the dark for 24h. The reaction was terminated by adding 10mL ethylene glycol, centrifuged at 5000rpm for 10min, washed three times with ethanol, and freeze-dried to obtain oxidized starch. 2g chitosan was dissolved in 100mL 1% acetic acid solution, the pH was adjusted to 5.5, 0.1g genipin was added, and the mixture was reacted at 40℃ for 2h. 5g oxidized starch was dispersed in 50mL water, chitosan solution was added, and the mixture was reacted at pH 5.0 and 60℃ for 6h. 0.5g NaBH4 was added and the mixture was reacted for 1h. After dialyzing, 0.2% glycerol was added, and the mixture was concentrated under reduced pressure at 50℃ to a solid content of 10%. 0.5% nano ZnO (1.5g) was doped, and the mixture was sonicated at 300W for 30min to obtain a composite coating agent (300g).

[0062] Preparation of ε-polylysine-trehalose covalent complex: 1 g of ε-polylysine was dissolved in 50 mL of PBS buffer, and 2 g of trehalose was dissolved in 20 mL of water. The mixture was prepared at a mass ratio of 1:2 and the pH was adjusted to 8.5. The mixture was stirred at 55 °C in the dark for 48 h, and the reaction was monitored every 12 h. The reaction was terminated by adding 10 mL of cold ethanol, cooled in an ice bath, and dialyzed for 48 h (4 °C). The mixture was pre-frozen at -80 °C for 4 h and freeze-dried for 24 h to obtain a white solid (50 g).

[0063] Composition formulation: Mix 500g of Lactobacillus plantarum fermentation broth, 200g of spice extract, 300g of polysaccharide coating agent, 80g of nano-hybrid material, and 50g of ε-polylysine complex, and stir in a homogenizer (8000rpm) for 20min to obtain a homogenized fermentation composition (1130g).

[0064] Example 2

[0065] Raw material quality: 450g of natural acidic fermentation product (apple cider vinegar concentrate); 180g of spice extract; 350g of polysaccharide coating agent; 100g of nano-hybrid material; 60g of ε-polylysine complex.

[0066] Example 3

[0067] Raw material composition: 550g natural acidic fermentation product; 220g spice extract; 250g polysaccharide coating agent; 60g nano-hybrid material; 40g ε-polylysine complex. Preparation steps: The freeze-drying time of the nano-hybrid material was shortened to 12h.

[0068] Comparative Example 1

[0069] Raw material composition: 500g natural acidic fermented product; 200g spice extract; 300g polysaccharide coating agent; 50g ε-polylysine complex. Preparation steps: Directly mix and homogenize, without adding nano-TiO2-tea polyphenol material.

[0070] Comparative Example 2

[0071] Raw material quality: 500g natural acidic fermentation product; 50g sodium benzoate; 50g potassium sorbate; 300g polysaccharide coating agent; Preparation steps: replace bioactive ingredients with chemical preservatives.

[0072] Comparative Example 3

[0073] Raw material composition: 500g natural acidic fermentation product; 200g spice extract; 300g polysaccharide coating agent; 80g nano-hybrid material. Preparation steps: The preparation steps of the ε-polylysine-trehalose complex are omitted.

[0074] II. Performance Testing

[0075] 1. Anti-mildew performance test method

[0076] The fermentation compositions prepared in Examples 1-3 and Comparative Examples 1-3 were uniformly coated onto the surface of cooked meat sausages (coating amount 1 g / 100 cm²). 2 The mixture was placed in an incubator at 28±1℃ and 85% relative humidity, with untreated cooked meat sausages serving as a blank control. Mold growth was observed daily, and the time when visible mold spots appeared was recorded. The 7-day mold inhibition rate (%) was calculated as: (mold area in the control group - mold area in the treated group) / mold area in the control group × 100%. Simultaneously, the shelf life extension factor of the cooked meat sausages in each group was determined (calculated based on the time to obvious mold growth).

[0077] 2. Antibacterial spectrum test method

[0078] The inhibitory effect of the composition on common putrefactive bacteria was tested using the agar diffusion method. Suspensions of Aspergillus niger, Penicillium, Staphylococcus aureus, and Escherichia coli (10⁻⁶ g / L) were used. 6 The CFU / mL composition was evenly spread onto a PDA / NA plate. An Oxford cup containing 50 μL of the composition (100 mg / mL) was placed on the plate and incubated at 28°C (for molds) or 37°C (for bacteria) for 48 h. The diameter of the inhibition zone (mm) was then measured.

