Lipid Oxidation Is Inhibited by Isoeugenol Exposure in Chinook Salmon (Oncorhynchus Tshawytscha) Fillets during Storage at 15 °C

The method of harvest for farmed fish and the postharvest tissue metabolism can have a significant effect on the quality and storage stability of the resulting fillets. We have examined the effects of rested harvesting and I isoeugenol exposure on tissue oxidation and the loss of tissue antioxidants in fillets of chinook salmon (Oncorhyncus tshawytscha) during storage at a normal metabolic temperature of 15 degrees C. Isoeugenol is a lipid soluble phenolic antioxidant used as an anesthetic in the aquaculture industry (AQUI-S (TM)). Fillets from salmon harvested in rested and exhausted physiological states with and without isoeugenol were prepared and stored in air at 15 degrees C for 96 h. Exposure to isoeugenol resulted In significantly decreased late-stage lipid peroxidation (TBARS) levels in the fillets during storage regardless of the harvest method. Protein carbonyl concentrations increased 73% in the fillets during storage (from 406 to 703 nmol/g wet weight) and were not affected by the harvest method. Fillet vitamin C concentrations decreased 92% (from 49 to 4 nmol/g wet weight) but were also not affected by the harvest method. Although significant late-stage lipid oxidation was observed with exhausted harvesting, no significant vitamin E loss was observed in any of the fillets during storage. Our results show that rested harvesting of chinook salmon does not affect their oxidative stability immediately postharvest and that isoeugenol can function as an antioxidant in fish fillets as it prevented late-stage lipid oxidation.