Abstract: The relationship between the formation of volatile compounds and changes in the fatty acid composition of female Chinese mitten crab (Eriocheir sinensis) during cooking was investigated. The volatile compounds were detected by head-space solid phase microextraction and gas chromatography-mass spectrometry (GC-MS). The total lipids (TLs) were separated by solid phase extraction for GC analysis of the fatty acid composition of polar (PLs) and neutral (NLs) lipids. Removal of total lipids had a marked effect on the profile of volatile compounds, especially aldehydes (hexanal, heptanal, (E)-2-octenal, (E,Z)-2,6-nonadienal, (Z)-2-decenal, undecanal, and pentadecanal) and ketone (2-nonanone). An increase in the NLs and a decrease in the PLs were observed during cooking, while the TLs did not change significantly. Further analysis showed reduced contents of saturated fatty acids (SFA), monounsaturated fatty acids (MUFA) and polyunsaturated fatty acids (PUFA) in the PLs during cooking. Furthermore, unsaturated fatty acids of the PLs, especially C18:1n-9c, C20:1n-9, C20:4n-6 and C22:6n-3, showed the same decreasing trend as those of the TLs. The findings demonstrated that the fatty acids in the PLs might be the flavor precursors of the aldehydes and ketone derived from lipid thermo-oxidation and degradation during cooking.

Key words: Eriocheir sinensis, volatile compounds, lipid fractionation, solid-phase extraction (SPE), fatty acid