Food preservation gel and method of preparation
By preparing a hydrogel composed of gelatin, tamarind polysaccharide, and xanthan gum, which absorbs available chlorine, the problem of insufficient sterilization ability of slightly acidic electrolyzed water in non-static processes is solved, thus achieving long-term food preservation and mechanical protection during transportation.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- KUNMING UNIV OF SCI & TECH
- Filing Date
- 2024-03-06
- Publication Date
- 2026-05-08
AI Technical Summary
The reason why slightly acidic electrolyzed water cannot be effectively used in food preservation is that it cannot maintain its bactericidal ability in non-static processes and is prone to causing mechanical damage to food.
A hydrogel composed of gelatin, tamarind polysaccharide, and xanthan gum was prepared, with glutaraldehyde as the crosslinking agent. After the gel was formed, it was immersed in slightly acidic electrolyzed water to absorb available chlorine, thus forming a food preservation gel for the preservation of fruits, vegetables, meat, and seafood.
Extend the shelf life of food, reduce mechanical damage during transportation, and improve preservation.
Smart Images
Figure CN117882768B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of food preservation technology, specifically to a food preservation gel and its preparation method. Background Technology
[0002] Slightly acidic electrolyzed water (SAEW) contains available chlorine (HClO), which can destroy the cell membranes of microorganisms, causing intracellular substances to leak out and leading to the death of microorganisms. This effectively delays the deterioration of their nutritional quality and thus has a broad-spectrum bactericidal effect.
[0003] Compared with traditional chemical preservatives, this technology has the advantages of convenient preparation, low cost, stable storage, no pollution and no residue, and therefore has a wide range of applications in the preservation of fruits, vegetables and other fresh produce.
[0004] Slightly acidic electrolyzed water is fluid, and its available chlorine is easily affected by external environmental factors such as light and storage conditions, causing it to lose its bactericidal ability. As a result, it can only be used to preserve stored food, and cannot be used to preserve food during production, transportation and sales. Summary of the Invention
[0005] The purpose of this invention is to provide a food preservation gel and its preparation method. The hydrogel, prepared by using a specific ratio of gelatin, tamarind polysaccharide, and xanthan gum, allows slightly acidic electrolyzed water to be stored within it, thereby effectively extending the shelf life of food by utilizing the bactericidal effect of the slightly acidic electrolyzed water. At the same time, by utilizing its gel morphology, it can be made into a hydrogel pad, which can reduce mechanical damage to food during transportation and further improve the preservation effect.
[0006] To address the above problems, a first aspect of the present invention provides a method for preparing a food preservation gel, comprising:
[0007] Prepare a gel solution, wherein the gel solution is a mixed solution of gelatin, tamarind polysaccharide and xanthan gum;
[0008] The gel solution is uniformly mixed with the crosslinking agent solution to carry out a crosslinking reaction, thereby forming a gel.
[0009] The gel is immersed in slightly acidic electrolyzed water to absorb available chlorine.
[0010] Preferably, the crosslinking agent is glutaraldehyde; the mass content of the crosslinking agent is 2-3%, and the volume is 10 mL;
[0011] Preferably, the mass content of the gel solution is 8.5%-15%.
[0012] Preferably, the crosslinking temperature of the crosslinking reaction is 50℃-60℃, and the crosslinking time is 1-1.5 hours.
[0013] Preferably, the gel soaking time is 0.5-2 hours.
[0014] Preferably, the effective chlorine concentration of the slightly acidic electrolyzed water is 60 mg·L⁻¹. -1 .
[0015] A second aspect of the present invention provides a food preservation gel prepared using the method described above.
[0016] A third aspect of the present invention provides a use of a food preservation gel, wherein the food preservation gel prepared by the above method is used for the preservation of fruits, vegetables, meat and seafood.
