Effect of neutralization treatment on properties of chitosan/bamboo leaf flavonoids/nano-metal oxide composite films and application of films in antioxidation of rapeseed oil

• Published in: International journal of biological macromolecules 2023-07, Vol.242 (Pt 3), p.124951-124951, Article 124951
• Main Authors: Liu, Yi-Qi, Song, Qiao-Wei, Mo, Chun-Ru, Yu, Wen-Wen, Hu, Chang-Ying
• Format: Article
• Language: English
• Subjects: Bamboo leaf flavonoid; Chitosan film; Neutralization
• ISSN: 0141-8130; 1879-0003
• DOI: 10.1016/j.ijbiomac.2023.124951

Neutralization treatment improved the slow-release antioxidant food packaging function of chitosan (CS)/bamboo leaf flavone (BLF)/nano-metal oxides composite films. The film cast from the CS composite solution neutralized by KOH solution had good thermal stability. The elongation at break of the neutralized CS/BLF film was increased by about 5 times, which provided the possibility for its packaging application. After 24 h of soaking in different pH solutions, the unneutralized films swelled severely and even dissolved, while the neutralized films maintained the basic structure with a small degree of swelling, and the release trend of BLF conformed to the logistic function (R2 ≥ 0.9186). The films had a good ability to resist free radicals, which was related to the release amount of BLF and the pH of the solution. The antimicrobial neutralized CS/BLF/nano-ZnO film, like the nano-CuO and Fe3O4 films, were effective in inhibiting the increase in peroxide value and 2-thiobarbituric acid induced by thermal oxygen oxidation of rapeseed oil and had no toxicity to normal human gastric epithelial cells. Therefore, the neutralized CS/BLF/nano-ZnO film is likely to become an active food packaging material for oil-packed food, which can prolong the shelf life of packaged food.