Cellulose derivative anti-oxidation film and preparation method thereof

Abstract

The invention belongs to the field of preparation of food packaging materials, and particularly relates to a cellulose derivative anti-oxidation film and a preparation method thereof as well as a multifunctional packaging material for food preservation. The novel composite membrane is prepared by taking separated whey protein (WPI) and sodium carboxymethyl cellulose (CMC) as raw materials, taking glycerol as a plasticizer and taking tea polyphenol (TP) as an antioxidant and an antibacterial agent, so that the ultraviolet blocking capability, the water vapor blocking capability and the oxidation resistance of the composite membrane are improved.

Description

Technical Field

[0001] This invention belongs to the field of food packaging material preparation, specifically relating to a cellulose derivative antioxidant film and its preparation method, which is a multifunctional packaging material for food preservation. Background Technology

[0002] Currently, oxidized food can lead to problems such as nutrient loss, decreased taste, and microbial growth. Therefore, there is an urgent need to find a safe and effective barrier and antioxidant food packaging to prevent food oxidation. Currently, petroleum-based plastics are the main food packaging materials. The extensive use of petroleum-based plastics severely damages the environment, and non-degradable plastic components accumulate in biological tissues, producing a biomagnification effect through the food chain. Among natural polymer materials, cellulose is abundant, renewable, and environmentally friendly, making it highly promising for food packaging applications. At the same time, using green, biodegradable bio-packaging materials to replace traditional petroleum-based plastic packaging is a current development trend.

[0003] Whey protein isolate (WPI), a byproduct of dairy processing, is widely used as a functional ingredient in the food industry. As a byproduct of cheese and casein production, whey protein isolate exhibits good gelling properties and biocompatibility. However, pure WPI typically displays lower mechanical strength, but this drawback can be mitigated by incorporating other polymers.

[0004] Sodium carboxymethyl cellulose (CMC), as an anionic cellulose derivative, possesses high water solubility, biocompatibility, and biodegradability. These properties make it a subject of extensive research in the field of composite materials for pharmaceutical and food applications.

[0005] Tea polyphenols (TP) are the main potent chemical components in tea. TP possesses excellent water solubility, high antioxidant activity, biocompatibility, and low viscosity, making it suitable for incorporation into various polymers, including polysaccharides, polyvinyl alcohol, and proteins. The use of TP as an active ingredient in materials has spurred the targeted development of numerous biodegradable packaging materials with antioxidant properties.

[0006] Currently, active and intelligent coatings or packaging have been developed by incorporating bioactive compounds. As active coatings or packaging systems, the antioxidant properties of bioactive compounds play a crucial role in extending the shelf life of food. In intelligent coating or packaging systems, bioactive compounds are also used for real-time monitoring of food quality and safety during transportation and storage. For example, anthocyanins from plants have been reported to be used to prepare intelligent packaging that can monitor the freshness of food in real time.

[0007] Furthermore, many existing food packaging films only possess basic packaging functions and lack effective protection for food quality and safety. For example, Zhu developed a polyvinyl alcohol (PVA) / nanocrystalline cellulose (NCC) composite film through physical cross-linking. Spoilage during food storage increases the risk of consuming spoiled food. Summary of the Invention

[0008] The purpose of this invention is to overcome the shortcomings of the prior art and provide a cellulose derivative antioxidant film and its preparation method.

[0009] To achieve the above objectives, the present invention adopts the following technical solution:

[0010] A method for preparing a cellulose derivative antioxidant film, characterized by comprising the following steps:

[0011] 1) Dissolve WPI in deionized water, heat and stir to obtain a WPI solution;

[0012] 2) Dissolve CMC in deionized water, heat and stir to obtain a CMC solution;

[0013] 3) Mix the WPI solution and CMC solution, and heat to react and obtain a mixed solution;

[0014] 4) Add tea polyphenols and glycerin to the mixture in step 3), stir continuously in a water bath, then let it cool naturally to room temperature and stand to eliminate any possible air bubbles;

[0015] 5) Cast the mixture from step 4) into a petri dish and place it in an oven. Once the film is dry, remove it and peel it off.

