A packaging material for improving oil stability and preparation method thereof

Abstract

The present invention provides a packaging material for improving the stability of oil and fat and a preparation method thereof, belonging to the technical field of composite materials. The preparation method of the packaging material of the present invention comprises the following steps: (1) extracting bamboo shoot crude protein and bamboo shoot cellulose from bamboo shoot processing waste; (2) mixing the bamboo shoot cellulose with a low eutectic solvent, homogenizing after reaction, and obtaining bamboo shoot nanocellulose; (3) mixing the bamboo shoot crude protein, the bamboo shoot nanocellulose, nano-SiO2, konjac glucomannan, and carboxymethyl starch with water, adding chitosan solution and glycerol, cooling, and obtaining the packaging material for improving the stability of oil and fat. The present invention adopts a low eutectic solvent combined with a high-pressure homogenization method to prepare bamboo shoot nanocellulose. The packaging material prepared using the nanocellulose has antioxidant capacity, can improve the stability of oils such as cod liver oil, and extend the shelf life of oil products.

Description

Technical Field

[0001] The present invention relates to the technical field of composite materials, and in particular to a packaging material for improving the stability of oil and fat and a preparation method thereof. Background Art

[0002] One of the increasingly popular supplements in the pet world is fish oil, a source of essential omega-3 fatty acids. Omega-3 fatty acids have a wide range of impacts on the health of cats and dogs. Growing puppies, anxious dogs, and pets with arthritis, heart disease, chronic kidney disease, or inflammatory skin conditions can all benefit from supplementing with omega-3 fatty acids. Fish oil, such as krill oil, is one of the cleanest sources of omega-3 fatty acids for pets.

[0003] More and more pet owners are realizing the tremendous benefits of nutritional and targeted dietary supplements. As Bill Bookout, founder and president of the National Animal Supplement Council (NASC), told Veterinary Practice News a few years ago: One of the fastest-growing categories of pet supplements is fish oil, also known as fish body oil, which is a rich source of essential fatty acids (EFAs), commonly referred to as omega-6 and omega-3 fatty acids. Dogs and cats need both to stay healthy, but omega-3 fatty acids are particularly beneficial. Omega-3 fatty acids include A-linolenic acid (ALA), docosahexaenoic acid (DHA), and eicosapentaenoic acid (EPA), which play a positive role in your pet's overall health in many ways, including: regulating blood clotting activity to help the normal development of the retina and visual cortex; mitigating the harmful effects of allergies and other diseases caused by an overreaction of the immune system; slowing the growth of common yeast infections; and slowing the development and spread of certain cancers. In addition to the above benefits, many clinical studies have shown that omega-3 fatty acids help prevent and treat a variety of diseases such as the cardiovascular system, cognitive function, neurological health, inflammatory skin diseases, kidney disease and osteoarthritis. However, omega-3 fatty acids and fish oil are very easy to oxidize and will be decomposed within a few hours at room temperature, thus losing their special effects. Summary of the invention

[0004] The purpose of the present invention is to provide a packaging material for improving the stability of oils and fats and a preparation method thereof. The present invention adopts a low eutectic solvent combined with a high-pressure homogenization method to prepare bamboo shoot nanocellulose. The packaging material prepared using the nanocellulose has antioxidant capacity, can improve the stability of oils such as cod liver oil, and extend the shelf life of oil products.

[0005] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0006] The present invention provides a method for preparing a packaging material for improving the stability of oil and fat, comprising the following steps:

[0007] (1) Extracting bamboo shoot crude protein and bamboo shoot cellulose from bamboo shoot processing waste;

[0008] (2) mixing the bamboo shoot cellulose with a low eutectic solvent, and homogenizing after the reaction to obtain bamboo shoot nanocellulose;

[0009] (3) After mixing the bamboo shoot crude protein, the bamboo shoot nanocellulose, nano-SiO2, konjac glucomannan, carboxymethyl starch and water, adding chitosan solution and glycerol, cooling, and obtaining the packaging material for improving oil stability.