[0017] The above-mentioned technical solution of the present invention has the following beneficial technical effects: the hydrogel prepared by gelatin, tamarind polysaccharide and xanthan gum in a specific ratio allows slightly acidic electrolyzed water to be stored in the hydrogel, slowing down the decomposition rate of slightly acidic electrolyzed water, thereby effectively extending the shelf life of food by utilizing the bactericidal effect of slightly acidic electrolyzed water; at the same time, by utilizing its gel morphology, it can be made into a hydrogel pad, which can reduce the mechanical damage to food during transportation and further improve the preservation effect. Attached Figure Description
[0018] Figure 1a This is a schematic diagram comparing the swelling coefficients of gels prepared with different components;
[0019] Figure 1b This is a schematic diagram comparing the water retention rates of gels prepared with different components;
[0020] Figure 2a This is a schematic diagram comparing the elasticity of gels prepared with different components;
[0021] Figure 2b This is a schematic diagram comparing the hardness of gels prepared with different components;
[0022] Figure 3 This is a schematic diagram comparing the effective chlorine concentration absorption of gels prepared with different components. Detailed Implementation
[0023] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments and the accompanying drawings. It should be understood that these descriptions are merely exemplary and not intended to limit the scope of the invention. Furthermore, descriptions of well-known structures and techniques are omitted in the following description to avoid unnecessarily obscuring the concept of the invention.
[0024] Fruits and vegetables, as well as fresh produce, are susceptible to microbial contamination and oxidation when their internal structures are exposed due to mechanical damage or cutting, leading to a decline in quality and a deterioration in taste. Traditional preservation methods, such as sealing with plastic wrap or plastic bags, or refrigeration, often provide only limited preservation effects and cannot retain the moisture and nutrients of fruits and vegetables for an extended period.
[0025] Immersing fruits, vegetables, and fresh foods in slightly acidic electrolyzed water can extend their shelf life, but this method is not suitable for non-static processes such as transportation. Therefore, this invention achieves food preservation by storing slightly acidic electrolyzed water in a gel, releasing available chlorine during transportation.
[0026] The first embodiment of the present invention provides a method for preparing a food preservation gel, comprising the following steps:
[0027] Step S1: Prepare a gel solution, which is a mixed solution of gelatin, tamarind polysaccharide and xanthan gum;
[0028] Step S2: Mix the gel solution and the crosslinking agent solution evenly to carry out the crosslinking reaction and form a gel;
[0029] Step S3: Soak the gel in slightly acidic electrolyzed water to absorb available chlorine.
[0030] Gelatin is a food additive with excellent gelling properties. It is a single-chain protein obtained by hydrolyzing proteins extracted from animal bones and skin. It has good biocompatibility and degradability and can be compounded with alkaline or acidic substrates.
[0031] Xanthan gum is an acidic polysaccharide produced by fermenting corn starch. It has extremely high water retention, chemical stability, and thermal stability, which can lock in moisture and thus ensure that the gel can be used for a long time.
[0032] Tamarind polysaccharide, extracted from the tamarind plant, is a natural high-molecular-weight neutral polysaccharide with antioxidant properties. It is covalently linked with gelatin and xanthan gum to form a complex gel system. This gel system absorbs slightly acidic electrolyzed water through the pores between the gel bonds, increasing the effective chlorine concentration.
[0033] The gel of this invention not only has good water retention and antioxidant properties, but when used in conjunction with slightly acidic electrolyzed water, it can also inhibit free radicals generated on the surface of fruits, vegetables and meat, inhibit oxidation reactions, and further maintain the color, taste and nutritional value of fruits and vegetables.
[0034] Specifically, the gel solution contains 4-10% gelatin, 0.5-2% tamarind polysaccharide, 1-3% xanthan gum, 3% crosslinking agent, and the remainder is purified water.
[0035] Glutaraldehyde is preferred as a crosslinking agent because it has relatively stable C=O covalent bonds. During the later stages of crosslinking, the O atoms in the C=O covalent bonds are less likely to be replaced, resulting in a more stable gel system. The crosslinking reaction is controlled at 50℃-60℃, and the optimal crosslinking time is 1 hour to ensure that the gel does not dehydrate or fail to form a gel.
[0036] Finally, the prepared gel was soaked in slightly acidic electrolyzed water for 1.5 hours to fully absorb available chlorine.
[0037] The gel system in this embodiment does not require degassing during preparation, thereby increasing the number of pores, which is beneficial for the storage of slightly acidic electrolyzed water. At the same time, the use of tamarind polysaccharide to compound gelatin and xanthan gum not only gives the prepared gel excellent elasticity and mechanical properties, but also increases the effective chlorine concentration in the gel.
