Preparation method of high-antioxidant color-changeable intelligent active preservative film containing blueberry anthocyanin
By constructing a chitosan/corn starch-based nanocomposite to encapsulate bilberry anthocyanins, the degradation problem of anthocyanins under high temperature and light was solved, the environmental stability and slow-release performance of the film were improved, and long-term preservation and freshness visualization of high-protein aquatic products were achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- NORTHEAST AGRICULTURAL UNIVERSITY
- Filing Date
- 2026-03-04
- Publication Date
- 2026-06-09
Smart Images
Figure CN122167829A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of food preservation technology, specifically relating to the preparation of a highly antioxidant, color-changing, intelligent active preservation film containing bilberry anthocyanins and its application in the preservation of South American white shrimp. Technical Background
[0002] In the field of food preservation, high-protein aquatic products such as shrimp are susceptible to spoilage due to microbial growth and environmental factors (temperature, light, humidity). While traditional plastic packaging materials (such as polyethylene and polypropylene) are widely used due to their low cost and superior performance, their non-degradable nature leads to serious environmental pollution problems. Therefore, in recent years, the trend in food packaging research and development has shifted towards natural, biodegradable materials.
[0003] Chitosan, as the only positively charged natural polysaccharide, possesses a dense structure formed by hydrogen bonds between its hydroxyl and amino groups, endowing films with excellent film-forming properties, oxygen barrier properties, and water retention. Corn starch, due to its high amylose content, offers advantages such as high transparency, strong thermoplasticity, and low cost, and is often combined with chitosan to compensate for the insufficient mechanical properties of single materials. However, traditional composite films still have limitations in terms of antioxidant activity and environmental stability, making it difficult to meet the long-term preservation requirements of highly active ingredients.
[0004] Active packaging technology, which enhances food preservation by introducing functional ingredients (such as antioxidants and antibacterial agents), has become a hot research topic. Anthocyanins, as natural pigments, possess low cost, high safety, and pH-responsive color-changing properties, showing potential in food preservation. However, they are sensitive to environmental factors such as light, heat, and metal ions, and are prone to degradation and fading.
[0005] Nanoencapsulation technology can significantly improve the stability of anthocyanins, with a marked increase in retention rate compared to their free form. Chitosan derivatives (such as carboxymethyl chitosan, CMC) and negatively charged whey protein isolate (WPI) can form nanocarriers through electrostatic interactions, achieving sustained-release protection of active ingredients. However, the encapsulation efficiency, dispersion uniformity, and synergistic mechanisms of anthocyanin nanocomposites in existing technologies still require further investigation.
[0006] This invention innovatively uses bilberry anthocyanins as an antioxidant. Through the interaction of chitosan hydrochloride (CHC) and carboxymethyl chitosan (CMC) and the encapsulation effect of whey protein isolate (WPI), an ACNs-CHC / CMC-WPI nanocomposite is constructed and characterized. The film is then applied to the preservation of white shrimp from South America and characterized. Summary of the Invention
[0007] The purpose of this invention is to address the problem that traditional anthocyanin-containing active films are prone to anthocyanin degradation and active ingredient deactivation under high temperature and light conditions. This invention develops an active preservation film based on a chitosan / corn starch-based nanocomposite, which encapsulates bilberry anthocyanins using electrostatic self-assembly technology, enhancing its environmental stability and slow-release performance. The film's unique pH-responsive characteristics can indicate the spoilage level of meat products in real time, achieving more efficient preservation of high-protein aquatic products (such as shrimp) while providing a visual representation of their freshness. This invention aims to provide a biodegradable food packaging material with excellent mechanical properties, antioxidant capacity, freshness visualization capabilities, and environmental adaptability.
[0008] Technical solution: Preparation of chitosan / corn starch nanocomposite preservation film loaded with bilberry anthocyanins (CTS / Corn-AN film), the specific steps are as follows:
[0009] (1) Extraction and purification of blueberry anthocyanins: 200 g of fresh blueberry pulp was extracted with 60% ethanol solution at 45 °C by ultrasonic extraction for 1 h. After centrifugation (8000 rpm, 15 min) and purification by AB-8 macroporous resin column chromatography, the ethanol was removed by rotary evaporator and the anthocyanin extract was obtained by freeze drying under vacuum.
