Evaluation of polar compound distribution in edible oils under restaurant deep frying

The distribution of polar compounds (PCs) in palm oil (PO), rapeseed oil (RO), and high-oleic sunflower oil (HOSO) were monitored in French fries (FF), chicken nuggets (CN), and fish nuggets (FN) real restaurant deep-frying systems by high-performance size exclusion chromatography. The PO with long frying life (100–186 h) showed better oxidation stability in all frying systems compared with RO and HOSO. All the oils had a close increasing trend in triacylglycerol hydrolysis products (THP), while RO and HOSO had higher levels of oxidized triacylglycerol monomers (OTG) and oxidized triacylglycerol polymers (TGP) than PO during frying. During FF frying, the oils deteriorated slowest from the aspect of PCs rising to the discard point (27 %). The oils underwent more serious hydrolysis and polymerization while CN and FN were fried compared to FF frying. However, OTG contents in oils altered irregularly and there was no obvious disparity among different foods frying. Oil type, fried food, and even the interaction between them significantly (p < 0.001) affected polar compound distribution.