[0016] In step 1), the ratio of WPI to deionized water is 1-10 g / 100 mL, and the heating temperature is 30-90℃.

[0017] In step 2), the ratio of CMC to deionized water is 1-10 g / 100 mL, and the heating temperature is 30-90℃.

[0018] In step 3), the mass ratio of WPI solution to CMC solution is 1:1 to 2.

[0019] In step 4), the amount of tea polyphenols added is 0.1% to 1% of the mass of the solute in the mixed solution.

[0020] In step 4), the amount of glycerol added is 0-10% of the mass ratio of the solvent.

[0021] In step 4), the water bath temperature is 30–90°C.

[0022] In step 5), the oven temperature is 50-60℃ and the drying time is 24-48h.

[0023] An antioxidant film derived from cellulose is prepared using the method described above.

[0024] The application of the aforementioned cellulose derivative antioxidant film is characterized by its use in multifunctional packaging for food preservation.

[0025] Compared with the prior art, the beneficial effects achieved by the technical solution of this invention are:

[0026] This invention utilizes the electrostatic bonding of the anionic groups of sodium carboxymethyl cellulose and the cationic groups of whey protein isolate, while simultaneously blending tea polyphenols, to prepare a novel antioxidant membrane.

[0027] This invention adds tea polyphenols as an antioxidant, giving the film antioxidant properties, thereby preserving food and reducing health problems caused by consuming spoiled food. Attached Figure Description

[0028] Figure 1 Fourier transform infrared absorption spectra of WPI / CMC&TP-0 and WPI / CMC&TP-10 prepared in Examples 1 and 5 of this invention.

[0029] Figure 2 The UV-Vis transmittance curve of WPI / CMC&TP-3 prepared in Example 3;

[0030] Figure 3 Water vapor transmission rate of WPI / CMC&TP-0, WPI / CMC&TP-1, WPI / CMC&TP-3, WPI / CMC&TP-6, and WPI / CMC&TP-10 prepared in Examples 1-5;

[0031] Figure 4 The 1,1-diphenyl-2-trinitrophenylhydrazine (DPPH) scavenging rates of WPI / CMC&TP-0, WPI / CMC&TP-1, WPI / CMC&TP-3, WPI / CMC&TP-6, and WPI / CMC&TP-10 prepared in Examples 1-5; Detailed Implementation

[0032] To make the technical problems, technical solutions and beneficial effects of the present invention clearer and more understandable, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0033] Comparative Example 1

[0034] The method for preparing a cellulose derivative antioxidant film described in this embodiment includes the following steps:

[0035] Dissolve 1g of sodium carboxymethyl cellulose (CMC-Na) in 100ml of deionized water and stir well to prepare a 1% w / v solution. Then dissolve 8g of whey protein isolate (WPI) in 100ml of deionized water and heat and stir at 45℃ for 30min to prepare an 8% w / v solution.

[0036] Mix 15g of CMC-Na solution with 15g of WPI solution, and add 1g of glycerol and 0% (relative solute mass) of tea polyphenols (TP). Heat and stir the resulting solution at 45℃ for 30min to obtain a film-forming solution.

[0037] The film-forming solution was poured into a petri dish and placed in a 60°C oven to dry for 36 hours to obtain a cellulose derivative antioxidant film, which was named WPI / CMC&TP-0.

[0038] Example 1

[0039] Dissolve 1g of sodium carboxymethyl cellulose (CMC-Na) in 100ml of deionized water and stir well to prepare a 1% w / v solution. Then dissolve 8g of whey protein isolate (WPI) in 100ml of deionized water and heat and stir at 45℃ for 30min to prepare an 8% w / v solution.

[0040] Mix 15g of CMC-Na solution with 15g of WPI solution, and add 1g of glycerol and 0.1% (relative solute mass) of tea polyphenols (TP). Heat and stir the resulting solution at 45℃ for 30min to obtain a film-forming solution.

[0041] The film-forming solution was poured into a petri dish and placed in a 60°C oven to dry for 36 hours to obtain a cellulose derivative antioxidant film, which was named WPI / CMC&TP-1.