[0038] The ability of the gel prepared in this invention to absorb slightly acidic electrolyzed water is verified by measuring the effective chlorine concentration.
[0039] Example 1:
[0040] 1.4g of gelatin, 0.1g of tamarind polysaccharide and 0.5g of xanthan gum were dissolved in 20mL of water in sequence to obtain a gel solution;
[0041] After dissolving, add 1 mL of 3% glutaraldehyde solution to the gel solution, pour the mixed solution into a mold, and crosslink at 50°C for 1 hour to form a gel;
[0042] The gel was soaked in slightly acidic electrolyzed water for 1.5 hours, then removed and placed in a beaker containing 10 mL of pure water for slow release of available chlorine over 20 minutes. After the release, the gel was removed, and the available chlorine concentration in the beaker was measured.
[0043] Example 2:
[0044] Dissolve 2.0g gelatin, 0.1g tamarind polysaccharide and 0.6g xanthan gum in 20mL of water. After dissolution, add 1mL of 3% glutaraldehyde solution to the solution. Pour the mixture into a mold and crosslink at 50℃ for 1h. Other steps are the same as in Example 1.
[0045] Example 3:
[0046] Dissolve 1.6g gelatin, 0.2g tamarind polysaccharide and 0.4g xanthan gum in 20mL of water. After dissolving, add 1mL of 3% glutaraldehyde solution to the solution. Pour the mixture into a mold and crosslink at 50℃ for 1h. Other steps are the same as in Example 1.
[0047] Comparative Example 1:
[0048] The difference in Example 1 is that tamarind polysaccharide and xanthan gum are not added; otherwise, they are the same as in Example 1.
[0049] Comparative Example 2:
[0050] The difference from Example 1 is that xanthan gum is not added; otherwise, it is the same as Example 1.
[0051] Comparative Example 3:
[0052] The difference from Example 1 is that tamarind polysaccharide is not added; otherwise, it is the same as Example 1.
[0053] Table 1 shows a comparison of the components of each embodiment:
[0054] Table 1 Comparison of components
[0055]
[0056] Test 1: Swelling coefficient and water retention coefficient:
[0057] Figure 1a and Figure 1b The swelling coefficient and water retention coefficient of the gels prepared in each example in Table 1 are shown respectively. The letters indicate the multiple comparison level (p < 0.05). Specifically,
[0058] After soaking for 24 hours, remove the gel, wipe off the surface moisture, weigh it, and test the swelling coefficient. The calculation formula is as follows:
[0059]
[0060] The soaked gel was removed and dried at 45℃ for 24 hours. The water retention coefficient was then tested, and the calculation formula is as follows:
[0061]
[0062] Among them, W s and W d These represent the weights of the composite hydrogel in its swollen and dried states, respectively.
[0063] Figure 1a In the figure, the top three coefficients of swelling, from highest to lowest, are D, B, and E;
[0064] Figure 1b Among them, the top three water retention coefficients from high to low are D, B, and C;
[0065] In summary, B and D represent the best examples of swelling and water retention in the experimental and control groups, respectively. Due to the properties of gelatin, it can keep the surface of fruits and vegetables moist and prevent them from dehydrating.
[0066] Under the same gelatin content, A and D showed different swelling and water retention properties due to the addition of tamarind polysaccharide and xanthan gum.
[0067] Compared with E and F, A and F, under the same gelatin mass content, the addition of a single component can lead to a decrease in water absorption performance.
[0068] Test 2: Elasticity and Hardness
[0069] The gels from both the experimental and control groups were prepared into cylindrical shapes, and their texture was measured using a texture analyzer (TA.XT Plus, UK).
[0070] 1. Full Texture TPA Experiment: Probe was P / 75; parameters were set as follows: speed before test 1 mm / s, test speed 0.5 mm / s, speed after test 10 mm / s, trigger force 5 g. The test was repeated 3 times to determine the overall hardness of the gel.
[0071] 2. Puncture test: The probe is P / 2; the parameters are set as follows: speed before test 2mm / s, test speed 1mm / s, speed after test 10mm / s, puncture distance 20.00mm, trigger force 5g; repeat the test 3 times to determine the overall elasticity of the gel.
