Preparation method of polyphenol-polysaccharide synergistically-improved thermally-stable fish gelatin gel and 3D printing application of polyphenol-polysaccharide synergistically-improved thermally-stable fish gelatin gel

Abstract

The invention discloses a preparation method of polyphenol-polysaccharide synergistically-improved thermally-stable fish gelatin gel and 3D printing application of the polyphenol-polysaccharide synergistically-improved thermally-stable fish gelatin gel. According to the method, tannic acid and sodium carboxymethyl cellulose are introduced into a fish gelatin system and are fully stirred and mixed, and tannic acid as a cross-linking agent interacts with sodium carboxymethyl cellulose and fish gelatin to construct a more compact three-dimensional gel network, so that the preparation of the polyphenol and polysaccharide synergistically enhanced fish gelatin-based gel is realized. The gel shows excellent printing adaptability and structural stability in 3D printing application, geometric shapes can be accurately formed, the gel has wide application prospects in the fields of personalized food design, biological material manufacturing and the like, and a new technical path is provided for high-value development of fish gelatin.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of food gel materials and food 3D printing technology, and particularly relates to a preparation method of a polyphenol-polysaccharide synergistically improved heat-stable fish gelatin gel and 3D printing application thereof. BACKGROUND

[0002] Fish gelatin is a desirable substitute for mammalian gelatin. However, fish gelatin has obvious functional defects in practical application, mainly manifested in insufficient mechanical properties and poor thermal stability, and the melting temperature is significantly low, which leads to the phenomenon of softening or melting of the material at room temperature. The above performance short board seriously restricts the promotion of fish gelatin in high value-added fields, especially in application scenarios with high requirements for thermal stability, such as edible packaging, heat-sensitive food systems and 3D printed food.

[0003] In order to improve the performance of fish gelatin, the existing technology has tried to modify it by physical methods (such as ultrasonic, irradiation), chemical methods (such as phosphorylation, glycosylation) or biological methods (such as enzyme treatment). However, these methods still have limitations in improving the thermal stability of fish gelatin, especially in improving the melting temperature, which makes it difficult to effectively apply in scenarios requiring higher temperature stability. SUMMARY

[0004] In view of the above problems of the prior art, the present application proposes to introduce tannic acid and sodium carboxymethyl cellulose into the fish gelatin system, aiming to construct a polyphenol-polysaccharide synergistic three-dimensional network structure with thermal reversibility. This structure can not only improve the melting temperature and mechanical properties of fish gelatin, but also maintain good thermal reversible gel behavior, thereby enhancing its structure retention ability during printing forming and expanding its practical range in food and biomaterials.

[0005] The technical scheme is as follows: The first object of the present application is to provide a method for improving the thermal stability of fish gelatin gel by polyphenol-polysaccharide synergy, comprising the following steps: (1) mixing fish gelatin, sodium carboxymethyl cellulose, tannic acid and water, stirring and mixing uniformly to obtain a mixed system; (2) placing the obtained mixed system in a low temperature environment to form a stable three-dimensional gel network.

[0006] In an embodiment of the present application, the concentration of tannic acid in the mixed system is 0.02 wt%-0.06 wt%. Further preferably, it is 0.04 wt%-0.06 wt%.

[0007] In an embodiment of the present application, the concentration of sodium carboxymethyl cellulose in the mixed system is 0.45 wt%-0.55 wt%. Specifically, 0.5 wt% can be selected.

[0008] In one embodiment of the present application, the concentration of fish gelatin in the mixed system is 14 wt% ~ 16 wt%. Specifically, 15 wt% can be selected.

[0009] In one embodiment of the present application, step (1) specifically comprises: First, fish gelatin solution and sodium carboxymethyl cellulose solution are prepared; then deionized water, tannic acid and sodium carboxymethyl cellulose solution are mixed; finally, fish gelatin solution is added, and the solution is mixed uniformly by rapid stirring, to obtain the mixed system.