[0010] Preferably, the method for extracting bamboo shoot crude protein and bamboo shoot cellulose in step (1) comprises the following steps:

[0011] a. The crushed bamboo shoots processing waste is subjected to alkali treatment to obtain an upper liquid and a lower precipitate;

[0012] b. The upper layer of the liquid was treated with acid to obtain a precipitate, which was resuspended, dialyzed and dried to obtain the crude protein of the bamboo shoots;

[0013] c. extracting the lower layer of precipitate, separating the solid from the liquid and drying it to obtain the bamboo shoot cellulose;

[0014] The bamboo shoot processing waste includes bamboo shoot shells and bamboo shoot nodes.

[0015] Preferably, the alkali treatment in step a is to mix the crushed bamboo shoot processing waste with an alkaline solution at a mass ratio of 1:(3-5) at 50-70°C, and treat at a rotation speed of 350-500r / min for 1-3h; the pH of the alkaline solution is 8.5-9.5; and the particle size of the crushed bamboo shoot processing waste is 40-80 mesh.

[0016] Preferably, the acid treatment process in step b is to adjust the pH of the upper layer liquid to 3.8-4.2 with an acid solution, and separate the precipitate; the dialysis molecular weight cutoff is 8000-14000, the dialysis time is 70-80h, the suspension in the dialysis bag is taken, and the precipitate is separated and dried.

[0017] Preferably, the extraction process in step c is to mix the lower layer precipitate with water in a mass ratio of 1:(3-5), adjust the pH to neutral, take the precipitate, mix the precipitate with an organic solvent, and extract; the extraction temperature is 90-100° C., and the time is 3-5 hours;

[0018] The organic solvent is a mixture of toluene and acetone, and the volume ratio of the toluene to the acetone is (1-3):1; the amount of the organic solvent added is based on completely immersing the precipitate.

[0019] Preferably, the preparation method of the low eutectic solvent is: mix betaine and oxalic acid dihydrate in a molar ratio of 1:(2-4), place at 80-95°C until it becomes a colorless liquid, and cool to obtain a low eutectic solvent; the mass ratio of the bamboo shoot cellulose and the low eutectic solvent is 1:(15-25); the particle size of the bamboo shoot cellulose is 60-100 mesh.

[0020] Preferably, the reaction temperature in step (2) is 90-110° C. and the reaction time is 2-6 h; the reaction further includes a washing, freeze-drying and redispersion process, the washing solution includes ethanol and water with a volume fraction of 80-95%, and the redispersion solvent is water; the homogenization pressure is 300-500 MPa and the time is 15-25 min.

[0021] Preferably, the mass ratio of the bamboo shoot crude protein, bamboo shoot nanocellulose, nano-SiO2, konjac glucomannan, carboxymethyl starch, chitosan solution, glycerol and water is (0.5-2):(1-2):(0.2-0.5):(0.5-0.8):(2-4):(0.5-2):(2-4):100; the chitosan solution is a mixture of chitosan and acetic acid solution, and the mass volume ratio of the chitosan to the acetic acid solution is 1g:(100-120)mL.

[0022] Preferably, the mixing temperature in step (3) is 90-100°C; and the temperature when the chitosan and glycerol are added is 40-50°C.

[0023] The present invention also provides a packaging material for improving the stability of oil and fat, which is prepared by the above preparation method.

[0024] The present invention provides a packaging material for improving the stability of oil and fat and a preparation method thereof. The present invention uses a low eutectic solvent combined with high-pressure homogenization to extract and prepare bamboo shoot nanocellulose from bamboo shoot waste, and mixes it with carboxymethyl starch and other ingredients. The mixed solution exhibits shear thinning behavior, and the film-forming liquid is enhanced due to molecular interaction and entanglement. The bamboo shoot nanocellulose nanoparticles are evenly dispersed in the starch matrix, thereby improving the physical and chemical properties of the starch matrix film.

