Hydrogel water-absorbing and antibacterial liner loaded with metagen as well as preparation method and application of hydrogel water-absorbing and antibacterial liner

Abstract

The invention discloses a retrogen-loaded hydrogel water-absorbing antibacterial liner as well as a preparation method and application thereof, and the preparation method comprises the following steps: mixing a gelatin solution and a dialdehyde starch solution to obtain a Ge-Ds solution; the preparation method comprises the following steps: mixing a bacterial cellulose solution with a Ge-Ds solution to prepare a Ge-Ds-Bc solution; and mixing the Postbio YDFF-3 solution with the Ge-Ds-Bc solution, heating and stirring, cooling the mixture to room temperature, pouring into a culture dish, transferring to the temperature of-20 DEG C, preserving for 24 hours, and freeze-drying to obtain the hydrogel water-absorbing antibacterial liner loaded with the metabiotics. According to the invention, gelatin, dialdehyde starch and bacterial cellulose are used as matrix substances, and the postbiotic postbioYDFF-3 is added as an antibacterial substance to prepare the water-absorbing antibacterial liner for refrigeration and preservation of grass carp, the water-absorbing antibacterial liner is used for absorbing blood water or percolate of grass carp meat and reducing moisture required by microbial reproduction, and the antibacterial effect of the postbiotic postbioYDFF-3 is utilized to improve the refrigeration and preservation effects of grass carp. Therefore, growth of spoilage microorganisms in the grass carp meat is inhibited, and the refreshing time of the grass carp meat is prolonged.

Description

Technical Field

[0001] This invention belongs to the field of biomaterials technology, specifically relating to a hydrogel absorbent and antibacterial liner loaded with post-biotics, its preparation method, and its application. Background Technology

[0002] Liners are typically placed between the tray packaging and the seafood. When blood and other tissue fluids seep from the fresh seafood onto the surface, the liner absorbs them quickly, reducing the amount of exudate and the water needed for microbial growth and reproduction, thus inhibiting bacterial growth. Currently, disposable absorbent liner is mostly used to absorb excess blood and water to extend the shelf life of seafood. However, these liners are mainly made of plastics such as PE film, PET film, and non-woven fabric, which contain microplastics and plasticizers that may contaminate food through direct contact with the seafood. Furthermore, these liners are disposable products with poor biodegradability, which is detrimental to green development. Therefore, there is an urgent need to develop environmentally friendly liner. Gelatin (Ge)-dialdehyde starch (Ds)-bacterial cellulose (Bc) liner is made from safe materials and will not contaminate seafood or reduce its quality. Moreover, compared with traditional disposable liner, this hydrogel liner has a simpler manufacturing process and a shorter biodegradability period, making it an excellent alternative to traditional disposable liner.

[0003] If absorbent liner only absorbs exudate but cannot inhibit the growth and reproduction of spoilage microorganisms in aquatic products, its preservation performance is very limited. Due to its loose, porous structure and high specific surface area, antibacterial substances can be introduced into the liner through spraying or mixing, creating novel preservation liner with both absorption and antibacterial properties. This effectively solves the problem of exudate from fresh aquatic products while inhibiting the growth of spoilage microorganisms, thus improving the preservation quality of aquatic products. Biological preservatives are non-toxic, harmless, and biodegradable, and are widely used in the preservation of fresh foods such as aquatic products. However, some biological preservatives, such as plant essential oils, while possessing good antibacterial and antioxidant properties, are limited in their application in liner applications due to difficulties in extraction, low product yield, and high cost.

[0004] PostbioYDFF-3 is a product obtained by inactivating bacterial fermentation broth. It possesses good antibacterial properties and is simple and inexpensive to prepare. However, there are currently no reports on directly adding postbioYDFF-3 to gelatin (Ge)-dialdehyde starch (Ds)-bacterial cellulose (Bc) liners to form liners with high water absorption and antibacterial properties. Summary of the Invention

[0005] The purpose of this section is to outline some aspects of the embodiments of the present invention and to briefly describe some preferred embodiments.

[0006] In view of the problems existing in the above and / or prior art, the present invention is proposed.

[0007] Therefore, the purpose of this invention is to overcome the shortcomings of the prior art and provide a method for preparing a hydrogel absorbent and antibacterial liner loaded with biogener.

