Rancidity development of refrigerated rainbow trout (Oncorhynchus mykiss) fillets: comparative effects of in vivo and in vitro lycopene

BACKGROUNDThe problem of lipid oxidation in fish during storage is well known and is related to both temperature and storage time. Antioxidants could have a main role in limiting the deteriorative effects of lipid oxidation in fish. The present study aimed to investigate the effect of dietary supplement against postmortem addition of lycopene on the deterioration of trout fillets during storage at 41 degrees C for 12days. RESULTSAt the end of the feeding trial, no significant differences were observed with respect to the fatty acid composition of different dietary groups. However, a strong positive correlation (r = 0.96) was observed between fillet and diet lycopene levels. Lower indices of lipid oxidation (peroxide value and thiobarbituric acid) and lipid hydrolysis (free fatty acids) were observed in fillets that received lycopene (P<0.05). Although exogenous lycopene was more effective (P<0.05) than endogenous lycopene in delaying lipid oxidation, the fatty acid composition of fillets that received dietary lycopene supplement showed a higher stability (P<0.05) during refrigeration storage. CONCLUSIONAccordingly, based on the time of appearance of off-odors and discoloration in fish fillets, exogenous lycopene, especially at higher levels, was more effective in terms of quality parameters. (c) 2017 Society of Chemical Industry