[0025] Compared with the prior art, the present invention has the following technical effects:

[0026] (1) The method for preparing waste bamboo shoot nanocellulose by using a low eutectic solvent combined with high pressure homogenization is green, environmentally friendly, and non-toxic. The low eutectic solvent can also be recycled and reused repeatedly.

[0027] (2) Bamboo shoot processing waste is fully utilized.

[0028] (3) The packaging material of the present invention is green, environmentally friendly, and non-toxic. It can be formed without high temperature heating, which can avoid the damage of high temperature to the effective ingredients of cod liver oil and improve the retention rate of cod liver oil. The materials of the present invention are all edible materials, naturally degradable, and soluble in hot water. The whole package can be directly melted with hot water and mixed with other feeds to improve feeding efficiency.

[0029] (4) The packaging material of the present invention exhibits excellent properties, such as smooth surface, compact cross section, and elongation at break. It also has strong UV resistance and antioxidant capacity, and can improve the antioxidant capacity of cod liver oil, krill oil, and other cod liver oils at room temperature. Compared with the traditional carboxymethyl starch film packaging, the cod liver oil in the packaging material of the present invention shows lower oxidation and is relatively stable during storage at 37°C for 30 days, which has a significant effect on extending the shelf life of cod liver oil. The results show that this type of packaging material has a high application potential in cod liver oil for pet cats. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is the appearance morphology of the bamboo shoot cellulose prepared in Example 1.

[0031] Figure 2 This is the appearance of the packaging material prepared in Example 1.

[0032] Figure 3 This is the appearance morphology of the packaging material prepared in Example 2.

[0033] Figure 4 This is the appearance morphology of the packaging material prepared in Example 3.

[0034] Figure 5 This is the appearance morphology of the packaging material prepared in Comparative Example 1.

[0035] Figure 6 These are the surface and cross-sectional microstructure diagrams of the packaging material of Example 1, where Figure A is the surface structure and Figure B is the cross-sectional structure.

[0036] Figure 7 These are the surface and cross-sectional microstructure diagrams of the packaging material of Example 2, where Figure A is the surface structure and Figure B is the cross-sectional structure.

[0037] Figure 8 These are the surface and cross-sectional microstructure diagrams of the packaging material of Example 9, where Figure A is the surface structure and Figure B is the cross-sectional structure.

[0038] Fig. 9These are the surface and cross-sectional microstructure diagrams of the packaging material of Comparative Example 1, where Figure A is the surface structure and Figure B is the cross-sectional structure.

[0039] Fig.10 This is the cod liver oil sample packaged with the packaging material of Comparative Example 1.

[0040] Fig.11 This is a cod liver oil sample packaged with the packaging material of Example 1.

[0041] Fig.12 This is a cod liver oil sample packaged with the packaging material of Example 2.

[0042] Fig.13 This is the cod liver oil sample packaged with the packaging material of Example 3.

[0043] Fig.14 This is a graph showing the TBARS value test results of each group of cod liver oil samples in Experimental Example 1.

[0044] Fig.15 This is a graph showing the peroxide value test results of each group of cod liver oil samples in Experimental Example 1.

[0045] Fig.16 This is a graph showing the pH value test results of each group of cod liver oil samples in Experimental Example 1.

[0046] Fig.17 In Experimental Example 2, the bamboo shoot nanocellulose was obtained by treating in an oil bath environment at 90°C, 100°C, and 110°C for 4 hours, respectively. The left one is the bamboo shoot nanocellulose obtained by treating in an oil bath environment at 90°C for 4 hours, the middle one is the bamboo shoot nanocellulose obtained by treating in an oil bath environment at 100°C for 4 hours, and the right one is the bamboo shoot nanocellulose obtained by treating in an oil bath environment at 110°C for 4 hours. DETAILED DESCRIPTION

[0047] The technical solutions provided by the present invention are described in detail below in conjunction with the embodiments, but they should not be construed as limiting the protection scope of the present invention.

