Abstract: This study employed gas chromatography-olfactometry coupled with high-resolution mass spectrometry (GC-O-HRMS) to analyze volatile odor compounds in four common types of commercial poultry eggs, aiming to clarify the primary sources of egg flavor and reveal the flavor characteristics of eggs from different species of poultry. After cooking, volatile compounds from the egg samples were enriched using headspace solid-phase microextraction (HS-SPME) and detected by gas chromatography-orbitrap mass spectrometry, and their odor characteristics were analyzed using an olfactometer. By matching mass spectra and retention indices against the NIST library and a self-built mass spectral library, volatile aldehydes, hydrocarbons, and sulfur- or nitrogen-containing compounds were identified in both egg yolk and white, while the number of these compounds was significantly higher in egg yolk than in egg white. Quail egg yolk exhibited the greatest variety of volatile compounds (61) and the highest relative content of sulfur- or nitrogen-containing compounds (37.25%), with the relative content of 2-methylpyrazine (roasted, biscuit-like aroma) significantly increasing compared with that of chicken egg yolk. Goose egg yolk had the lowest relative content of hydrocarbons (25.20%). Chicken egg yolk showed a relatively high aldehyde content (29.13%) and exclusively contained 2,5-hexanedione (creamy aroma). Duck egg yolk was characterized by a high benzaldehyde content (bitter almond-like odor). Principal component analysis (PCA) demonstrated clear clustering of volatile compounds from the egg yolks and whites of the four poultry species. Furthermore, 37 differential volatile markers were selected from the yolks based on volcano plot analysis, of which 20 exhibited clear sensory contributions. This study confirms that poultry egg flavor originates mainly from the yolk and reveals that the differences in yolk flavor profiles in eggs from different poultry species are primarily due to variations in the types and contents of aldehydes, hydrocarbons, and sulfur- and nitrogen-containing compounds. The findings provide a scientific basis and technical support for distinguishing the flavor profiles of eggs from different poultry species and for developing high-quality egg products, thereby contributing to the high-quality development of the poultry egg industry.

Key words: poultry eggs; differential analysis; volatile compounds; gas chromatography-olfactometry-mass spectrometry