Tracking of Maillard-modified phospholipids in thermally processed edible insects by orthogonal LC-MS approaches

The increasing use of edible insects as sustainable food ingredients calls for a deeper understanding of chemical changes induced by thermal processing. While the Maillard reaction (MR) is well known to affect proteins, its impact on aminophospholipids remains poorly explored, particularly in insect-based foods. In this study, an analytical workflow combining hydrophilic interaction liquid chromatography and C30 reversed-phase LC coupled to high-resolution tandem mass spectrometry, operated in dual ESI polarity, was developed to characterise MR-derived phosphatidylethanolamines (PEs) in processed crickets (Acheta domesticus). The approach enabled structural elucidation of both diacyl and ether-linked modified PEs. Four classes of known modified species, i.e. formyl-, acetyl-, N-glycosyl-, and N-diglycosyl-PEs were consistently detected. Moreover, hydroxymethylfurfural-PEs and gluconoyl-PEs were identified for the first time. Class-specific diagnostic fragments and mass shifts allowed unambiguous annotation. These findings reveal an unexpected diversity of heat-induced lipid modifications and highlight their potential as candidate markers of thermal processing.