[0048] Example 1

[0049] This embodiment provides a packaging material for improving the stability of oil and fat, and the specific process is as follows:

[0050] (1) The bamboo shoot processing waste (bamboo shoot shells and bamboo shoot nodes) was cleaned, placed in a cool place to dry, crushed, passed through a 50-mesh sieve, and then placed in a 60°C constant temperature oven for drying. The crushed bamboo shoot processing waste was mixed with NaOH solution (pH 9.0) at a mass ratio of 1:4, stirred at 400 r / min for 2 h at 60°C, and then centrifuged at 4000 rpm for 20 min to obtain the upper liquid and lower precipitate, which were retained separately for later use.

[0051] (2) The upper liquid was adjusted to pH 4.0 with 1.0 mol / L HCl, centrifuged at 10000 rpm for 20 min to obtain a precipitate, and the precipitate was mixed and stirred with 2 times the volume of pure water to form a uniform suspension. The pH of the suspension was adjusted to 7.0 with 1.0 mol / L NaOH. The suspension was loaded into a dialysis bag (molecular weight cutoff of 8000-14000), dialyzed in pure water for 72 h, and the water was changed every 6 h in the middle. After the dialysis, the suspension was centrifuged at 10000 rpm for 20 min, and the precipitate after centrifugation was freeze-dried for 48 h to obtain bamboo shoot crude protein.

[0052] (3) Add water to the lower precipitate in (1) at a mass ratio of 1:4 and stir, adjust the pH to 7.0 with 1.0 mol / L HCl, and then centrifuge to obtain a precipitate. Mix toluene and acetone at a ratio of 2:1 (V / V) to obtain an organic solvent, and place the organic solvent and precipitate in a Soxhlet extractor to completely immerse the precipitate, extract at 95°C for 4h to remove fat and pigment from the precipitate, filter, and dry at 60°C to obtain bamboo shoot cellulose.

[0053] (4) Use a grinder to crush the dried bamboo shoot cellulose and pass it through an 80-mesh sieve. Figure 1 As shown, set aside. Take 1g of crushed bamboo shoot cellulose and add it to 20g of low eutectic solvent (mix betaine / dihydrate oxalic acid in a molar ratio of 1:3, then place it in an oil bath at 90°C until it becomes a colorless liquid, and set aside after cooling at room temperature), and place it in an oil bath at 110°C for 4h. The bamboo shoot cellulose treated in the oil bath was filtered and rinsed with 95% ethanol solution, then filtered and rinsed with pure water until neutral, and freeze-dried. The freeze-dried sample was then dispersed with pure water at a ratio of 1g:100ml, and homogenized at 400MPa for 20min to obtain bamboo shoot nanocellulose.

[0054] (5) Dissolve chitosan in acetic acid solution (1%) at a ratio of 1 g:100 mL to obtain a chitosan solution for standby use. Weigh bamboo shoot crude protein, bamboo shoot nanocellulose, nano-SiO2, konjac glucomannan, carboxymethyl starch, chitosan solution, glycerol, and water at a mass ratio of 1:1:0.4:0.6:3:1:3:100, mix bamboo shoot crude protein, bamboo shoot nanocellulose, nano-SiO2, konjac glucomannan, carboxymethyl starch with 95°C water, stir at 1000 r / min for 30 min until completely dissolved, cool to 45°C, add chitosan solution and glycerol, stir evenly, and cast film on a glass plate to obtain a packaging material for improving oil stability, such as Figure 2 shown.

[0055] Example 2

[0056] The difference between this embodiment and embodiment 1 is that the mass ratio of bamboo shoot crude protein, bamboo shoot nanocellulose, nano-SiO2, konjac glucomannan, carboxymethyl starch, chitosan solution, glycerol, and water is 1:1.5:0.4:0.6:3:1:3:100, and the other operations are the same as those in embodiment 1. The obtained packaging material is as follows Figure 3 shown.

