This study aimed to investigate the quality characteristics and flavor compounds of caged and cage-free chicken eggs. Fresh unfertilized caged and cage-free Xianju chicken eggs were used for quality parameter and flavoromics analyses. Cage-free eggs had higher yolk weight and yolk ratio, whereas caged eggs had higher malondialdehyde level and Haugh units. There was no significant difference in amino acid composition between the caged and cage-free eggs. Flavoromics analysis revealed that cage-free eggs exhibited higher levels of alcohols, acids, and ketones, exhibiting more pronounced fruity and floral notes. In contrast, the caged eggs had higher levels of aromatic compounds, exhibiting a mild flavor. Furthermore, the integration of flavoromics with relative odor activity value analysis indicates that 1-Octen-3-ol, ( R , R )-2,3-Butanediol, Dimethylthiomethane, (E)-2-Octenal, (E)-2-Decenal, and acetoin were potential indicators for differentiating between caged and cage-free eggs. This study provides important data to support the optimization of egg production systems and quality improvements. • Cage-free eggs have higher yolk weight and ratio; caged eggs have higher Haugh units. • Untargeted flavoromics reveals distinct volatile profiles between caged and cage-free eggs. • Cage-free eggs are richer in alcohols/ketones, contributing fruity and floral notes. • Caged eggs contain more aromatic compounds, resulting in a milder flavor profile. • Six volatile compounds (e.g., 1-Octen-3-ol) are identified as potential biomarkers for distinction.
Zeng et al. (Wed,) studied this question.