[0072] Figure 2a and Figure 2b The elasticity and hardness of the gels prepared in each embodiment in Table 1 are shown respectively. As can be seen from A and B, increasing the gelatin content will simultaneously reduce the elasticity of the gel.
[0073] As shown in A and E, the addition of xanthan gum did not significantly change the elasticity of the gel, but it did increase its hardness. In applications such as transportation, a gel pad that balances good elasticity and hardness can reduce damage to fruits and vegetables caused by bumps during transport.
[0074] Test 3: Available Chlorine Concentration
[0075] Take a 1×1×1cm gel and immerse it in slightly acidic electrolyzed water (initial concentration 60 mg·L⁻¹). -1 After 1.5 hours, remove the gel, blot off any remaining SAEW residue with filter paper, and place it in a 10 mL beaker. Immerse for 20 minutes and measure the effective chlorine concentration. Each experiment was repeated in triplicate. The measuring instrument used was HANNA Instruments, Inc. HI9771-11. Results are as follows: Figure 3 As shown, A absorbs the highest effective chlorine concentration.
[0076] The hydrogel was comprehensively scored according to Figure 1-3, with swelling coefficient, water retention rate, elasticity and hardness each accounting for 10% of the total score, and effective chlorine concentration accounting for 60% of the total score. The scores for each example were ranked, with the first place receiving 6 points, the sixth place receiving 1 point, and so on.
[0077] Table 2. Comprehensive scores of the physicochemical properties of hydrogels prepared in different embodiments
[0078] Example swelling coefficient Water retention rate elasticity hardness Available chlorine concentration Total Score A 2 3 5 6 6 5.2 B 5 5 1 1 5 4.2 C 3 4 4 4 4 3.9 D 6 6 2 3 3 3.5 E 4 2 6 5 2 2.9 F 1 1 3 2 1 1.3
[0079] As shown in Table 2, the overall scores of Examples 1-3 are all higher than those of Comparative Examples 4-6 (p<0.05), and the overall score of Example 1 is much higher than that of the other examples (p<0.05). Therefore, the gel prepared by the present invention has good preservation function and is also suitable for transportation.
[0080] The second embodiment of the present invention provides a food preservation gel, which is prepared by the method of the first embodiment.
[0081] The third embodiment of the present invention provides a use for a food preservation gel. Specifically, after the gel solution is prepared, it is spread evenly in a mold. After the gel is formed, it is removed from the mold to obtain a gel pad. The gel pad is then placed in a transport box for the preservation of fruits, vegetables, meat and seafood.
[0082] It should be understood that the specific embodiments described above are merely illustrative or explanatory of the principles of the invention and do not constitute a limitation thereof. Therefore, any modifications, equivalent substitutions, improvements, etc., made without departing from the spirit and scope of the invention should be included within the protection scope of the invention. Furthermore, the appended claims are intended to cover all variations and modifications falling within the scope and boundaries of the appended claims, or equivalent forms of such scope and boundaries.
Claims
1. A method for preparing a food preservation gel, characterized in that, include: Prepare a gel solution, wherein the gel solution is a mixed solution of gelatin, tamarind polysaccharide and xanthan gum; The gel solution is uniformly mixed with the crosslinking agent solution to carry out a crosslinking reaction, thereby forming a gel. The gel is immersed in slightly acidic electrolyzed water to absorb available chlorine; The crosslinking agent is glutaraldehyde; The cross-linking reaction is carried out at a temperature of 50℃-60℃ for 1-1.5 hours. The gelatin content is 4-10% by mass; The mass content of the tamarind polysaccharide is 0.5-2%; The xanthan gum content is 1-3% by mass; The crosslinking agent has a mass content of 2-3% and a volume of 10 mL; The mass content of the gel solution is 8.5%-15%; The gel soaking time is 0.5-2 hours; The effective chlorine concentration of the slightly acidic electrolyzed water is 60 mg·L⁻¹. -1 .
2. A food preservation gel, characterized in that, Prepared using the method described in claim 1.
3. The use of a food preservative gel, characterized in that, The food preservation gel prepared by the method described in claim 1 can be used for the preservation of fruits, vegetables, meat and seafood.