[0010] In one embodiment of the present application, the preparation process of the fish gelatin solution is as follows: fish gelatin solid is added to deionized water, and the water bath temperature is 45 ~ 55 ℃; the water bath time is 1 ~ 2 h.

[0011] In one embodiment of the present application, the preparation process of the sodium carboxymethyl cellulose solution is as follows: sodium carboxymethyl cellulose solid is added to deionized water, and the water bath temperature is 45 ~ 55 ℃; the water bath time is 20 ~ 40 min.

[0012] In one embodiment of the present application, the stirring conditions in step (1) are as follows: stirring is carried out at a speed of 300 ~ 500 rpm for 8 ~ 12 min at 45 ~ 55 ℃, until the system is completely uniform.

[0013] In one embodiment of the present application, in step (2), the mixed system is placed in an environment of 3 ~ 5 ℃, and is left to stand for 10 ~ 14 h, until the gel network is completely solidified.

[0014] In one embodiment of the method for constructing a fish gelatin-based gel three-dimensional network structure of the present application, the method is to introduce tannic acid and sodium carboxymethyl cellulose for synergistic crosslinking in the gel preparation process, wherein the tannic acid forms multiple hydrogen bonds and hydrophobic interactions with fish gelatin and sodium carboxymethyl cellulose through its polyphenol structure, to construct a long-range flexible crosslinking network; the sodium carboxymethyl cellulose assists in forming a uniform and dense multidimensional gel structure by providing hydrogen bond binding sites and steric hindrance effects.

[0015] The present application provides a heat-stable fish gelatin gel prepared based on the above method.

[0016] The present application also provides the application of the above heat-stable fish gelatin gel in 3D printing.

[0017] In an embodiment of the present application, the 3D printed model layer thickness is set to 0.5-1.5 mm, the printing filling density is set to 75%-85%, the printing environment temperature is 18-22 DEG C, the printing nozzle diameter is 1.1-1.3 mm, the material extrusion rate is 14-16 mm / s, and the nozzle moving rate is 19-21 mm / s.

[0018] The present application is based on the 3D printed product obtained by the above application method.

[0019] Beneficial effects (1) The present application successfully constructs a uniform and dense three-dimensional gel network with smaller micropore size through the synergistic effect of tannic acid and sodium carboxymethyl cellulose by using the polyphenol-polysaccharide synergistic modification technology. This structure brings breakthrough performance improvement to fish gelatin: the melting temperature is increased by 23.07%, the melting rate is delayed by 106.7%, the tensile strength is increased by 37.45%, and the elongation at break is greatly increased by 633.08%. The optimization of these key indicators significantly broadens the application range of fish gelatin in high-end food manufacturing and biomaterials.

[0020] (2) The present application successfully develops a polyphenol-polysaccharide synergistic modified heat-stable fish gelatin suitable for normal temperature 3D printing, which fundamentally overcomes the technical difficulty of fish gelatin melting and flowing at room temperature. The material shows excellent forming precision and structural stability in printing, with precise extrusion lines and no spillover, significantly reducing the dependence on high-energy consumption temperature control equipment, and providing an efficient and flexible solution for personalized food manufacturing. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 The visual pictures of the fish gelatin gels obtained in Example 1 and Comparative Examples 1-6.

[0022] Figure 2 The melting temperature diagram of the fish gelatin gels obtained in Example 1 and Comparative Examples 1-5.

[0023] Figure 3 The melting state diagram of the fish gelatin gels obtained in Example 1 and Comparative Examples 1-5 under the same environment.

[0024] Figure 4 The tensile strength result comparison diagram of the fish gelatin gels obtained in Example 1 and Comparative Examples 1-5.

[0025] Figure 5 The elongation at break result comparison diagram of the fish gelatin gels obtained in Example 1 and Comparative Examples 1-5. Figure 6 The intermolecular force diagram of the fish gelatin gels obtained in Example 1 and Comparative Examples 1-5.

