Changes in lipid profiles and volatile compounds of shrimp (Penaeus vannamei) submitted to different cooking methods

Herein, the effect of three common cooking methods (boiling, baking and microwaving) on lipids and volatile compounds in shrimp (Penaeus vannamei) was assessed. The results revealed that contents of phospholipid, triglyceride, cholesterol and free fatty acids in the cooked shrimp significantly declined when compared to the raw shrimp. And these decreases occurred especially in the boiling and microwaving treatment. Among free fatty acids, the contents of palmitic acid (C_16:0), oleic acid (C_18:1n9c) and linoleic acid (C_18:2n6c) also decreased greatly in the boiled and microwaved shrimp, while EPA and DHA enhanced in each cooked group (P < 0.05). Furthermore, microwaved samples exhibited higher levels of oxidation parameters, such as acid value (AV) and thiobarbituric acid-reactive substances (TBARS). For volatile compounds, a total of 31 volatile compounds were detected by GC-IMS, and these contents increased after cooking. Aliphatic volatile compounds, including 1-octen-3-one, pentane-1-ol, 1-propanol, octanal, heptanal, pentanal and hexanal, were main flavour contributors in cooked shrimp, with higher contents observed in microwaved shrimp. In addition, the correlation analysis showed that linoleic acid was a substrate for 15 volatile compounds of cooked shrimp meat. These results indicate that microwave cooking exerts more influences on lipid profiles in shrimp and consequently caused more volatile compounds.