Lipid-derived odour-active volatile compound formation pathways in Tibetan pork across different cooking methods: Insights from iron properties, lipid oxidation, and lipidomics analysis

Abstract

Tibetan pork is a local Chinese pig breed that is raised in high-altitude environments. This study examined the formation pathways of lipid-derived odour-active volatile compounds in Tibetan pork across three cooking methods: sous-vide (SV), pan-frying (PF), and oven-roasting (OR), by investigating the pro-oxidative roles of free iron and changes of lipid molecules. It was found that lipid-derived volatiles in low-temperature methods were generated in two stages: initially from free fatty acids and lysophosphatidylcholines, and later from the oxidation of phospholipids, with the later stage being affected by free iron, which followed by increasing lipid oxidation properties. Conversely, high-temperature methods such as PF and OR led to rapid lipid oxidation at the beginning of cooking, producing odours from eicosanoids, triglycerides, and phospholipids, while their oxidation was less impacted by free iron. The lipid-derived compounds were probably the intermediate products in the development of Strecker- and Maillard-derived volatiles during high-temperature cooking.

Keywords: Free iron; Lipid molecules; Phospholipids; Pork flavour; Thermal treatment.