[0008] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a method for preparing a hydrogel absorbent and antibacterial liner loaded with post-biotic, comprising, Gelatin solution and dialdehyde starch solution are mixed to obtain Ge-Ds solution; A Ge-Ds-Bc solution was prepared by mixing a bacterial cellulose solution with a Ge-Ds solution. Postbio YDFF-3 solution was mixed with Ge-Ds-Bc solution, heated and stirred, and then cooled to room temperature. The mixture was poured into a petri dish, stored at -20°C for 24 hours, and then freeze-dried to obtain a hydrogel absorbent and antibacterial liner loaded with bio-based prebiotics.

[0009] In a preferred embodiment of the preparation method described in this invention, the concentration of the gelatin solution is 7 wt%.

[0010] In a preferred embodiment of the preparation method described in this invention, the concentration of the dialdehyde starch is 6 wt%.

[0011] In a preferred embodiment of the preparation method described in this invention, the concentration of the bacterial cellulose solution is 2 wt%.

[0012] In a preferred embodiment of the preparation method described in this invention, the volume ratio of the gelatin solution, dialdehyde starch solution, and bacterial cellulose solution is 3:1:0.5.

[0013] In a preferred embodiment of the preparation method described in this invention, the volume ratio of the Postbio YDFF-3 solution to the Ge-Ds-Bc solution is 1:1.

[0014] In a preferred embodiment of the preparation method described in this invention, the concentration of the Postbio YDFF-3 solution is 7 wt%.

[0015] Another objective of this invention is to overcome the shortcomings of the prior art and provide a hydrogel absorbent and antibacterial liner loaded with post-biotics.

[0016] Another objective of this invention is to overcome the shortcomings of the prior art and provide an application of a hydrogel absorbent and antibacterial liner in the preservation of aquatic products.

[0017] Beneficial effects of this invention: (1) This invention utilizes the Schiff base reaction to prepare a Ge-Ds-Bc hydrogel pad with good adsorption capacity. The adsorption rate reaches 660.4% within 60 minutes, and its gel strength is strong, at 1.75 g / cm. The antibacterial ability of the pad is improved by adding the postbiotic PostbioYDFF-3. At the same time, the addition of the postbiotic PostbioYDFF-3 can increase the preservation period of grass carp by 48 hours, thereby improving the preservation ability of the pad. Postbiotics are non-living microbial components or mixtures thereof that are beneficial to the health of the host. These components include bacterial cell components (such as peptidoglycan, teichoic acid, lipopolysaccharide, etc. on the cell wall) and metabolites (such as short-chain fatty acids, vitamins, enzymes, extracellular polysaccharides, etc.). Postbiotics have advantages such as safety and non-toxicity and convenient preparation, making them an excellent choice when adding bactericides to the pad. The absorbent pad prepared by the Schiff base reaction between Ge and Ds has the characteristics of fine pores, which provides good conditions for the loading of postbiotics and the absorption of water, and has advantages such as safety, environmental protection, and good flexibility.

[0018] (2) In this invention, 7wt% Postbio YDFF-3 solution is added mainly for the purpose of bactericide. It not only has an excellent inhibitory effect on the relevant putrefactive bacteria, but also affects the microstructure of Ge-Ds-Bc liner. The pore and network structure of the liner are optimized and the water absorption capacity is enhanced, which is 51% higher than that without the addition of Postbio YDFF-3.

[0019] (3) Ge-Ds-Bc-P liners have advantages such as easy operation, safety and reliability, and environmental friendliness, and are an effective way to improve the preservation effect of aquatic products. Attached Figure Description

[0020] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Wherein: Figure 1 The figures show the gel strength of Ge-Ds with different matrix ratios and the gel strength of Ge-Ds-Bc with different matrix ratios in the embodiments of the present invention. In the figure, A is the gel strength of Ge-Ds with different matrix ratios (p<0.05) and B is the gel strength of Ge-Ds-Bc with different matrix ratios (p<0.05).

[0021] Figure 2The images shown are Fourier transform infrared (FTIR) and X-ray diffraction (XRD) spectra of the products obtained in the embodiments of the present invention. In this embodiment, A is the Fourier transform infrared spectrum of Ge-Ds-Bc pads with different contents of Postbio YDFF-3, and B is the X-ray diffraction spectrum of Ge-Ds-Bc pads with different contents of Postbio YDFF-3.

[0022] Figure 3 The images shown are scanning electron microscope (SEM) images of Ge-Ds-Bc pads with different amounts of Postbio YDFF-3 added in the embodiments of the present invention. A to E represent the amounts of Postbio YDFF-3 added, which are 0%, 3%, 5%, 7%, and 10%, respectively.