[0026] Figure 7 Microstructure images of fish gelatin gels obtained for Example 1 and Comparative Examples 1-5.

[0027] Figure 8 Thixotropic property images of fish gelatin gels obtained for Example 1 and Comparative Examples 1-5.

[0028] Figure 9 Printing effect images of fish gelatin gels obtained for Example 1 and Comparative Examples 1-5.

[0029] Figure 10 Visual images of products obtained for Comparative Example 8. DETAILED DESCRIPTION

[0030] The preferred embodiments of the present application are described below, and it should be understood that the embodiments are for better explaining the present application, and are not used to limit the present application.

[0031] Test methods 1. Melting temperature test: A mixed rheometer was used to determine the gel melting temperature and gelation temperature of fish gelatin. A steel flat plate clamp with a diameter of 40 mm was used for analysis, and the sample was placed in the center of the platform. When the clamp was lowered to 1050 μm, the excess sample at the edge was absorbed, and the clamp was lowered to 1000 μm to start the test. A temperature scanning mode was selected to determine the linear viscoelastic region (LVR). When the temperature reached the set value, the sample was set to stabilize for 180 s before starting the test. The temperature scanning rate was 1 ℃ / min. When the storage modulus and the loss modulus intersected, i.e., the tan δ value was 1, the gel melting temperature and the gelation temperature were obtained. The initial temperature was 4 ℃, and the final temperature was 45 ℃ when the gel melting temperature was determined.

[0032] 2. Texture property test: A texture analyzer was used to determine the texture properties of fish gelatin treated in different ways. The sample was placed on the detection table, and the tensile strength and elongation at break were tested in the tensile mode. The texture analyzer probe was ATG, and the sample was cut into a rectangular shape with an effective size of 40 nm × 15 nm at 25 ℃. The initial separation distance of the upper grip and the head speed were set to 40 nm and 10 nm / min, respectively. TS (MPa) and EAB (%) were calculated using equations (1) and (2), respectively.

[0033] (1) (2) where F is the maximum force (N), A is the cross-sectional area of the sample (m 2 ), ΔL is the increase in length at break (nm), and L is the initial length of the sample (nm).

[0034] 3. Gel melting state diagram in the same environment: Inject fish gelatin solution into 10 mL sample bottle to 5 mL, stand at 4 ℃ to make it fully gel. Then, invert the sample bottle and place it in a 35 ℃ oven, record the time required for gel melting.

[0035] 4. A standard curve is made using bovine serum albumin as a standard. Prepare extract solutions A, B, C, and D according to the following method. Extract solution A: 0.05 mol / L NaCl. Extract solution B: 0.6 mol / L NaCl solution. Extract solution C: 1.5 mol / L urea and 0.6 mol / L NaCl solution. Extract solution D: 8 mol / L urea and 0.6 mol / L NaCl solution. Mix fish gelatin gel sample (1 g) with A-D extract solutions, and use a high-speed homogenizer at a speed of 8000 rpm / min for 1 min. After centrifugation at 10000 x g for 15 min, collect the supernatant. Take 0.1 mL of A-D extract solution in a test tube, then add 0.5 mL of Folin phenol solution A, mix well by vortex oscillation, stand at room temperature for 10 min, then add 0.05 mL of Folin phenol solution B, mix well by vortex oscillation again, and develop color for 30 min in a C water bath. Equilibrate the sample to room temperature, measure the absorbance value at 500 nm, and record it as SA, SB, SC, and SD. Calculate the ionic bond by SB-SA, the hydrogen bond by SC-SB, and the hydrophobic force by SD-SC.

[0036] 5. Microstructure test: Use a low-temperature scanning electron microscope to observe the microstructure of fish-derived gelatin gel. Cut the sample into about 1 mm x 1 mm x 0.5 mm strips in a low-temperature environment, then immediately insert it into the sample disc. After rapid cooling and fixation in a low-temperature transfer system with liquid nitrogen, the sample is sent into the vacuum chamber through a connecting rod, the sample surface is cut flat, and the sample is cut to form a cross-section. Finally, sublimate at -80 ℃ for 20 min, perform gold spraying, and observe the microstructure of the fish gelatin sample under a scanning electron microscope at 20000 x magnification.

