Characterization of fish collagen from blue shark skin and its application for chitosan- collagen composite coating to preserve red porgy (Pagrus major) meat.

Pepsin soluble collagen (PSC) was extracted from blue shark (Prionace glauca) skin and was used for chitosan-collagen composite coating to investigate coating effects on fresh red porgy (Pagrus major) fillet quality during storage at 4°C. Total volatile basic nitrogen (TVB-N), thiobarbituric acid (TBA), pH, K value, drip loss, and sensory evaluation scores were measured as deterioration indexes. Results show that coating by 1% of chitosan solutions containing 0.0%-0.8% of PSC significantly improved most deterioration indexes. Coating by 1% of chitosan solution containing 0.8% of PSC yielded the best results for K value, drip loss, and sensory evaluation, although the other indexes show no clear PSC concentration dependence. These results indicate 1% of chitosan solution containing 0.8% of PSC as the best coating formulation examined in this study. PRACTICAL APPLICATIONS: Aquatic products have high contents of water and protein. Their qualities are likely to decline because of endogenous chemical and enzyme reactions, and also because of the role of spoilage and pathogenic microorganisms during storage. The edible collagen and chitosan coating suggested by this research is biodegradable, biocompatible, cost effective, and is able to meet the requirements for food quality and storage duration. Pepsin soluble collagen (PSC) is an aquatic product processing by-product that makes the maximum use of resources. As described herein, a composite formulation comprising collagen and chitosan improves preservation effects of different types of coatings. A more high-quality and effective edible coating formulation was obtained, thereby extending the red porgy fillet shelf life. © (2020) Wiley Periodicals LLC.