[0023] Figure 4 The graphs show the adsorption capacity, antibacterial activity, and pH changes of grass carp meat placed on Ge-Ds-Bc pads with different amounts of Postbio YDFF-3 in this embodiment of the invention. In this graph, A shows the adsorption capacity (p<0.05) of Ge-Ds-Bc pads with different amounts of Postbio YDFF-3, B shows the antibacterial activity (p<0.05) of Ge-Ds-Bc pads with different amounts of Postbio YDFF-3, and C shows the pH changes (p<0.05) of grass carp meat placed on Ge-Ds-Bc pads with different amounts of Postbio YDFF-3.

[0024] Figure 5 These are graphs showing the changes in total bacterial count (TVC) and color of grass carp meat placed on Ge-Ds-Bc liners with different amounts of Postbio YDFF-3 in embodiments of the present invention. Graph A shows the change in total bacterial count (TVC) (p<0.05) of grass carp meat placed on Ge-Ds-Bc liners with different amounts of Postbio YDFF-3, and graph B shows the change in color of grass carp meat placed on Ge-Ds-Bc liners with different amounts of Postbio YDFF-3.

[0025] Figure 6The figures show the changes in thiobarbituric acid active substances (TBARS) and volatile basic nitrogen (TVB-N) in grass carp meat placed on Ge-Ds-Bc liners with different amounts of Postbio YDFF-3 in embodiments of the present invention. Figure A shows the changes in thiobarbituric acid active substances (TBARS) in grass carp meat placed on Ge-Ds-Bc liners with different amounts of Postbio YDFF-3 (p<0.05), and Figure B shows the changes in volatile basic nitrogen (TVB-N) in grass carp meat placed on Ge-Ds-Bc liners with different amounts of Postbio YDFF-3 (p<0.05). Detailed Implementation

[0026] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the examples in the specification.

[0027] The characteristic analysis method of Ge-Ds-Bc-P gasket in this embodiment of the invention: (1) Determination of gel strength The prepared liner was fixed on a TMS-pilot texture analyzer, and the gel strength of the liner was measured using a P / 32R probe. Throughout the process, the descent speed of the stable probe was 1 mm / s, the strain was 50%, and the triggering force was 49 N. The units were g / cm.

[0028] (2) Determination of Fourier Transform Infrared Spectroscopy (FTIR) The Fourier transform infrared spectra of the hydrogel were determined using a Thermo Avatar 370 spectrometer and KBr technique, with a wavelength range of 4000 cm⁻¹. -1 Up to 500 cm -1 The resolution is 4 cm. -1 .

[0029] (3) X-ray diffraction (XRD) measurement XRD patterns were observed using a Philips X'pert-MPD diffractometer at 40 kV and 40 mA under Cu Kα radiation (λ = 0.154 nm), with an angle range of 5°–80°. The interplanar spacing was calculated using Bragg's law: 2d sinθ = nλ, where d is the interplanar spacing (α), θ is the diffraction angle (°), λ is the wavelength (nm), and n is the reflection order.

[0030] (4) Measurement by scanning electron microscopy (SEM) The pad was broken into fragments under liquid nitrogen conditions and then sputtered with gold. The cross-sectional microstructure of the absorber pad was observed using a scanning electron microscope S-4800 with an accelerating voltage of 5 kV and a magnification of 400x.

[0031] (5) Determination of the adsorption capacity of Ge-Ds-Bc-P pad At room temperature, 1 g of Ge-Ds-Bc-P pads were directly immersed in 30 mL of physiological saline. The weight of the precipitate during the adsorption process was monitored using an analytical balance at 5, 10, 20, 30, 40, 50, and 60 min. The adsorption rate of the Ge-Ds-Bc-P pads was calculated using the following formula: (M: initial weight; M0: weight after adsorption) Test results of the application of Ge-Ds-Bc-P gasket in this embodiment of the invention: (1) Antibacterial activity test of Ge-Ds-Bc-P liner The effect of the liner on the coating plate method was evaluated. P. putida NBRC 14164 and A. johnsonii ANC 3681 Its antibacterial activity; Both bacterial strains were initially activated in NB nutrient broth at 30°C for 12 hours; After three passages, the cells were centrifuged at 10,000g for 10 min.

[0032] The precipitate was resuspended in 0.9% sterile saline (SPSS, pH 7.4) to a final concentration of 10. 7 CFU / mL; Cut the Postbio YDFF-3 liner containing 3%, 5%, 7%, and 10% postbiotics into uniform cubes (1×1×1cm). 3 The samples were added to two different bacterial suspensions and cultured at 30°C for 12 hours. The samples were then serially diluted with physiological saline at a ratio of 1:9 to obtain bacterial suspensions of different concentrations. The diluted samples were cultured on agar plates (100 µL). The bacterial survival rate was determined based on the ratio of the number of colonies in the post-biological group to the number of colonies in the control group.