[0010] (2) Preparation of nanocomposite: 12 mg chitosan hydrochloride (CHC) and 15 mg carboxymethyl chitosan (CMC) were dissolved in deionized water and mixed with 1.25 g of skim whey protein (WPI) aqueous solution (68.5 °C, 2 h). 2 mL of anthocyanin solution (0.60 mg / mL) was added to 30 mL of CHC solution, and after stirring, 10 mL of CMC solution (pH 6.0) was slowly added dropwise. Stirring was continued for 30 min to form a positive and negative charge composite system. Finally, 20 mL of WPI solution was added, and the pH was adjusted to 3.8 with 1 mol / L HCl to obtain ACNs-CHC / CMC-WPI nanocomposite (CHC / CMC mixed solution: WPI solution = 1.5-2.5:1).
[0011] (3) Preparation of different thin films:
[0012] (3.1) Thin films loaded with ACNs-CHC / CMC-WPI nanocomposites
[0013] 1.5 g of chitosan (CS) was dissolved in 0.5% acetic acid solution (40 °C). 2 g of corn starch (CT) was gelatinized in a 95 °C water bath and then cooled to 50 °C, and mixed with the CS solution. 30 wt% glycerol was added as a plasticizer. After ultrasonic treatment (240 W, 28 kHz, 15 min), a nanocomposite solution was added according to a volume ratio of 5:3 between the mixed solution loaded with anthocyanin complex and the ultrasonic mixed film solution. The mixture was poured into a mold and dried (25 °C, 40% RH, 1.5 h). This film is designated as CTS / Corn-AN film.
[0014] (3.2) Films containing free anthocyanins
[0015] 1.5 g of chitosan (CS) was dissolved in 0.5% acetic acid solution (40 °C). 2 g of corn starch (CT) was gelatinized in a 95 °C water bath and then cooled to 50 °C, and mixed with the CS solution. 30 wt% glycerol was added as a plasticizer. After ultrasonic treatment (240 W, 28 kHz, 15 min), free anthocyanin solution was added according to a volume ratio of 5:3 between the free anthocyanin solution and the ultrasonically mixed membrane solution. The mixture was poured into a mold and dried (25 °C, 40% RH, 1.5 h). This film is designated as CTS / Corn-FN film.
[0016] (3.3) Films without anthocyanins
[0017] 1.5 g of chitosan (CS) was dissolved in a 0.5% acetic acid solution (40 °C). 2 g of corn starch (CT) was gelatinized in a 95 °C water bath and then cooled to 50 °C, and mixed with the CS solution. 30 wt% glycerol was added as a plasticizer, and the mixture was ultrasonically treated (240 W, 28 kHz, 15 min), then poured into a mold and dried (25 °C, 40% RH, 1.5 h). This film is designated as CTS / Corn film.
[0018] The beneficial effects of this invention are as follows:
[0019] (1) The film-forming liquid has excellent performance. The mixed solution formed by mixing the loaded anthocyanin nanocomplex solution and the ultrasonic mixed film solution in a specific volume ratio has good leveling properties and coating adaptability.
[0020] (2) The addition of bilberry anthocyanin nanocomposite enhances the physical structure of the film. The film exhibits excellent mechanical, moisture-proof, thermal stability and antioxidant properties, demonstrating good all-round performance and is more suitable for long-term packaging of high-protein aquatic products.
[0021] (3) The membrane has good pH sensitivity and its surface color changes with pH, which can indicate the spoilage process of high-protein aquatic products (such as shrimp) in real time. Attached Figure Description
[0022] Figure 1 The appearance of the different thin films prepared
[0023] Figure 2 To show the changes in antioxidant activity of different films
[0024] Figure 3 The quality changes of shrimp stored at 4℃ for 10 days after different treatments.
[0025] Figure 4 Results of total volatile basic nitrogen determination of shrimp stored at 4℃ for 10 days after different treatments
[0026] Figure 5 Results of determination of thiobarbituric acid reactants in shrimp stored at 4℃ for 10 days after different treatments.
[0027] Figure 6 Results of total bacterial count determination in shrimp stored at 4℃ for 10 days after different treatments. Detailed Implementation
[0028] The present invention will be further illustrated by some specific examples below, but the content of the present invention is not limited to the embodiments described.
