Development and characterization of composite films based on chitosan and collagenous proteins from bluefin tuna: application for peeled shrimp preservation

In the current study, composite films based on blue crab chitosan (Cs) and bluefin tuna collagenous proteins (BTCP) were prepared and characterized. Composite films were assessed for their physicochemical, barrier (water vapor and UV), structural, crystallinity, thermal, mechanical and antioxidant properties. FTIR analysis showed an increase of hydrogen bonding formation between polymers with the increase of BTCP content. Additionally, the addition of BTCP to the Cs solution at a volume ratio of 10:90, consequently forming the Cs90-10BTCP film, improved the water vapor permeability and UV barrier capability of the composite films compared to the chitosan film. Interestingly, the incorporation of BTCP improved significantly the antioxidant activity of composite films, allowing them to be successively used as bioactive packaging materials. The ability of Cs-BTCP film solutions as a coating for shrimp preservation was also investigated. The Cs90-10BTCP film solution showed better preservative effect on shrimps in terms of preventing the lipid peroxidation and delaying the growth of spoilage microorganisms. Hence, these findings suggested that the Cs-BTCP coating preserved the shrimps throughout the refrigerated storage period.