[0033] (2) pH value determination During storage at 4°C, 3g of fish fillets were taken out daily, chopped, homogenized with 30mL of distilled water, and then measured with a pH meter.

[0034] (3) Determination of total bacterial count (TVC) Aseptically pack 3g of chopped fish fillets into a 30×25cm container. 2 The sterile homogenizing bag contains fish meat in a 1:9 ratio (m / v). The sample was homogenized with sterile physiological saline for 10 min; after homogenization, the sample was continuously diluted 10 times. The diluted sample solution (100 μL) was inoculated onto agar plates, which were then incubated at 37°C for 24 h to determine the total colony count. TVC is expressed as logarithmic colony-forming units per milliliter (log). 10 CFU / mL (4) Determination of thiobarbituric acid active substances (TBARS) The chopped fish fillet sample was homogenized with a 10% trichloroacetic acid (TCA) solution at a ratio of 4:1 (m / v); the mixture was filtered to obtain a clear solution. Transfer the filtrate to a test tube with a screw cap, which has been pre-filled with an equal volume of 0.02 M TBARS solution; heat the test tube in boiling water for 20 min. After cooling, the absorbance of the reaction mixture at a wavelength of 532 nm was measured using a UV-1000 spectrophotometer, with a reagent blank as a reference. The absorbance readings were compared with the standard curve to determine the TBARS value, which is expressed as mgMDA eq / kg.

[0035] (5) Determination of volatile basic nitrogen (TVB-N) The chopped fish fillet sample was homogenized in pre-cooled sterile water for 3 min; after centrifugation at 4 ℃ and 4000 g for 15 min, a certain amount of magnesium oxide (MgO) was added to the supernatant, and the mixture was then poured into a digestion tube; the TVB-N value was determined using a fully automated Kjeltec 9 nitrogen analyzer, and the TVB-N value was expressed as mg / 100g.

[0036] In this embodiment of the invention, the postbiotic YDFF-3 was purchased from Qingdao Yuanda Biotechnology Co., Ltd., and is a commercially available product. The gelatin was purchased from Shanghai Maclean Biochemical Technology Co., Ltd., and is a commercially available product. Dialdehyde starch was purchased from Shanghai Beyotime Biotechnology Co., Ltd., and is a commercially available product. Bacterial cellulose was purchased from Shanghai Maclean Biotechnology Co., Ltd., and is a commercially available product.

[0037] Example 1 Ge-Ds liner preparation: Solutions with a final concentration of 7% Ge (gelatin, m / v) and 6% Ds (dialdehyde starch, m / v) were mixed uniformly at volume ratios of 1:1, 2:1, 3:1 and 4:1 (v / v), respectively. The mixed solution was heated at 90℃ for 30 min to crosslink, the pH was adjusted to 7.5, and then heated for another 30 min to obtain a gel solution; After defoaming under vacuum, the solution (30g) was poured into a petri dish (90mm in diameter), cooled to room temperature, and then placed at -20℃ for 24 h.

[0038] The gel strength of the Ge-Ds liner is as follows: Figure 1 As shown in Figure A, with the increase of Ge content, the gel strength of Ge-Ds pads showed a trend of first increasing and then decreasing; the gel strength of absorbent pads with added Ds was higher than that of the control group without added Ds; when Ge:Ds was 3:1, the gel strength of Ge-Ds-Bc pads reached the maximum value of 1.74 g / cm (p<0.05), which was the best. There was no significant difference in gel strength between Ge:Ds of 1:1, 2:1 and 4:1 and without added Ds (p>0.05).

[0039] Example 2 Preparation of Ge-Ds-Bc liner: Add 2g of Bc to 100ml of water (25℃) and stir to prepare a 2% Bc solution. The prepared 2% Bc mixed solution (bacterial cellulose, solution B) was added to the solution (solution A) with the optimal Ge-Ds matrix ratio (Ge:Ds is 3:1, refer to Example 1); Solution A and solution B were uniformly mixed at volume ratios of 1:0.1, 1:0.2, 1:0.3, 1:0.4 and 1:0.5 (v / v), respectively. The mixed solution was heated at 90℃ for 30 min to crosslink, the pH was adjusted to 7.5, and then heated for another 30 min to obtain a gel solution; After defoaming under vacuum, the solution (30g) was poured into a petri dish (90mm in diameter), cooled to room temperature, and then placed at -20℃ for 24 h.

