A novel LA@Cu-MOF film with dual response to pH and humidity: Preparation, antibacterial activity, and fruit preservation

Abstract

At present, fruits still undergo extensive decay and deterioration after harvesting. α-Lipoic acid (α-LA) is a natural, pollution-free, and low-cost preservative, which can effectively inhibit the senescence of postharvest fruits. To better utilize the preservation potential of α-LA, in this study, it was reacted with Cu-metal-organic framework (Cu-MOF) and loaded in large quantities onto the Cu-MOF, known as LA@Cu-MOF. On this basis, an antibacterial film with dual responsive release was prepared. The results indicated that LA@Cu-MOF exhibited a significant inhibitory effect on S. aureus, E. coli, and B. cinerea. Additionally, the release of α-LA in the film demonstrated superior response release in weakly acidic and high humidity environments. Moreover, the coating film could maintain the appearance and quality indicators of fruits for at least 6 days. Therefore, this method effectively extended the shelf life of fruits while maintaining their quality, making it a promising intelligent responsive fruits preservation material.