Effect of chitosan Enriched with a- Tocopherol Coating on Trout Quality and Shelf life during Refrigerated Storage

Fresh fishes compared to red meats and chicken are more susceptible to spoilage however, damages lead to decrease in fish nutritional values. The object of this study was to enrich chitosan coating with a-tocopherol to prepare coating with both antimicrobial and antioxidant characteristics to improve quality and shelf life of fish as a dietary source. Chitosan solution (2%) and chitosan enriched with α-tocopherol in two concentrations (0.2% and 0.4%) were prepared for coating of the trout samples and they stored at 4±1°C. The control and the coated fish samples were analyzed periodically (at 7 day intervals) to determine peroxide value and thiobarbituric acid value, weight loss, pH, microbial analysis (total viable counts, psychotropic counts) and sensorial attributes (colour, odour, texture). As compared with the control samples, fewer changes were observed in oxidative indices, microbial counts, weight loss, pH, sensory evaluation in the samples treated with coating during refrigerated storage. In chitosan enriched a tocopherol treated samples, peroxide and thiobarbituric acid values were significantly less than other samples (p lt;0.05). Minimum oxidation rate belonged to chitosan coating enriched with 0.4% a tocopherol.