The mechanism of egg yolk lecithin in improving the quality of chili oil during thermal processing: Integrated insights from lipid oxidation and flavoromics.

Egg yolk lecithin was evaluated as a natural additive to improve chili oil during thermal processing. Lecithin (0-3.6%, w/w) significantly enhanced oxidative stability and reshaped the volatile profile. At 2.0% lecithin, acid value and TBARS decreased from 0.03344 to 0.00792 mg/g and from 0.022 to 0.012 mg/kg, respectively, while DPPH radical scavenging activity at 10 mg/mL rose from 63.77% to 86.48%. Although 3.6% lecithin exhibited the strongest antioxidant effect, 2.0% gave the highest sensory acceptability. GC-IMS and HS-SPME-GC-MS identified 38 and 83 volatiles, respectively. Lecithin reduced d-limonene and linalool but increased 5-hydroxymethylfurfural, furfuryl alcohol and 2-pentylfuran. Eight differential metabolites (VIP > 1, p < 0.05) were identified, among which acetaldehyde, linalool, nonanal, (E)-2-heptenal and 2-pentylfuran had OAV > 1. Overall, 2.0% lecithin offered the best balance of oxidative stability, sensory quality and aroma optimization.