[0057] Example 3

[0058] The difference between this embodiment and embodiment 1 is that the mass ratio of bamboo shoot crude protein, bamboo shoot nanocellulose, nano-SiO2, konjac glucomannan, carboxymethyl starch, chitosan solution, glycerol, and water is 1:2.0:0.4:0.6:3:1:3:100, and the other operations are the same as those in embodiment 1. The obtained packaging material is as follows Figure 4 shown.

[0059] Comparative Example 1

[0060] The difference between this comparative example and Example 1 is that bamboo shoot nanocellulose is omitted, and other operations are the same as those in Example 1. The obtained packaging material is as follows Figure 5 shown.

[0061] Test Example 1

[0062] This test example explores the effect of bamboo shoot nanocellulose (NC) content on the properties of packaging materials. The packaging materials prepared in Examples 1 to 3 and Comparative Example 1 were used as samples for testing. The specific process is as follows:

[0063] 1. Surface and cross-sectional microstructure

[0064] The surface and cross-sectional microstructures of the packaging materials of Examples 1 to 3 and Comparative Example 1 were observed using a scanning electron microscope (SEM). The test results are as follows: Figures 6 to 9 As shown. Among them, Figure 6 The surface (A) and cross-sectional microstructure (B) of the packaging material of Example 1, Figure 7 The surface (A) and cross-sectional microstructure (B) of the packaging material of Example 2, Figure 8 The surface (A) and cross-sectional microstructure (B) of the packaging material of Example 3, Fig. 9 The surface (A) and cross-sectional microstructure (B) of the packaging material of Comparative Example 1.

[0065] from Figures 6 to 9It can be seen that the packaging material without NC addition (Comparative Example 1) shows a typical uniform structure of carboxymethyl starch film without pores. In the carboxymethyl starch / NC packaging materials (Examples 1-3), some cracks were observed, indicating slight delamination. This behavior may be due to the fact that the addition of NC increases the surface hydrophobicity of the film and reduces its interfacial interaction with the NC matrix. The cross-sectional SEM image of the carboxymethyl starch / NC film shows that NC has been fully incorporated into the composite material. From Figures 6 to 8 It can be seen that by incorporating NC into the carboxymethyl starch matrix, the surface becomes uneven and rough, and the NC part aggregates and is tightly bound in the carboxymethyl starch / NC film matrix. When the amount of NC added is increased, it causes the NC and carboxymethyl starch matrix to aggregate, and the film surface becomes rougher.

[0066] 2. Mechanical properties

[0067] The tensile strength, elongation at break and Young's modulus of the packaging materials of Examples 1 to 3 and Comparative Example 1 were tested. The test results are shown in Table 1.

[0068] Table 1 Mechanical properties of packaging materials

[0069] sample Tensile strength(MPa) Elongation at break (%) Young's modulus (MPa) Comparative Example 1 4.28±0.13b 53.32±2.67d 19.46±1.12a Example 1 4.31±0.94a 50.10±1.97a 21.97±1.89b Example 2 4.99±0.47c 37.99±2.15c 35.26±2.02d Example 3 4.92±0.25e 46.06±2.93a 27.71±1.86b

[0070] As can be seen from Table 1, compared with Comparative Example 1, a significant increase in Young's modulus was observed in the samples of Examples 1 to 3, and when the content of NC increased, the tensile strength was between 4.31 and 4.99 MPa. When the content of NC increased to a certain extent, such as in Example 3, the chance of aggregation increased, the tensile strength and Young's modulus decreased compared with Example 2, and the elongation at break increased compared with Example 2. Therefore, the packaging material prepared in Example 2 has the highest mechanical properties.