[0040] like Figure 1 As shown in B, the gel strength gradually increases within a certain limit as the amount of Bc added increases; When the Ge:Ds:Bc ratio is 3:1:0.5, the gel strength of the liner reaches its maximum value of 1.75 g / cm (p<0.05), which is similar to the gel strength when Ge:Ds is 3:1, indicating that this matrix ratio is optimal. Ge:Ds:Bc ratios of 3:1:0.3, 3:1:0.4, and 3:1:0.6 exhibit good gel strength, while Ge:Ds:Bc ratios of 3:1:0.1 and 3:1:0.2 show the worst gel strength.

[0041] Example 3 Preparation of a gelatin (Ge)-dialdehyde starch (Ds)-bacterial cellulose (Bc)-postbiotic PostbioYDFF-3 liner: (1) Preparation of Ge-Ds-Bc-P gasket 3%, 5%, 7% and 10% of Postbio YDFF-3 (labeled as P) were added to the solution with the optimal Ge-Ds-Bc matrix ratio (solution C, refer to Example 2). Solutions C and P were mixed uniformly at a volume ratio of 1:1 (v / v); After heating and stirring for 20 min, the mixture was cooled to room temperature, poured into a 90 mm petri dish, and stored at -20 °C for 24 h. The sample was then placed in a Christ freeze dryer at -51 °C for 36 h for subsequent experimental measurements and analysis.

[0042] (2) Preparation of Postbio YDFF-3 and grass carp meat samples Postbio YDFF-3 was dissolved in sterile water and centrifuged for 15 min (4000 g, 4 °C) using a Sigma 4 K15 centrifuge to remove insoluble impurities. The solution was then diluted with sterile water to prepare solutions with concentrations of 30 mg / mL (3%), 50 mg / mL (5%), 70 mg / mL (7%), and 100 mg / mL (10%).

[0043] Fresh grass carp, weighing approximately 2.3 ± 0.2 kg, were purchased from a local seafood supermarket. After removing the head, scales, and entrails, the fish were rinsed thoroughly, covered with crushed ice, and transported to the laboratory within 25 minutes. The dorsal muscle was manually cut into similar cubes, measuring (4 × 3 × 0.5 cm). 3 ), for use in subsequent experiments.

[0044] Fish fillets were randomly divided into two groups: one group was placed on a mat containing Postbio YDFF-3 (referred to as the postbiotic group), and the other group was placed on a mat without Postbio YDFF-3 (referred to as the control group). Both groups of samples were placed in sterile bags and stored at 4°C for subsequent analysis.

[0045] (3) Ge-Ds-Bc-P gasket analysis Fourier transform infrared (FTIR) analysis of Ge-Ds-Bc-P pads: Fourier transform infrared spectroscopy mainly determines the structure, chemical bonds, and vibrational states of atoms in a sample by measuring the absorption of infrared light, thereby enabling the analysis and identification of the sample.

[0046] like Figure 2 As shown in Figure A, the epigenetic group and the control group exhibit similar peak shapes. In the Ge-Ds-Bc substrate, the peak near 1660 cm⁻¹ corresponds to the characteristic peak of the C=N double bond; this indicates that at 1660 cm⁻¹... -1 At the site, Ge and Ds underwent a Schiff base reaction in the Ge3:Ds1:Bc0.5 system, forming an imine bond (C=N). The postgeneric Postbio YDFF-3 exhibits unique stretching vibration characteristics between the C=O and C=N double bonds. Furthermore, with the addition of Postbio YDFF-3, the imine bond shows a trend of initial strengthening followed by weakening, and the C=C and C=O bonds show a similar trend.

[0047] The shapes of C=N, C=C and C=O bonds at the Ge3:Ds1:Bc0.5:P (7%) concentration were more pronounced compared to those at other Postbio YDFF-3 concentrations (p<0.05). The liner prepared in the ratio of Ge3:Ds1:Bc0.5 was used at 3360 cm. -1 The characteristic peak is observed at this point, corresponding to the stretching vibration of the OH bond. The postgenetic group also shows the stretching vibration of the OH bond at the same wavenumber.

[0048] As the concentration of Postbio YDFF-3 increases, the changes in OH bonds exhibit a peak shape; the OH bond peak shape of Ge3:Ds1:Bc0.5:P (7%) is similar to that of Ge3:Ds1:Bc0.5. However, Ge3:Ds1:Bc0.5:P (10%) almost completely loses its OH bonds. This may be because the acidic substances in Postbio YDFF-3 break the imine bonds and soften Bc, thereby weakening the water absorption capacity of the liner. This demonstrates that the addition of less than 7% Postbio YDFF-3 may not affect the stability of the Ge-Ds-Bc liner.