[0029] This invention prepared a nanocomposite membrane by adding a blueberry anthocyanin nanocomposite (ACNs-CHC / CMC-WPI) encapsulated with carboxymethyl chitosan (CMC), chitosan hydrochloride (CHC), and whey protein isolate (WPI), and combined it with chitosan and corn starch. The functionality and stability of the anthocyanin-loaded nanocomposite and the anthocyanin-containing membrane were evaluated. Specific Implementation Example 1:
[0031] (1) Extraction and purification of blueberry anthocyanins: 200 g of fresh blueberry pulp was extracted with 60% ethanol solution at 45 °C by ultrasonic extraction for 1 h. After centrifugation (8000 rpm, 15 min) and purification by AB-8 macroporous resin column chromatography, the ethanol was removed by rotary evaporator and the anthocyanin extract was obtained by freeze drying under vacuum.
[0032] (2) Preparation of nanocomposite: 12 mg chitosan hydrochloride (CHC) and 15 mg carboxymethyl chitosan (CMC) were dissolved in deionized water and mixed with 1.25 g of skim whey protein (WPI) aqueous solution (68.5 °C, 2 h). 2 mL of anthocyanin solution (0.60 mg / mL) was added to 30 mL of CHC solution, and after stirring, 10 mL of CMC solution (pH 6.0) was slowly added dropwise. Stirring was continued for 30 min to form a positive and negative charge composite system. Finally, WPI solution was added, and the pH was adjusted to 3.8 with 1 mol / L HCl to obtain ACNs-CHC / CMC-WPI nanocomposite (CHC / CMC mixed solution: WPI solution = 2:1).
[0033] (3) Thin films loaded with ACNs-CHC / CMC-WPI nanocomposites
[0034] 1.5 g of chitosan (CS) was dissolved in 0.5% acetic acid solution (40 °C). 2 g of corn starch (CT) was gelatinized in a 95 °C water bath and then cooled to 50 °C, and mixed with the CS solution. 30 wt% glycerol was added as a plasticizer. After ultrasonic treatment (240 W, 28 kHz, 15 min), a nanocomposite solution was added according to a volume ratio of 5:3 between the mixed solution loaded with anthocyanin complex and the ultrasonic mixed film solution. The mixture was poured into a mold and dried (25 °C, 40% RH, 1.5 h). This film is designated as CTS / Corn-AN film. Specific Implementation Example 2:
[0036] (1) Extraction and purification of blueberry anthocyanins: 200 g of fresh blueberry pulp was extracted with 60% ethanol solution at 45 °C by ultrasonic extraction for 1 h. After centrifugation (8000 rpm, 15 min) and purification by AB-8 macroporous resin column chromatography, the ethanol was removed by rotary evaporator and the anthocyanin extract was obtained by freeze drying under vacuum.
[0037] (2) Preparation of nanocomposite: 12 mg chitosan hydrochloride (CHC) and 15 mg carboxymethyl chitosan (CMC) were dissolved in deionized water and mixed with 1.25 g of skim whey protein (WPI) aqueous solution (68.5 °C, 2 h). 2 mL of anthocyanin solution (0.60 mg / mL) was added to 30 mL of CHC solution, and after stirring, 10 mL of CMC solution (pH 6.0) was slowly added dropwise. Stirring was continued for 30 min to form a positive and negative charge composite system. Finally, WPI solution was added, and the pH was adjusted to 3.8 with 1 mol / L HCl to obtain ACNs-CHC / CMC-WPI nanocomposite (CHC / CMC mixed solution: WPI solution = 2.5:1).
[0038] (3) Thin films loaded with ACNs-CHC / CMC-WPI nanocomposites
[0039] 1.5 g of chitosan (CS) was dissolved in 0.5% acetic acid solution (40 °C). 2 g of corn starch (CT) was gelatinized in a 95 °C water bath and then cooled to 50 °C, and mixed with the CS solution. 30 wt% glycerol was added as a plasticizer. After ultrasonic treatment (240 W, 28 kHz, 15 min), a nanocomposite solution was added according to a volume ratio of 5:3 between the mixed solution loaded with anthocyanin complex and the ultrasonic mixed film solution. The mixture was poured into a mold and dried (25 °C, 40% RH, 1.5 h). This film is designated as CTS / Corn-AN film. Specific Implementation Example 3:
[0041] (1) Extraction and purification of blueberry anthocyanins: 200 g of fresh blueberry pulp was extracted with 60% ethanol solution at 45 °C by ultrasonic extraction for 1 h. After centrifugation (8000 rpm, 15 min) and purification by AB-8 macroporous resin column chromatography, the ethanol was removed by rotary evaporator and the anthocyanin extract was obtained by freeze drying under vacuum.
