Comparative analysis of quality characteristics and lipid profiles in Linwu and Shaoxing duck egg yolks based on untargeted lipidomics

• The appearance of Linwu and Shaoxing duck eggs are markedly different. • Untargeted lipidomics comparison of yolks from Linwu and Shaoxing duck eggs reveals distinct lipid profiles. • Linwu egg yolks had higher triglycerides and phosphatidylcholine levels, whereas Shaoxing egg yolks exhibit higher phosphatidylethanolamine level. • The differential lipids between Linwu and Shaoxing duck egg yolks were mainly enriched in membrane components and lipid-mediated signaling functions. • Integrated of lipidomics with co-occurrence network analysis identifies novel lipid biomarkers for Linwu and Shaoxing duck egg yolks distinction. This study aimed to explore the quality characteristics and lipid profiles of egg yolks from Linwu and Shaoxing ducks using untargeted lipidomics based on UPLC-MS/MS. No significant difference in shell strength and Haugh unit between Linwu and Shaoxing duck eggs. The appearance of Linwu and Shaoxing duck eggs are markedly different, Linwu duck egg yolks exhibited higher total cholesterol and polyunsaturated fatty acids levels. Shaoxing duck egg yolks had higher water content and monounsaturated fatty acids levels. Lipidomics analysis revealed that triglyceride (TG) and phosphatidylcholine (PC) were the most abundant lipids, followed by phosphatidylethanolamine (PE) and ceramides in Linwu and Shaoxing duck egg yolks. Linwu duck egg yolks had higher TG and PC levels, whereas Shaoxing duck egg yolks had higher PE level. The differential lipids between the Linwu and Shaoxing duck egg yolks exhibited higher carbon chain lengths and were mainly enriched in membrane components, lipid-mediated signaling, and transition functions. Furthermore, integrating of lipidomics with co-occurrence network analysis indicates that TG (19:1_18:1_20:3), PC (16:0_22:6), and PE (18:0e_18:1, 18:1e_20:1, and 18:1e_22:3) were potential indicators for differentiating Linwu and Shaoxing duck egg yolks. This study provides an important data support for improving quality and nutrition of egg products.