Effect of frying on the lipid oxidation and volatile substances in grass carp ( <i>Ctenopharyngodon idellus</i> ) fillet
Xiangfei Hu, Jinlin Li, Lu Zhang, Hui Wang, Bin Peng, Yueming Hu, Qingxi Liang, Zongcai Tu
Abstract
The effects of pan-frying temperatures (160 and 200°C) and time (2, 4, 6, and 8 min) on fatty acid oxidation and volatile substances of grass carp fillets were investigated. Compared with raw samples, the content of monounsaturated fatty acids in the treated samples was significantly reduced (p < .05), and the polyunsaturated fatty acids were endowed with higher oxidation stability. Both peroxide values and the content of free amino acids were significantly increased in the first 4 min and subsequently decreased, while carbonyl values increased within 8 min (p < .05). In addition, the flavor profile showed a significant diversity, mainly due to the conversion of lipid derivatives to pyrazine and furan. Multivariate data analysis demonstrated that a total of 18 volatile substances were identified as the principal contributing substances. Conclusively, the oxidation of unsaturated fatty acids was an essential channel responsible for flavor substances. Practical applications The study could provide a deep observation on a pattern of flavor formation and lipid oxidation on fried grass carp fillets. The primary flavor compounds of fried grass carp fillets were identified. This research can provide theoretical guidance for scientific aquatic product processing to improve nutrition, reduce harmful substances, and regulate the formation of processing flavors.