Effect of edible coating based on salep containing orange ( Citrus sinensis ) peel essential oil on shelf life of rainbow trout ( Oncorhynchus mykiss ) fillets

Abstract

Fish are highly perishable foods due to their high body water and neutral pH and spoil faster than other meat foods. In this study, the effect of coating of salep gum containing concentrations of zero, 0.25% and 0.5% of orange peel essential oil in preventing the growth of microbial flora and chemical spoilage and increasing the shelf life of fish fillets in the refrigerator during 16 days of storage was investigated. The results showed that during storage, the number of total aerobic mesophilic, psychrophilic, coliforms and lactic acid bacteria, pH, total volatile base nitrogen, peroxide value, and thiobarbituric acid increased significantly in all treatments, that was less in treatments coated by salep containing orange peel essential oil (p < .01). Based on our findings, the shelf life of fillets can be increased to at least 12 days by coating them with the salep containing 0.5% orange peel essential oil. Practical applications In the last decade, the consumption of fish is increasing due to its health benefits. However, fish are highly susceptible to microbial contamination. The use of edible coatings with antimicrobial and antioxidant compounds is an effective way to maintain the quality of fish. Based on our findings, the shelf life of fillets can be increased to at least 8 and 12 days by coating them with the salep containing 0.25% and 0.5% orange peel essential oil, respectively.