[0079] 3. Physicochemical stability testing methods

[0080] The composition was placed in a constant temperature and humidity chamber at 40℃ and 75% relative humidity for accelerated storage for 30 days. Samples were taken at 0, 15 and 30 days to determine: 1) pH value change (pH meter measurement); 2) retention rate of active ingredients (HPLC determination of tea polyphenols and ε-polylysine content); 3) viscosity change (rotational viscometer measurement at 25℃).

[0081] 4. Sensory evaluation methods

[0082] Ten trained evaluators conducted sensory evaluations (0-10 points) on the processed cooked meat sausages, including three indicators: appearance (degree of mold), odor (rancidity), and taste (preservative odor). The overall satisfaction rate (%) was calculated.

[0083] 5. Performance test results:

[0084] Table 1: Performance test results of each embodiment and comparative example

[0085]

[0086]

[0087] As shown in Table 1, the test results of this invention demonstrate that it has successfully solved several technical problems of existing anti-mold fermentation agents: In terms of safety, the sensory satisfaction of Examples 1-3 reached 88.7-92.5%, significantly better than Comparative Example 2 (72.4%) containing sodium benzoate, confirming that it avoids the safety risks of chemical preservatives; In terms of anti-mold effect, the 7-day mold inhibition rate of Example 1 (98.5%) was 16.4 percentage points higher than that of Comparative Example 1 (82.1%), and the shelf life was extended by 2.3 times, proving that the synergistic effect of nano-hybrid materials and bioactive components has broken through the limitation of the single effect of natural preservatives; The antibacterial spectrum test showed that the inhibition zone diameter of the Example group against the four test bacteria was >22.8 mm, especially the anti-mold effect was outstanding, indicating that it has a broad-spectrum active antibacterial function; In the stability test, the 30-day component retention rate of Example 1 was >94%, and the viscosity change rate was <5% (data not shown). Comparative Example 3 (lacking the ε-polylysine complex) showed a significant decrease in performance in all tests, further demonstrating that the present invention constructs a triple anti-corrosion system of "barrier protection - active sterilization - intelligent regulation" through multi-component molecular design, comprehensively solving the defects of the prior art.

[0088] The embodiments described above are merely examples of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention.

Claims

1. A fermentation composition, characterized in that, By weight percentage, its raw materials include: Natural acidic fermentation products: 40-60%; Spices extract: 15-25%; Polysaccharide film-forming agents: 20-35%; Nano-titanium dioxide-tea polyphenol hybrid material: 5-10%; ε-polylysine-trehalose covalent complex: 3-8%; The preparation steps of the nano-titanium dioxide-tea polyphenol hybrid material include: mixing 20 mL of tetrabutyl titanate with 40 mL of anhydrous ethanol and stirring magnetically to obtain solution A; separately mixing 10 mL of deionized water, 30 mL of ethanol and 2 mL of glacial acetic acid to obtain solution B, adding it dropwise to solution A and stirring continuously until a translucent sol is formed; aging the sol in a water bath to obtain nano-TiO2 sol; dissolving tea polyphenols in 50 mL of pH 5.0 acetate buffer and activating it with 0.05 g of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide; slowly adding the activated tea polyphenol solution to the TiO2 sol, centrifuging the reaction solution, washing the precipitate obtained by centrifugation with ethanol three times; pre-freezing the purified precipitate at -80℃ and then freeze-drying it.

2. The fermentation composition according to claim 1, characterized in that, The preparation steps of the nano-titanium dioxide-tea polyphenol hybrid material include: mixing 20 mL of tetrabutyl titanate with 40 mL of anhydrous ethanol and stirring magnetically for 30 min at 25 °C to obtain solution A; separately mixing 10 mL of deionized water, 30 mL of ethanol, and 2 mL of glacial acetic acid to obtain solution B; adding solution B dropwise to solution A at a dropping rate of 1 mL / min and stirring continuously until a translucent sol is formed; aging the sol in a 40 °C water bath for 24 h to obtain nano-TiO2 sol; dissolving 1 g of tea polyphenols in 50 mL of pH 5.0 acetic acid buffer and adding 0.05 g of... 1-Ethyl-3-(3-dimethylaminopropyl)carbodiimide was activated at room temperature for 30 min. The activated tea polyphenol solution was slowly added to TiO2 sol at a volume ratio of 1:5, and the reaction was carried out at 60℃ for 6 h. The reaction solution was centrifuged at 12000 rpm for 15 min, and the precipitate was washed three times with ethanol. The purified precipitate was pre-frozen at -80℃ for 4 h, and then freeze-dried for 24 h to obtain porous nano-hybrid materials.

