Title: Stability and quality of fish oil during typical domestic application

The objective of this project was to investigate the oxidation degree of fish oil and to improve its stability by addition of tocopherol during simulated domestic application. Fresh oil obtained from fish species containing high amounts of n-3 poly unsaturated fatty acids (EPA, 18.2%; DHA, 12.2%) was used for the study. Typical domestic application was simulated by storing the fish oil at 10°C and taking daily portions of fish oil while exposed to room temperature for 30 min. The stability and quality of fish oil were evaluated by measuring the peroxide value and the anisidine value. Minor changes were observed in the peroxide values of the fish oil during the initial 30 days, but for safe consumption of fish oil without antioxidant, a maximum of 36 days shelf life is suggested under storage conditions for domestic consumption. Addition of 0.01% tocopherol had no significance for retarding autoxidation of the fish oil and the anti-oxidative effect of tocopherol did not increase with concentrations of tocopherol higher than 0.05%. In case of fish oil with tocopherol 0.05%, the acceptable limit (PV = 8meq/kg) in peroxide value for human consumption was reached in 41 days, corresponding to a 14% improvement in stability, in comparison with fish oil without tocopherol. The longest storage time to PV = 8 meq/kg was found in the sample with Ronaxan 0.05% at 44 days, which means about a 22% improvement in oxidative stability of the fish oil. There was very little secondary oxidation of the fish oil and no significant effects of antioxidants on changes in anisidine values throughout the storage time.