Abstract: To explore the quality characteristics of Gaoyou duck eggs, metabolomics was used to analyze the quality indexes, basic nutritional indexes and small molecule metabolites. The results showed that the mass, egg shape index, egg yolk color, Haugh unit, egg white height, egg yolk index and crude protein content of Gaoyou duck eggs were higher than those of the other studied breeds. The contents of total amino acids, umami amino acids, branched-chain amino acids, total fatty acids and unsaturated fatty acids were higher, and the content of saturated fatty acids was lower, indicating that sensory quality parameters, amino acids and fatty acids can characterize the quality of Gaoyou duck eggs. The characteristic components of Gaoyou duck eggs were uncovered by metabolomic fingerprinting, principal component analysis (PCA), partial least squares discriminant analysis (PLS-DA), and hierarchical cluster analysis (HCA). Totally 252 compounds and 22 differential compounds were identified in egg yolk, and 184 compounds and 40 differential compounds in egg white. Among them, uridine 5’-monophosphate, guanosine 5’-monophosphate, and N-acetyl-D-glucosamine were the main differential nutrients, and arachidonic acid in egg yolk was the unique nutrient of Gaoyou duck eggs, while indole was not detected in the egg white of Gaoyou duck eggs.

Key words: Gaoyou duck eggs; conventional egg quality indicators; basic nutritional indicators; metabolomics