[0042] (2) Preparation of nanocomposite: 12 mg chitosan hydrochloride (CHC) and 15 mg carboxymethyl chitosan (CMC) were dissolved in deionized water and mixed with 1.25 g of skim whey protein (WPI) aqueous solution (68.5 °C, 2 h). 2 mL of anthocyanin solution (0.60 mg / mL) was added to 30 mL of CHC solution, and after stirring, 10 mL of CMC solution (pH 6.0) was slowly added dropwise. Stirring was continued for 30 min to form a positive and negative charge composite system. Finally, WPI solution was added, and the pH was adjusted to 3.8 with 1 mol / L HCl to obtain ACNs-CHC / CMC-WPI nanocomposite (CHC / CMC mixed solution: WPI solution = 1.5:1).
[0043] (3) Thin films loaded with ACNs-CHC / CMC-WPI nanocomposites
[0044] 1.5 g of chitosan (CS) was dissolved in 0.5% acetic acid solution (40 °C). 2 g of corn starch (CT) was gelatinized in a 95 °C water bath and then cooled to 50 °C, and mixed with the CS solution. 30 wt% glycerol was added as a plasticizer. After ultrasonic treatment (240 W, 28 kHz, 15 min), a nanocomposite solution was added according to a volume ratio of 5:3 between the mixed solution loaded with anthocyanin complex and the ultrasonic mixed film solution. The mixture was poured into a mold and dried (25 °C, 40% RH, 1.5 h). This film is designated as CTS / Corn-AN film.
Claims
1. A highly antioxidant, color-changing, intelligent active preservation film containing bilberry anthocyanins. Compared with traditional chitosan / corn starch films (CTS / Corn-FA) without encapsulated bilberry anthocyanins, a film (CTS / Corn-AN film) is prepared by adding a nanocomposite (ACNs-CHC / CMC-WPI) containing bilberry anthocyanins encapsulated in chitosan hydrochloride (CHC), sodium carboxymethyl starch (CMC), and whey protein isolate (WPI) to a chitosan / corn starch mixed matrix. This film exhibits significantly enhanced mechanical strength and barrier properties, and displays reversible color changes within a pH range of 2-13. Under 28 days of light exposure, its antioxidant activity retention rate is significantly improved compared to traditional films, while maintaining the original color of shrimp. It significantly inhibits weight loss, pH increase, and TBARS accumulation during shrimp storage, demonstrating superior preservation capabilities for high-protein aquatic products.
2. A method for preparing a highly antioxidant, color-changing, intelligent active food preservation film containing bilberry anthocyanins, comprising the following steps: (1) Preparation of nanocomposites containing bilberry anthocyanins: (1.1) Fresh blueberries were crushed, and after ultrasonic extraction, purification and freeze-drying, blueberry anthocyanin extract powder was obtained. (1.2) Dissolve bilberry anthocyanin extract powder, chitosan hydrochloride (CHC), sodium carboxymethyl starch (CMS) and whey protein isolate (WPI) in pure water respectively. Add CMC solution to bilberry anthocyanin extract solution; then slowly add CMC solution and stir; then add WPI solution to obtain a nanocomposite solution containing bilberry anthocyanin. (2) Preparation of a highly antioxidant, color-changing, intelligent, active food preservation film: (2.1) Dissolve chitosan in acetic acid solution; dissolve corn starch in distilled water and gelatinize; (2.2) Mix chitosan solution with starch paste, add glycerin, sonicate, cast into a film and dry to obtain the final product.
3. The method according to claim 2, characterized in that: In step (1.2), the ratio of CHC / CMC mixed solution to WPI solution in the nanocomposite solution containing bilberry anthocyanin is 2:1 (pH=3.8).
4. The method according to claim 2, characterized in that: In step (2.2), the ratio of chitosan (CS) to corn starch (CT) is 3:
4. After ultrasonic treatment, the loaded anthocyanin nanocomplex solution is mixed with the ultrasonic mixed membrane solution at a volume ratio of 5:3, poured into a circular plastic mold with a diameter of 8 cm, and left to stand until the air bubbles completely disappear. After drying, a thin film is formed.
5. A highly antioxidant, color-changing, intelligent active food preservation film containing bilberry anthocyanins, characterized in that: Prepared using the method of any one of claims 2-4.