[0071] 3. Improvement of cod liver oil stability

[0072] The packaging materials of Examples 1 to 3 and Comparative Example 1 were cut into 6 cm × 12 cm sizes, folded in half, and sealed with a heat sealer at 110° C. for 9 seconds. After the two sides were sealed, 5 ml of cod liver oil was poured from the opening, and the opening was sealed with a heat sealer. The sealed samples of Comparative Example 1 and Examples 1 to 3 were named A, B, C, and D, respectively. The shapes of the cod liver oil packaged with the packaging materials of Comparative Example 1 and Examples 1 to 3 are as follows: Figures 10 to 13 shown. Fig.10 This is the cod liver oil sample packaged with the packaging material of Comparative Example 1. Fig.11 This is a cod liver oil sample packaged with the packaging material of Example 1, Fig.12 This is the cod liver oil sample packaged with the packaging material of Example 2, Fig.13 This is the cod liver oil sample packaged with the packaging material of Example 3.

[0073] The cod liver oil of each group was placed at room temperature for 10 days, and samples were taken every two days to test the TBARS value, peroxide value and pH value of the cod liver oil. Figures 14 to 16 shown. Fig.14 The TBARS value test results of each group of cod liver oil samples are shown in Figure 2. Fig.15 The peroxide value test results of each group of cod liver oil samples are shown in Figure 2. Fig.16 These are the pH test results of each group of cod liver oil samples.

[0074] from Fig.14 It can be seen that the TBARS values ​​of all samples continued to increase throughout the storage period. Compared with the other groups, the TBARS value of the sample of Comparative Example 1 showed a sharp upward trend before the 8th day, and then showed a downward trend before the 10th day of storage, which may be attributed to the main production of MDA and its possible degradation through the increase in storage period. The intensity and speed of TBARS formation and decomposition in the samples of Examples 1 to 3 were lower than those of the sample of Comparative Example 1, and the degree of change in the TBARS value of the sample of Example 2 was the smallest (p≤0.05).

[0075] from Fig.15 It can be seen that the peroxide value of the sample of Comparative Example 1 increased from 0.051 to 0.185 after 8 days of storage at room temperature, and then decreased to 0.143 meq O2 / kg fat after 10 days of storage at room temperature. During the entire storage period, the peroxide production of the cod liver oil of Example 2 decreased most significantly (p≤0.05).

[0076] from Fig.16 It can be seen that the pH value of the sample of Comparative Example 1 increases during storage. Compared with Comparative Example 1, the pH value of the sample of Example 2 increases less.

[0077] In summary, the packaging material of Example 2 has the best packaging performance.

[0078] Test Example 2

[0079] In the process of developing packaging materials for improving oil stability, the present invention also studied the oil bath temperature and processing time in the preparation process of bamboo shoot nanocellulose. The specific process is as follows:

[0080] The oil bath temperature was set to 90°C, 100°C, and 110°C, the treatment time was set to 2, 4, and 6 h, and an orthogonal experiment was set to prepare bamboo shoot nanocellulose according to the method of steps (1) to (4) of Example 1. The yield of bamboo shoot nanocellulose was calculated according to the following formula, and the calculation results are shown in Table 2.

[0081] Bamboo shoot nanocellulose yield = bamboo shoot nanocellulose (mg) / bamboo shoot cellulose (mg) × 100%

[0082] Table 2 The yield of bamboo shoot nanocellulose under different conditions

[0083]

[0084]

[0085] As can be seen from Table 2, the yield of bamboo shoot nanocellulose is the highest when treated at 110°C for 4 h. Among them, the bamboo shoot nanocellulose prepared by treating at 90°C, 100°C, and 110°C in an oil bath environment for 4 h has the following morphology: Fig.17 As shown, the left side is 90°C / 4h, the middle is 100°C / 4h, and the right side is 110°C / 4h.