3. The fermentation composition according to claim 1, characterized in that, The natural acidic fermentation product is selected from Lactobacillus plantarum fermentation broth or apple cider vinegar concentrate with a pH of 3.5-4.

0.

4. The fermentation composition according to claim 1, characterized in that, The spice extract contains thymol, capsaicin, and cinnamaldehyde.

5. The fermentation composition according to claim 1, characterized in that, The preparation method of the polysaccharide coating agent includes: dispersing 10g of starch in 100mL of deionized water, adding 0.5mol / L NaIO4 solution, wherein the molar ratio of starch to NaIO4 is 1:0.8, stirring in the dark; adding 10mL of ethylene glycol to terminate the reaction, centrifuging, washing the precipitate three times with ethanol, and freeze-drying to obtain oxidized starch; dissolving 2g of chitosan in 100mL of 1% acetic acid solution, stirring until completely dissolved, adjusting the pH to 5.5 with 0.1M NaOH; adding 0.1g of genipin, reacting at 40℃; dispersing 5g of oxidized starch in 50mL of deionized water, adding the activated chitosan solution, reacting at 60℃ for 6h; adding 0.5g of NaBH4, reacting for 1h, and then dialyzing; adding 0.2% glycerol to the complex solution, concentrating under reduced pressure to a solid content of 10%; doping with 0.5% nano ZnO, and ultrasonically dispersing to obtain a multifunctional complex.

6. The fermentation composition according to claim 5, characterized in that, The preparation method of the polysaccharide coating agent includes: dispersing 10g of starch in 100mL of deionized water, adding 0.5mol / L NaIO4 solution (the molar ratio of starch to NaIO4 is 1:0.8), stirring at 25℃ in the dark for 24h to generate dialdehyde starch; adding 10mL of ethylene glycol to terminate the reaction, centrifuging at 5000rpm for 10min, washing the precipitate three times with ethanol, and freeze-drying to obtain oxidized starch; dissolving 2g of chitosan in 100mL of 1% acetic acid solution, stirring until completely dissolved, adjusting the pH to 5.5 with 0.1M NaOH; adding 0.1g of genipin, reacting at 40℃ for 2h to form a partially cross-linked chitosan network; dispersing 5g of oxidized starch in 50mL of deionized water, adding the activated chitosan solution, reacting at 60℃ for 6h at pH 5.0; adding 0.5g of... NaBH4 was reacted for 1 hour, and then dialyzed to remove small molecule impurities. 0.2% glycerol was added to the complex solution, and the solution was concentrated under reduced pressure at 50°C to a solid content of 10%. 0.5% nano ZnO was doped, and the solution was ultrasonically dispersed at 300W for 30 minutes to obtain a multifunctional complex.

7. The fermentation composition according to claim 1, characterized in that, The preparation steps of the ε-polylysine-trehalose covalent complex include: dissolving 1g of ε-polylysine in 50mL of PBS buffer and stirring until completely transparent; dissolving 2g of trehalose in 20mL of deionized water; mixing the ε-polylysine solution and the trehalose solution at a mass ratio of 1:2 and adjusting the pH to 8.5; stirring, adding 10mL of ethanol to terminate the reaction, and cooling; placing the reaction solution into a dialysis bag and dialyzing it with deionized water at 4℃; pre-freezing the solution after dialysis and freeze-drying to obtain a white porous solid.

8. The fermentation composition according to claim 7, characterized in that, The ε-PL solution and trehalose solution were mixed at a mass ratio of 1:2, and the pH was adjusted to 8.

5. The mixture was stirred at 55°C in the dark for 48 hours, and the reaction degree was measured every 12 hours. The reaction was terminated by adding 10 mL of cold ethanol at 4°C and then cooled in an ice bath. The reaction solution was placed in a dialysis bag and dialyzed with deionized water at 4°C for 48 hours, with the water changed every 8 hours to remove unreacted small molecules. After dialysis, the solution was pre-frozen at -80°C for 4 hours and then freeze-dried for 24 hours to obtain a white porous solid.

9. The use of a fermentation composition according to any one of claims 1-8, characterized in that, The application of the fermentation composition in mold prevention.

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