[0049] X-ray diffraction (XRD) analysis of Ge-Ds-Bc-P pads: XRD reflects the crystal structure of a material, and the XRD pattern of the pad is as follows: Figure 2As shown in Figure B, with the increase of PostbioYDFF-3 concentration, the peak shape of the XRD pattern first increases and then decreases, with the peak value (2θ) ranging from 10° to 22.5°. The diffraction peaks of the Ge-Ds-Bc-P adsorbent pad are generally not high, with a peak observed near 2θ = 14.7°, which is related to the crystal structure of Bc. The characteristic peaks of Bc between 2θ = 13.4° and 18.1° are clearly visible. The peak value at 14.7° in the postbiotic group increases from 3% to 7%, which may be due to the large number of hydrogen bonds generated after the crosslinking of gelatin and diformaldehyde starch. The postbiotic group shows a broad peak and two sharp peaks at 22.5°, 31.4°, and 46.2°, respectively. At the peak value of 46.2°, the postbiotic group shows a trend of first increasing and then decreasing, which may be due to the enhanced hydrogen bonding between various functional groups. This proves that the postbiotic PostbioYDFF-3 has been crosslinked into the hydrogel matrix. The decrease in XRD value in the 10% postbiotic group may be due to the weakening of hydrogen bonds caused by excessive addition of PostbioYDFF-3. Therefore, among all experimental groups, the cross-linking effect of gelatin, dialdehyde starch, and bacterial cellulose was relatively the best in the 7% PostbioYDFF-3 addition group.

[0050] Example 4 Based on the Ge-Ds-Bc-P pad prepared in Example 3, the Ge-Ds-Bc-P pad was analyzed by scanning electron microscopy (SEM).

[0051] like Figure 3 As shown, it can be clearly observed that the Ge3:Ds1:Bc0.5 liner exhibits a sheet-like thin-walled structure with a small number of continuous pore networks. Figure 3 A); the liner containing 3% Postbio YDFF-3 exhibited brittleness, with increased pore size and thickened pore walls, resulting in a poor microstructure. Figure 3 (B) This phenomenon may be due to the fragility of the cross-linked network structure caused by cell membrane proteins in the postbiotic PostbioYDFF-3. It is possible that a large number of cell membrane proteins cause network fragility through adhesion and binding in Bc, and the fragility of Bc, in turn, leads to increased pore size and thickened walls in the network structure.

[0052] like Figure 3As shown in C and D, the decrease in brittleness is accompanied by a gradual reduction and homogenization of the pore size within the cross-linked network. This may be due to the increased concentration of the postbiotic YDFF-3, which in turn leads to an increased concentration of organic acids. These organic acids may cause cell membrane proteins to separate from Bc and may oxidize some of the Bc, leading to a Schiff base reaction with Ge, thereby restoring the liner's toughness and network structure. When the concentration of the postbiotic YDFF-3 is 7%, the pore and network structure are optimized, and the liner's water absorption capacity may be enhanced, resulting in a relatively optimal microstructure. However, when the concentration of the postbiotic YDFF-3 reaches 10%, the cross-linked network structure deteriorates, cracks appear, leading to increased pore size, reduced pore number, and the worst microstructure. This may be caused by excessive organic acids. In environments with high acid concentrations, the Schiff base reaction is more likely to occur hydrolyze, and organic acids can also soften Bc.

[0053] This suggests that the concentration of organic acid may exceed the tolerance limit of the schaff base reaction (10% of the postbiotic YDFF-3), and further softening of Bc would weaken its water absorption capacity. This further explains the weakening of the Ge3:Ds1:Bc0.5:P (10%) OH bond in the Fourier transform infrared spectrum (e.g., Figure 2 (As shown in Figure A). This also explains the decrease in peak intensity at 46.2° for the 10% postgenetic group in the XRD spectrum (Figure 2B).

[0054] Example 5 Based on the Ge-Ds-Bc-P pad prepared in Example 3, the adsorption capacity of the Ge-Ds-Bc-P pad was analyzed: The water absorption capacity was further verified by Fourier transform infrared spectroscopy, X-ray diffraction, and scanning electron microscopy.