[0037] 6. Thixotropic property test: Determine the thixotropy of fish gelatin gel samples in the shear scanning mode of a mixing rheometer, evaluate the thixotropic behavior, and observe the thixotropic loop. Use a steel flat plate clamp with a diameter of 40 mm, analyze it at 25 ℃, place the sample in the center of the platform, and when the clamp is lowered to 1050 μm, scrape off the excess sample at the edges. Then lower the clamp to 1000 μm to start testing. Set two programs, Program One: shear rate from 0.1 s -1 to 100 s -1 , collect data points; Program Two: shear rate from 100 s -1 to 0.1 s​-1 collecting data points.

[0038] Example 1 A preparation method of a polyphenol-polysaccharide synergistically improved heat-stable fish gelatin gel and its 3D printing application, characterized in that it comprises the following steps: (1) Solution preparation treatment: Take fish gelatin solid and add deionized water to a water bath pot for stirring until completely melted, with a water bath temperature of 50°C; the water bath time is 1.5 h, and a 30 wt% (300 mg / ml) fish gelatin solution is prepared. Take carboxymethyl cellulose sodium solid (viscosity: 600-1000 mpa.s) and add deionized water to a water bath pot for stirring until completely melted, with a water bath temperature of 50°C; the water bath time is 30 min, and a 5 wt% (50 mg / ml) carboxymethyl cellulose sodium solution is prepared.

[0039] (2) Mixing treatment: Mix a certain amount of deionized water, tannic acid, and carboxymethyl cellulose sodium solution, and finally add a certain volume of fish gelatin solution. After mixing, quickly stir to make the solution uniform, and obtain a mixed system; the final concentration of tannic acid in the mixed system is 0.06 wt%, the concentration of carboxymethyl cellulose sodium is 0.5 wt%, and the concentration of fish gelatin is 15 wt%.

[0040] (3) Standing treatment: Place the mixed system at 4°C for 12 h to obtain an improved heat-stable fish gelatin gel.

[0041] Comparative Example 1 Adjust the final concentration of tannic acid in Example 1 step (2) to 0, and the final concentration of carboxymethyl cellulose sodium to 0, and keep the others consistent with Example 1 to obtain a fish gelatin gel.

[0042] Comparative Example 2 Adjust the final concentration of tannic acid in Example 1 step (2) to 0.02%, and the final concentration of carboxymethyl cellulose sodium to 0, and keep the others consistent with Example 1 to obtain a fish gelatin gel.

[0043] Comparative Example 3 Adjust the final concentration of tannic acid in Example 1 step (2) to 0, and keep the others consistent with Example 1 to obtain a fish gelatin gel.

[0044] Comparative Example 4 Adjust the final concentration of tannic acid in Example 1 step (2) to 0.02%, and keep the others consistent with Example 1 to obtain a fish gelatin gel.

[0045] Comparative Example 5 Adjusting the final concentration of tannic acid in step (2) of Example 1 to 0.04%, and keeping the rest the same as Example 1, a fish gelatin gel was obtained.

[0046] Comparative Example 6 Adjusting the final concentration of tannic acid in step (2) of Example 1 to 0.08%, and keeping the rest the same as Example 1, a fish gelatin gel was obtained.

[0047] The prepared polyphenol-polysaccharide synergistically improved heat-stable fish gelatin gel was tested, and the test results were as follows: Figure 1 The visualized diagram of the polyphenol-polysaccharide synergistically improved heat-stable fish gelatin gel of Comparative Examples 1-6 and Example 1. From Figure 1 It can be seen that by comparing the appearance of gels with different amounts of tannic acid, the state is significantly affected by the concentration of tannic acid. At a lower concentration (≤0.06%), the system presents a uniform clear transparent gel; with further increase of the concentration of tannic acid, due to excessive crosslinking, protein aggregation is precipitated, and the gel system changes from a uniform state to produce white insoluble substances.