[0086] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for preparing a packaging material for improving the stability of oil, characterized in that: The steps include: (1) Extracting bamboo shoot crude protein and bamboo shoot cellulose from bamboo shoot processing waste; (2) mixing the bamboo shoot cellulose with a low eutectic solvent, and homogenizing after the reaction to obtain bamboo shoot nanocellulose; (3) mixing the bamboo shoot crude protein, the bamboo shoot nanocellulose, nano-SiO2, konjac glucomannan, carboxymethyl starch and water, adding chitosan solution and glycerol, and cooling to obtain the packaging material for improving oil stability; The method for extracting bamboo shoot crude protein and bamboo shoot cellulose in step (1) comprises the following steps: a. The crushed bamboo shoots processing waste is subjected to alkali treatment to obtain an upper liquid and a lower precipitate; b. The upper layer of the liquid was treated with acid to obtain a precipitate, which was resuspended, dialyzed and dried to obtain the crude protein of the bamboo shoots; c. extracting the lower layer of precipitate, separating the solid from the liquid and drying it to obtain the bamboo shoot cellulose; The bamboo shoot processing waste includes bamboo shoot shells and bamboo shoot nodes; The acid treatment process in step b is to adjust the pH of the upper layer liquid to 3.8-4.2 with an acid solution, and separate the precipitate; The deep eutectic solvent in step (2) is betaine and oxalic acid dihydrate; The reaction temperature in step (2) is 90-110°C and the reaction time is 2-6 hours; The molecular weight cut-off of the dialysis in step b is 8000-14000Da.

2. The preparation method according to claim 1, characterized in that: The alkali treatment in step a is to mix the crushed bamboo shoot processing waste with an alkaline solution at a mass ratio of 1:(3-5) at 50-70°C, and treat at a speed of 350-500r / min for 1-3h; the pH of the alkaline solution is 8.5-9.5; and the particle size of the crushed bamboo shoot processing waste is 40-80 mesh.

3. The preparation method according to claim 2, characterized in that: The dialysis time is 70 to 80 hours, the suspension in the dialysis bag is taken, and the precipitate is separated and dried.

4. The preparation method according to claim 3, characterized in that: The extraction process of step c is to mix the lower layer precipitate with water in a mass ratio of 1: (3-5), adjust the pH to neutral, take the precipitate, mix the precipitate with an organic solvent, and extract; the extraction temperature is 90-100° C., and the time is 3-5 hours; The organic solvent is a mixture of toluene and acetone, and the volume ratio of the toluene to the acetone is (1-3):1; the amount of the organic solvent added is based on completely immersing the precipitate.

5. The preparation method according to claim 4, characterized in that: The preparation method of the low eutectic solvent is as follows: betaine and oxalic acid dihydrate are mixed in a molar ratio of 1:(2-4), placed at 80-95° C. until it becomes a colorless liquid, and cooled to obtain a low eutectic solvent; the mass ratio of the bamboo shoot cellulose to the low eutectic solvent is 1:(15-25); the particle size of the bamboo shoot cellulose is 60-100 meshes.

6. The preparation method according to claim 5, characterized in that: The reaction in step (2) further includes a washing, freeze-drying and redispersion process, wherein the washing solution includes ethanol and water with a volume fraction of 80 to 95%, and the redispersion solvent is water; the homogenization pressure is 300 to 500 MPa, and the time is 15 to 25 minutes.

7. The preparation method according to claim 6, characterized in that: The mass ratio of the bamboo shoot crude protein, bamboo shoot nanocellulose, nano-SiO2, konjac glucomannan, carboxymethyl starch, chitosan solution, glycerol and water is (0.5-2):(1-2):(0.2-0.5):(0.5-0.8):(2-4):(0.5-2):(2-4):100; the chitosan solution is a mixture of chitosan and acetic acid solution, and the mass volume ratio of the chitosan to the acetic acid solution is 1g:(100-120)mL.

8. The preparation method according to claim 7, characterized in that: The mixing temperature in step (3) is 90-100°C; the temperature when chitosan and glycerol are added is 40-50°C.

9. A packaging material for improving oil stability obtained by the preparation method according to any one of claims 1 to 8.

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