[0042] Example 2

[0043] Dissolve 1g of sodium carboxymethyl cellulose (CMC-Na) in 100ml of deionized water and stir well to prepare a 1% w / v solution. Then dissolve 8g of whey protein isolate (WPI) in 100ml of deionized water and heat and stir at 45℃ for 30min to prepare an 8% w / v solution.

[0044] Mix 15g of CMC-Na solution with 15g of WPI solution, and add 1g of glycerol and 0.3% (relative solute mass) of tea polyphenols (TP). Heat and stir the resulting solution at 45℃ for 30min to obtain a film-forming solution.

[0045] The film-forming solution was poured into a petri dish and placed in a 60°C oven to dry for 36 hours to obtain a cellulose derivative antioxidant film, which was named WPI / CMC&TP-3.

[0046] Example 3

[0047] Dissolve 1g of sodium carboxymethyl cellulose (CMC-Na) in 100ml of deionized water and stir well to prepare a 1% w / v solution. Then dissolve 8g of whey protein isolate (WPI) in 100ml of deionized water and heat and stir at 45℃ for 30min to prepare an 8% w / v solution.

[0048] Mix 15g of CMC-Na solution with 15g of WPI solution, and add 1g of glycerol and 0.5% (relative solute mass) of tea polyphenols (TP). Heat and stir the resulting solution at 45℃ for 30min to obtain a film-forming solution.

[0049] The film-forming solution was poured into a petri dish and placed in a 60°C oven to dry for 36 hours to obtain a cellulose derivative antioxidant film, which was named WPI / CMC&TP-5.

[0050] Example 4

[0051] Dissolve 1g of sodium carboxymethyl cellulose (CMC-Na) in 100ml of deionized water and stir well to prepare a 1% w / v solution. Then dissolve 8g of whey protein isolate (WPI) in 100ml of deionized water and heat and stir at 45℃ for 30min to prepare an 8% w / v solution.

[0052] Mix 15g of CMC-Na solution with 15g of WPI solution, and add 1g of glycerol and 0.5% (relative solute mass) of tea polyphenols (TP). Heat and stir the resulting solution at 45℃ for 30min to obtain a film-forming solution.

[0053] The film-forming solution was poured into a petri dish and placed in a 60°C oven to dry for 36 hours to obtain a cellulose derivative antioxidant film, which was named WPI / CMC&TP-5.

[0054] Tests and Results:

[0055] Figure 1 The Fourier transform infrared absorption spectra of WPI / CMC&TP-0 and WPI / CMC&TP-10 prepared in Comparative Example 1, Example 4 are shown.

[0056] Depend on Figure 1 It can be seen that the absorption peak of WPI / CMC&TP-10 is at 3000 cm⁻¹. -1 and 3650cm -1The broadband observed corresponds to the stretching of the -OH group; the CH asymmetric stretching vibration is approximately 2918 cm⁻¹. -1 At 2879 cm⁻¹, CH symmetrical stretching vibration occurs. -1 The COO peak is at 1631 cm⁻¹. -1 -CH2 bending vibration at 1404 cm⁻¹ -1 The stretching vibrations of CO and COC are located at 1232 cm⁻¹. -1 and 1105cm -1 The bending vibration of -OH and the stretching vibration of CO are located at 1319 cm⁻¹. -1 and 1034cm -1 Location; the CH bending vibration of the protein at 920 cm⁻¹ -1 Place.

[0057] Figure 2 The UV-Vis transmittance curve of WPI / CMC&TP-3 prepared in Example 2 is shown.

[0058] Figure 2 The results show that the composite film almost completely absorbs short-wave sterilization ultraviolet UVC (200-280 nm), while the transmittance of medium-wave erythema-inducing ultraviolet UVB (280-320 nm) is only 1.6%, demonstrating the excellent ultraviolet blocking performance of the composite film. This is mainly because WPI is rich in aromatic amino acids (such as phenylalanine, tyrosine, and tryptophan), which have strong ultraviolet absorption capabilities. In the visible light region (400–760 nm), the composite film exhibits high transmittance.