[0048] Figure 2 The melting temperature diagram of the polyphenol-polysaccharide synergistically improved heat-stable fish gelatin gel of Comparative Examples 1-5 and Example 1. From Figure 2 It can be seen that, Figure 2 The melting temperature diagram of the polyphenol-polysaccharide synergistically improved heat-stable fish gelatin gel of Comparative Examples 1-5 and Example 1. The specific results are shown in Table 1.

[0049] Table 1 Melting temperature results of fish gelatin gels obtained by different methods

[0050] From Figure 2 and Table 1, it can be seen that with the increase of the concentration of tannic acid added, the melting temperature of the fish gelatin-based gel is significantly improved. A higher concentration of polyphenol crosslinking agent can crosslink with fish gelatin through its quinone compound, forming a co-gel phase with more dense intermolecular connections and more reasonable structure, thereby giving the gel higher thermal stability and thermal hysteresis.

[0051] Figure 3 The gel melting state diagram of the polyphenol-polysaccharide synergistically improved heat-stable fish gelatin gel of Comparative Examples 1-5 and Example 1 under the same environment. From Figure 3It can be seen that the gels of Comparative Example 1 (unmodified) and Comparative Example 3 (CMC added only) completely melted within 15 minutes; while the composite system with tannic acid (TA) introduced showed a significant melting delay effect. With the increase of TA addition, the complete melting time of Comparative Example 4, Comparative Example 5 and Example 1 increased to 19, 24 and 31 minutes respectively, which were 26.7%, 60% and 106.7% longer than the control group. This phenomenon is attributed to the fact that TA constructs a denser three-dimensional network by enhancing hydrophobic interactions and hydrogen bond crosslinking, thereby significantly increasing the energy barrier required to destroy the gel structure and effectively delaying the melting process.

[0052] Figure 4 The tensile strength diagrams are for the polyphenol-polysaccharide synergistic improvement of heat-stable fish gelatin gels in Comparative Examples 1-5 and Example 1. Figure 5 The graph shows the elongation at break of the polyphenol-polysaccharide synergistic enhanced fish gelatin-based gels of Comparative Examples 1-5 and Example 1. Specific results are shown in Table 2.

[0053] Table 2 Melting temperature results of fish gelatin gels obtained by different methods

[0054] from Figures 4-5 As shown in Table 2, with the increase of tannic acid concentration, the tensile strength of the fish gelatin-based gel first increases and then decreases, while the elongation at break gradually increases. This indicates that tannic acid, sodium carboxymethyl cellulose, and fish gelatin molecules interact to form a denser, more stable, and flexible three-dimensional network structure. Specifically, tannic acid molecules act as cross-linking bridges, constructing a long-range flexible cross-linking system between protein and polysaccharide molecular chains through multiple hydrogen bonds, enhancing molecular chain compatibility, and ultimately synergistically improving the overall mechanical properties of the fish gelatin-based gel.

[0055] Figure 6 This is a diagram showing the intermolecular interactions between polyphenols and polysaccharides in comparative examples 1-5 and example 1, which synergistically improve the heat-stable fish gelatin gel. From... Figure 6 As can be seen, ionic bonds contribute relatively little in all systems. Hydrophobic interactions and hydrogen bonds are the main driving forces for gel network formation. In the fish gelatin-based gel system, hydrophobic interactions continuously increase with the addition of tannic acid, reaching a peak at a tannic acid addition of 0.06%. Sodium carboxymethyl cellulose assists network formation by providing hydrogen bonding sites and steric hindrance. The synergistic effect of tannic acid and sodium carboxymethyl cellulose ultimately manifests as a significant enhancement of hydrophobic interactions, with tannic acid-induced hydrophobic binding being dominant. The enhanced hydrophobic interactions promote the formation of a more uniform and stable gel network.

