Effect of Frying on Fatty Acid Profile, Free Amino Acids and Volatile Compounds of Grass Carp (Ctenopharyngodon idellus ) Fillets

The effect of frying on fatty acid profile, free amino acids and volatile compounds of grass carp (Ctenopharyngodon idellus) fillets was investigated by comparing two frying time points (2 and 4 min). Although frying decreased overall fatty acid content with different degree of degradation between the two frying time points, the content of C18:2 n-6 and C18:3 n-3 was significantly increased (P < 0.05). By contrast, the total free amino acids content increased from 53.36 nmol/kg in raw to 65.03 and 72.18 nmol/kg in samples fried for 2 and 4 min, respectively. It appeared that frying likely increased the content and number of volatiles since 13 and 4 novel volatiles were formed during 0–2 and 2–4 min of frying, respectively. It can be concluded that frying improves the taste and flavor of food, but decreases the nutritional value of grass carp fillets to some extent. Practical Applications Grass carp (Ctenopharyngodon idellus), one of the most important freshwater fish, is a valuable source of nutrition. It is usually treated by one or more various cooking processes before consumption, which gives rise to major changes in composition. Frying is one of the most common methods for processing fish to improve its nutrition, flavor and taste. The purpose of this study was to investigate the effect of frying on fatty acid composition, free amino acids and volatiles in grass carp meat. The results of this study provide a better understanding of how frying influences the nutrition and taste of grass carp fillets, and how the overall volatile profile changes during frying. This information could provide scientific guidance for processing delicious, nutritional and healthy fish products, and promote the application of grass carp even freshwater fish in food industry.