Lipidomics and GC-MS analyses of key lipids for volatile compound formation in crayfish meat under different thermal processing treatments

The changes of lipids and volatile compounds in crayfish meat under different thermal processing treatments including boiling (BO), air frying (AF), and BO-AF were analyzed by UPLC-Q-TOF-MS/MS and gas chromatography-mass spectrometry (GC-MS). The results found that a total of 596 lipids were identified from the crayfish meat. Among them, lysophosphatidylcholine (LPC) 18:1 and lysophosphatidylethanolamine (LPE) 18:1 may be the major aroma retainer for air-fried crayfish meat, while triacylglycerol (TG) 16:0_18:1_18:2 for boiled crayfish meat. Statistical analysis showed that a total of 78 lipid molecules contributed significantly to crayfish meat, of which LPE20:5, LPE22:6, LPE18:3, LPE18:0, LPE18:1, and LPE18:2 may be potential markers that distinguish air-fried crayfish meat from other thermally processed one. In addition, 14 volatile compounds were identified as characteristic aroma compounds of crayfish meat, with aldehydes and heterocyclic compounds contributing significantly to air-fried crayfish meat. LPE and diacylglycerol (DG) as key substrates for flavor compound formation during thermal processing of crayfish meat.