[0056] Figure 7Figure 1 shows the microstructure of the fish gelatin gel modified by polyphenol- polysaccharide synergistically in Comparative Examples 1-5 and Example 1. From Figure 1, it can be seen that the introduction of tannic acid significantly changes the gel network morphology. With the increase of tannic acid addition amount, the gel network pore size is significantly reduced, and the structure tends to be densified. The synergistic effect of tannic acid and sodium carboxymethyl cellulose promotes the formation of a dense and uniform three-dimensional network structure of fish gelatin-based gel network. Tannic acid molecules act as additional crosslinking points, enhancing the interaction between molecular chains and promoting molecular chain entanglement, which is the main reason for the reduction of pore size. Figure 7 Figure 2 shows the thixotropic properties of the fish gelatin gel modified by polyphenol- polysaccharide synergistically in Comparative Examples 1-5 and Example 1. From Figure 2, it can be seen that with the increase of tannic acid addition amount, the angle between the uplink and downlink scanning curves gradually decreases, and at higher concentrations, a rheological hysteresis loop is formed, and the area of the rheological hysteresis loop significantly increases, indicating that the thixotropy of the gel is enhanced. This corresponds to the structure recovery speed after gel deposition, and the strength is established faster, thereby improving its printing adaptability (such as better shape retention).

[0057] Figure 8 Figure 3 shows the 3D printing of the fish gelatin gel modified by polyphenol- polysaccharide synergistically in Comparative Examples 1-5 and Example 1. From Figure 3, it can be seen that the texture of the samples without tannic acid and with low concentration of tannic acid is rough, and the boundary is blurred. With the increase of tannic acid addition amount, the size resolution and surface texture quality gradually improve. The increase of tannic acid addition amount helps the gel forming, and the smoothness of the material extruded wire increases, which makes the precision of 3D printing continuously rise, and the surface of the product gradually becomes smooth. Figure 8

[0058] Figure 9 Figure 3 shows the 3D printing of the fish gelatin gel modified by polyphenol- polysaccharide synergistically in Comparative Examples 1-5 and Example 1. From Figure 3, it can be seen that the texture of the samples without tannic acid and with low concentration of tannic acid is rough, and the boundary is blurred. With the increase of tannic acid addition amount, the size resolution and surface texture quality gradually improve. The increase of tannic acid addition amount helps the gel forming, and the smoothness of the material extruded wire increases, which makes the precision of 3D printing continuously rise, and the surface of the product gradually becomes smooth. Figure 9 Effect of different polysaccharide selection in Comparative Example 7

[0059] In Comparative Example 7, the sodium carboxymethyl cellulose in Example 1 was replaced with an equal amount of other polysaccharide compounds in step (2), and the other conditions were the same as in Example 1, to obtain fish gelatin gels. The fish gelatin gels obtained were tested, and the results are shown in Table 3.

[0060] Table 3

[0061]

[0062] ​​As shown in Table 3, the melting temperature, tensile strength and elongation at break of fish gelatin gels added with chitosan or carrageenan are lower than those of the system added with sodium carboxymethyl cellulose. This is mainly due to the unique structural advantages of sodium carboxymethyl cellulose. Its anionic properties help to maintain the compatibility and uniformity of the system, and the rich hydroxyl and carboxyl groups in the molecular chain can synergistically build a strong hydrogen bond crosslinking network with tannic acid, thereby significantly improving the thermal stability and mechanical properties of the gel. In contrast, chitosan is prone to charge aggregation in the system, resulting in poor structural uniformity; while the gel formation of carrageenan depends on specific ions such as potassium and calcium, and lacks the corresponding ionic environment in the system of the present application, so it cannot achieve the same enhancement effect as sodium carboxymethyl cellulose.

