Incorporation of salmon bone gelatine with chitosan, gallic acid and clove oil as edible coating for the cold storage of fresh salmon fillet

Abstract

Edible coating is an effective strategy to improve the product quality and extend the shelf life of meat products. The objective of this research was to extract gelatine from salmon fish bone and develop a salmon bone gelatine-chitosan based edible coating incorporating gallic acid and/or clove oil as bioactive ingredients for the preservation of fresh salmon fillet at cold storage (4 °C for 15 days). The extraction yield of salmon bone gelatine was 2.5 ± 0.5% wet basis. The salmon bone gelatine extract coating (GE) successfully inhibited discolouration, pH change, lipid and protein oxidation and microbial growth of salmon fillet, but was less effective compared to chitosan coating (CH). The combination of gelatine and chitosan (GE-CH) and the incorporation of gallic acid (GE–CH–GA) improved the antioxidant effects of the coating. In contrast, incorporation of clove oil (GE–CH–CO) enhanced the antimicrobial effects. Overall, the combination of gelatine, chitosan, gallic acid and clove oil (GE–CH–GA-CO) had the best performance on salmon fillet preservation and prolonged the shelf life for at least 5 days. These findings suggest the potential to develop this mixture (GE–CH–GA-CO) as a practical commercial method for the preservation of fresh fish meat.