Comparison of the Metabolic and Flavor Characteristics of the Egg Yolks of BIAN Chicken and Hy-Line Brown Chicken Using LC-MS and GC × GC-TOF MS Techniques.

This study systematically compared the differences in egg quality between the BIAN chicken, an indigenous breed of Shanxi Province, and the Hy-Line Brown, a commercial breed, through the integration of non-targeted metabolomics and volatile flavoromics methods. A total of 675 metabolites and 84 volatile flavor compounds were identified in eggs from 300-day-old laying hens using LC-MS and GC × GC-TOF MS techniques. BIAN chicken eggs exhibited notable advantages in flavor quality. The relative odor activity value (ROAV) of 1-octen-3-ol, a key flavor component, was 27.01 in BIAN compared with 13.46 in Hy-Line Brown, contributing to the characteristic mushroom aroma of BIAN eggs. Furthermore, the levels of heptaldehyde, 2-pentylfuran, and styrene in BIAN chicken eggs were significantly elevated, contributing to its characteristic flavor profile. Metabolomic analysis identified 40 breed-specific metabolites in BIAN chicken, with 21 up-regulated and 19 down-regulated. These metabolites were primarily involved in biological processes such as α-linolenic acid metabolism, cholesterol metabolism, and unsaturated fatty acid biosynthesis, highlighting the distinctive lipid metabolism regulation in BIAN chicken. Sensory evaluation based on relative odor activity values (ROAV) demonstrated that BIAN chicken eggs exhibited enhanced sweet, fruity, herbal, and citrus aromas, which correlated with the enriched lipid metabolism pathways. This study elucidates the molecular basis of distinctive egg quality characteristics in local chicken breeds, offering a scientific rationale for the conservation and utilization of indigenous breeds and the documentation of their unique metabolic and sensory properties. Furthermore, it furnishes a theoretical framework for understanding breed-specific flavor development and provides baseline data for future genetic selection and nutritional intervention strategies.