[0063] Comparative Example 8 Control of polysaccharide-polyphenol synergistic modification in prior art CN120025563A According to prior art CN120025563A, except that the pig gelatin is replaced with fish gelatin in equal amount, the rest of the conditions and steps remain unchanged to prepare the fish gelatin system for control. As shown in Table 3, the melting temperature, tensile strength and elongation at break of fish gelatin gels added with chitosan or carrageenan are lower than those of the system added with sodium carboxymethyl cellulose. This is mainly due to the unique structural advantages of sodium carboxymethyl cellulose. Its anionic properties help to maintain the compatibility and uniformity of the system, and the rich hydroxyl and carboxyl groups in the molecular chain can synergistically build a strong hydrogen bond crosslinking network with tannic acid, thereby significantly improving the thermal stability and mechanical properties of the gel. In contrast, chitosan is prone to charge aggregation in the system, resulting in poor structural uniformity; while the gel formation of carrageenan depends on specific ions such as potassium and calcium, and lacks the corresponding ionic environment in the system of the present application, so it cannot achieve the same enhancement effect as sodium carboxymethyl cellulose. Figure 10 As shown in Table 3, the melting temperature, tensile strength and elongation at break of fish gelatin gels added with chitosan or carrageenan are lower than those of the system added with sodium carboxymethyl cellulose. This is mainly due to the unique structural advantages of sodium carboxymethyl cellulose. Its anionic properties help to maintain the compatibility and uniformity of the system, and the rich hydroxyl and carboxyl groups in the molecular chain can synergistically build a strong hydrogen bond crosslinking network with tannic acid, thereby significantly improving the thermal stability and mechanical properties of the gel. In contrast, chitosan is prone to charge aggregation in the system, resulting in poor structural uniformity; while the gel formation of carrageenan depends on specific ions such as potassium and calcium, and lacks the corresponding ionic environment in the system of the present application, so it cannot achieve the same enhancement effect as sodium carboxymethyl cellulose.

[0064] The above provided examples are not intended to limit the scope encompassed by the present application, and the described steps are not intended to limit the execution order thereof. Those skilled in the art can make obvious improvements to the present application in combination with existing common knowledge, which also falls within the protection scope defined by the claims of the present application.

Claims

1. A method for improving the thermal stability of fish gelatin gel by polyphenol-poly saccharide synergy, characterized in that, The method comprises the following steps: (1) mixing fish gelatin, sodium carboxymethyl cellulose, tannic acid and water, stirring and mixing to obtain a mixed system; (2) placing the mixed system in a low-temperature environment and standing to form a stable three-dimensional gel network.

2. The method of claim 1, wherein, The concentration of tannic acid in the mixed system is 0.02 wt%-0.06 wt%.

3. The method of claim 1, wherein, The concentration of sodium carboxymethyl cellulose in the mixed system is 0.45 wt%-0.55 wt%.

4. The method of claim 1, wherein, The concentration of fish gelatin in the mixed system is 14 wt%-16 wt%.

5. The method of claim 1, wherein, Step (1) specifically comprises: First, prepare a fish gelatin solution and a sodium carboxymethyl cellulose solution; then mix deionized water, tannic acid and the sodium carboxymethyl cellulose solution; finally, add the fish gelatin solution, mix and quickly stir to make the solution uniform, thereby obtaining the mixed system.

6. The method of claim 1, wherein, The stirring condition in step (1) is: stirring at a speed of 300-500 rpm for 8-12 min at 45-55℃.

7. A heat-stable fish gelatin gel prepared by the method of any one of claims 1-6.

8. The use of the heat-stable fish gelatin gel of claim 7 in 3D printing.

9. Use according to claim 8, characterized in that, The model layer thickness of 3D printing is set to 0.5-1.5 mm, the printing filling density is set to 75%-85%, the printing environment temperature is 18-22℃, the printing nozzle diameter is 1.1-1.3 mm, the material extrusion rate is 14-16 mm / s, and the nozzle moving rate is 19-21 mm / s.

10. The 3D printing product obtained by the use of claim 9.

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