[0055] As shown in Figure 4A, the water absorption capacity of both the postbiotic group and the control group showed a gradual increasing trend. The 7% postbiotic group exhibited the best water absorption capacity (p<0.05), reaching an adsorption rate of 660.4% at 60 minutes, while the control group's adsorption rate at the same time was only 609.4%. Furthermore, the 10% postbiotic group showed a significant decrease in water absorption capacity, with an adsorption rate of only 318.5% at the same time, exhibiting the worst adsorption capacity. These results are consistent with the peak intensity changes of the -OH bond in the Fourier transform infrared spectrum. The excellent water absorption of the pad is attributed to the chemical reaction between Ge and Ds, which forms a dense network structure. The addition of Bc promotes the binding of hydroxyl groups with more water molecules. Moreover, when the concentration of the postbiotic Postbio YDFF-3 increased to 10%, the water absorption capacity decreased. This may be due to the interaction between the organic acid and Schiff base in the postbiotic Postbio YDFF-3, which weakens the interfacial bonds and increases the difficulty of water molecule binding.

[0056] Analysis of the antibacterial activity of Ge-Ds-Bc-P liner: Measuring the antibacterial activity of absorbent pads can directly assess the strength of their antibacterial ability. like Figure 4 As shown in Figure B, the results indicated that the four different concentrations of the liner exhibited good antibacterial activity against *P. putida* NBRC 14164 and *A. johnsonii* ANC 3681. With increasing concentration, the survival rate of both strains decreased, indicating that the postbiotic Postbio YDFF-3 provides resistance to both bacteria. The survival rate of *P. putida* NBRC 14164 was lower than that of *A. johnsonii* ANC 3681.

[0057] When the concentration of postbiotic YDFF-3 reached 7%, the survival rates of *P. putida* NBRC 14164 and *A. johnsonii* ANC 3681 were only 13.4% and 14.1%, respectively, representing a decrease of 65.6% and 65.9% compared to the control group. When the concentration of postbiotic YDFF-3 reached 10%, the survival rates of *P. putida* NBRC 14164 and *A. johnsonii* ANC 3681 reached 12.6% and 13%, respectively, showing no significant difference compared to the 7% postbiotic YDFF-3 treatment (p>0.05).

[0058] Therefore, it is speculated that the presence of postbiotics may disrupt bacterial cell membranes by absorbing water and releasing the postbiotic Postbio YDFF-3, thereby inactivating bacteria. The optimal amount of Postbio YDFF-3 added may be between 5% and 10%.

[0059] pH analysis of Ge-Ds-Bc-P liner: The initial pH value of fresh grass carp meat is between 6.2 and 6.3 (e.g., Figure 4 (As shown in C). The pH values ​​of both the postbiotic group and the control group showed a gradual upward trend. The pH decrease on day 2 was likely due to the production of lactic acid and phosphate from a series of anaerobic glycolysis and ATP degradation processes. A significant difference was observed between the postbiotic group and the control group after day 2 (p<0.05). The pH value of the control group reached 7.6, while the pH value of the postbiotic group decreased by 10.5% to 14.5% by day 5. The pH value with the addition of 7% Postbio YDFF-3 postbiotic liner was only 6.5. The later increase in pH value was likely due to volatile alkalis produced by protein decomposition. The results indicate that the postbiotic liner effectively inhibits the production of amine compounds by microorganisms.

[0060] Example 6 Based on the Ge-Ds-Bc-P gasket prepared in Example 3: (1) Analysis of total bacterial count on Ge-Ds-Bc-P liner: The initial TVC of fresh grass carp meat is typically 2-3 logs. 10 CFU / mL, the maximum acceptable threshold for fish is 6log 10 CFU / mL.

[0061] like Figure 5 As shown in Figure A, the TVC of the control group and the post-genetic group showed a gradual upward trend, with the TVC of all samples around 2.16 log [data missing]. 10 CFU / mL to 2.2 log 10 The levels were between CFU / mL. The control group exceeded the upper limit, reaching 6.4 log on day 5. 10 The levels of CFU / mL were all below the upper limit in the post-natal group, with the highest value on that day being only 5.88 log [value missing]. 10 The concentration of CFU / mL indicates that the added Postbio YDFF-3 liner has a good antibacterial effect.

[0062] On day 5, the color of the post-natal group was more vibrant than that of the control group. Figure 5 B). Furthermore, the TVC in the 7% post-biotic group was lower than in other concentration groups, reaching only 5.55 log on day 5. 10 The optimal concentration of CFU / mL showed the best antibacterial effect. The antibacterial effects of the 5% and 10% postbiotic groups were slightly lower than those of the 7% postbiotic group, but the antibacterial effect was good. The antibacterial effect of the 3% postbiotic group was poor, but it was still significantly different from the control group (p<0.05).

