Longan seed enzymatic hydrolyzate-carboxymethyl chitosan blended films: Interaction mechanism and multifunctionality.

Abstract

Carboxymethyl chitosan (CMCS) films exhibit limited functionality, a constraint that impedes their large-scale application in food packaging. The objective of this study was to modify CMCS films with longan seed extracts (LSE) to enhance their comprehensive performance. The fundamental physicochemical properties of LSE were characterized, and the structure-performance relationship of the resultant blended films was explored. All samples were characterized for microstructure, mechanical properties, water vapor permeability, UV-blocking ability, and antibacterial activity. The findings indicated that incorporating LSE imparted the films with a tensile strength of 24.91 ± 3.80 MPa and an elongation at break of 35.59 ± 4.27%. The water vapor permeability of the samples decreased, ranging from 29.57% to 51.25%, and the ultraviolet shielding efficiency was enhanced by 4.31-4.82 times. The incorporation of LSE effectively addressed the functional limitations of neat CMCS films. This work presents a viable strategy for fabricating high-performance active packaging films using extracts from agricultural by-products.