Fabrication of chitosan composite films reinforced with fish scale gelatin-hydroxyapatite and syringaldehyde for beef preservation.

Abstract

Fish scale waste was valorized to develop a biodegradable active film with enhanced preservation performance. Gelatin and hydroxyapatite were extracted and combined with chitosan, while syringaldehyde was incorporated as a natural crosslinker and antibacterial agent to construct a dual-network structure. The combination of HAP reinforcement and SA-induced crosslinking promoted the formation of a denser organic-inorganic network structure, thereby improving the physical performance and functional properties of the films. Compared with the blank GC film, the incorporation of HAP and SA led to the formation of GCHS films with overall enhanced physical performance and functionality. Especially, the optimized GCHS3 film exhibited improved elongation at break (51.7%), UV-blocking ability (blocking >99% of UV passage), DPPH radical scavenging activity (82.3%), and antibacterial effects against Escherichia coli and Staphylococcus aureus (with inhibition zone diameters of 14.09 mm and 24.00 mm, respectively). During cold storage of beef samples, the GCHS3 film efficiently inhibited microbial growth, delayed the accumulation of total volatile basic nitrogen, and retarded pH increase, while maintaining the original color characteristics of beef. Consequently, the shelf life was extended to 9 days, which is superior to PE packaging. This study provides a novel strategy to incorporate fish scale-derived inorganic fillers and natural crosslinkers into protein-polysaccharide systems. The GCHS3 film exhibits great potential as a sustainable alternative for active food packaging, especially for fresh meat preservation.