Effect of chitosan coating enriched with rice-bran extract on the shelf-life of rainbow trout (Oncorhynchus mykiss) during cold storage

The present study was conducted to evaluate the effect of antimicrobial and antioxidant chitosan coating enriched with rice-bran extract on the shelf-life extension of trout fillet. Rice-bran extract was extracted with 80% methanol. Samples were separated into three groups; uncoated and without rice-bran extract (Control), coated with chitosan and coated with chitosan containing 2% rice-bran extract. Fish fillets were stored at refrigerated condition (4±1˚C) for 20 days. Lipid contents, chemical characteristics (peroxide value, thiobarbituric acid, free fatty acids, pH) and microbial (total bacteria and psychrophilic counts) and organoleptic properties (odor, color, texture, and general acceptability) were compared in fillets at various days of cold storage (0, 4, 8, 12, 16 and 20 days). Chitosan coating and chitosan coating containing rice-bran extract had positive effect in reducing the peroxide value, thiobarbituric acid, free fatty acids and pH. Microbial analysis indicated that coating enriched with rice-bran extract had a significant effect in the reducing the total bacteria and psychrophilic counts. Results showed that chitosan coatingand using rice-bran extract in coating had significant effects in reducing the chemical indices of spoilage and microbial properties and extension the shelf-life of trout fillets