[0063] (2) Analysis of Ge-Ds-Bc-P liner thiobarbituric acid active substances (TBARS): like Figure 6 As shown in Figure A, the initial value of fresh grass carp fillets was approximately 0.166 mg MDA eq / kg. Both the control and postbiotic groups showed an increasing trend, with significant differences between the two groups (p<0.05). This indicates that adding the postbiotic Postbio YDFF-3 to the liner effectively reduces MDA formation. The control group reached 1.15 mg MDA eq / kg on day 5, while the postbiotic group showed a decrease of 31.3%-36.5% compared to the control group, reaching 0.73-0.79 mg MDA eq / kg. It is speculated that the lower TBARS value in the postbiotic group may be due to the barrier effect of Postbio YDFF-3 penetrating into the fillets, thereby further reducing the grass carp fillets' exposure to oxygen.

[0064] (3) Analysis of volatile basic nitrogen (TVB-N) in Ge-Ds-Bc-P liner: like Figure 6 As shown in Figure B, the initial TVB-N content in fresh grass carp was approximately 5.77 mg / 100g. However, the TVB-N value in the control group reached 12.6 mg / 100g on day 5, close to the upper limit (13 mg / 100g), while the TVB-N value in the postbiotic group decreased by 26.6% to 9.25 mg / 100g. The lower TVB-N content in the postbiotic group may be due to the postbiotic PostbioYDFF-3 inhibiting the utilization and breakdown of proteins by enzymes and microorganisms; the addition of the postbiotic PostbioYDFF-3 liner can effectively reduce protein breakdown.

[0065] The liner previously produced using the Schiff base reaction between gelatin and dialdehyde starch had limited pH stability, meaning it couldn't maintain sufficient water retention in highly acidic or alkaline environments. Adding bacterial cellulose to this system, without affecting the liner's gel strength, increased the liner's applicability in highly acidic or alkaline environments. The addition of 7wt% Postbio YDFF-3 solution, primarily for bactericidal purposes, not only effectively inhibited related spoilage bacteria but also influenced the microstructure of the Ge-Ds-Bc liner, optimizing its pore and network structure and enhancing its water absorption capacity by 51% compared to without Postbio YDFF-3. Simultaneously, the addition of Postbio YDFF-3 enhanced the liner's antioxidant properties, resulting in a 48-hour increase in the shelf life of grass carp placed on the liner. The growth rates of TBARS and volatile basic nitrogen decreased significantly, indicating that the Ge-Ds-Bc-P liner can effectively inhibit the oxidative decomposition of proteins and fats. In addition, it was found that the fish meat placed on the Ge-Ds-Bc-P liner containing 7wt% Postbio YDFF-3 had a more vibrant color, which enhanced the sensory characteristics of the fish meat.

[0066] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the present invention.

Claims

1. A method for preparing a hydrogel absorbent and antibacterial liner loaded with post-biotics, characterized in that: include, Gelatin solution and dialdehyde starch solution are mixed to obtain Ge-Ds solution; A Ge-Ds-Bc solution was prepared by mixing a bacterial cellulose solution with a Ge-Ds solution. The Postbio YDFF-3 solution was mixed with the Ge-Ds-Bc solution, heated and stirred, and then cooled to room temperature. The mixture was poured into a petri dish, stored at -20°C for 24 hours, and then freeze-dried to obtain a hydrogel absorbent and antibacterial pad loaded with the Postbio YDFF-3.

2. The preparation method according to claim 1, characterized in that: The concentration of the gelatin solution is 7 wt%.

3. The preparation method according to claim 1 or 2, characterized in that: The concentration of the dialdehyde starch is 6 wt%.

4. The preparation method according to claim 3, characterized in that: The concentration of the bacterial cellulose solution is 2 wt%.

5. The preparation method according to claim 4, characterized in that: The volume ratio of the gelatin solution, dialdehyde starch solution, and bacterial cellulose solution is 3:1:0.

5.

6. The preparation method according to claim 1 or 5, characterized in that: The volume ratio of the Postbio YDFF-3 solution to the Ge-Ds-Bc solution is 1:

1.

7. The preparation method according to claim 6, characterized in that: The concentration of the Postbio YDFF-3 solution was 7 wt%.

8. The hydrogel absorbent and antibacterial liner loaded with post-biotics prepared by any of the preparation methods described in claims 1 to 7.

9. The application of the hydrogel absorbent and antibacterial liner according to claim 8 in the preservation of aquatic products.

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