[0059] Figure 3 The water vapor transmission rates of WPI / CMC&TP-0, WPI / CMC&TP-1, WPI / CMC&TP-3, WPI / CMC&TP-6, and WPI / CMC&TP-10 prepared in Comparative Example 1 and Examples 1-4 are shown.

[0060] Figure 3 The results show that as the TP content increases, the WVP of the film first increases and then decreases, with the highest value of WPI / CMC&TP3 being 366 g / m. 2 ×24h, with the lowest value of WPI / CMC&TP4 being 331g / m 2 ×24h. Due to the high hydroxyl content and hydrophilicity of TP, the WVP value of WPI / CMC&TP10 films increased slightly. Overall, the WVP of all films did not change significantly, indicating that all films have moisture-proof capabilities.

[0061] Figure 4The DPPH scavenging rates of WPI / CMC&TP-0, WPI / CMC&TP-1, WPI / CMC&TP-3, WPI / CMC&TP-6, and WPI / CMC&TP-10 prepared in Comparative Example 1 and Examples 1-4 are shown. The results indicate that the composite membrane WPI / CMC&TP-6 exhibits the highest free radical scavenging rate of 23.37%, demonstrating excellent antioxidant properties. This is attributed to the presence of unpaired electrons in tea polyphenols, which can donate electrons and hydrogen to free radicals, thereby scavenging reactive oxygen species. These results also confirm the effectiveness of this antioxidant packaging and its suitability for food preservation.

[0062] In summary, the cellulose derivative antioxidant film of this invention is prepared by reacting WPI and CMC as raw materials, glycerol as a plasticizer, and TP as an antioxidant. The prepared composite film exhibits excellent ultraviolet shielding performance. This composite material has the ability to block water vapor and also possesses a certain degree of antioxidant capacity.

[0063] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for producing an antioxidant film of a cellulose derivative, characterized by, The method comprises the following steps: 1) dissolving WPI in deionized water, heating and stirring to obtain a WPI solution; 2) dissolving CMC in deionized water, heating and stirring to obtain a CMC solution; 3) mixing the WPI solution and the CMC solution, heating and reacting to obtain a mixed solution; 4) adding tea polyphenol and glycerol to the mixed solution of step 3), continuously stirring in a water bath environment, and then naturally cooling to room temperature and standing to eliminate possible air bubbles; 5) casting the mixed solution of step 4) in a culture dish, placing it in an oven, taking it out and peeling off after the film is dried.

2. The method for preparing an antioxidant film of a cellulose derivative according to claim 1, characterized by, In step 1), the ratio of WPI to deionized water is 1-10 g / 100 mL, and the heating temperature is 30-90°C.

3. The method for preparing a cellulose derivative antioxidant film according to claim 1, characterized in that, In step 2), the ratio of CMC to deionized water is 1-10 g / 100 mL, and the heating temperature is 30-90°C.

4. The method for preparing a cellulose derivative antioxidant film according to claim 1, characterized in that, In step 3), the mass ratio of the WPI solution to the CMC solution is 1:1-2.

5. The method for preparing a cellulose derivative antioxidant film according to claim 1, characterized in that, In step 4), the addition amount of tea polyphenol is 0.1%-1% of the mass of solutes in the mixed solution.

6. The method for preparing a cellulose derivative antioxidant film according to claim 1, characterized in that, In step 4), the addition amount of glycerol is 0-10% of the mass ratio of the solvent.

7. The method for preparing a cellulose derivative antioxidant film according to claim 1, characterized in that, In step 4), the water bath temperature is 30-90°C.

8. The method for preparing a cellulose derivative antioxidant film according to claim 1, characterized in that, In step 5), the temperature of the oven is 50-60°C, and the drying time is 24-48 h.

9. A cellulose derivative antioxidant film, characterized by: The film is prepared by any one of the preparation methods of claims 1-8.

10. Use of a cellulose derivative antioxidant film according to claim 9, characterized in that: Multifunctional packaging for food preservation.

Images