GC–MS-based metabolome classification of sturgeon caviar and fish roe samples reveals unique caviar signatures, interspecies and gender variabilities

Caviar/roe, widely valued in modern cuisine, is little characterized regarding its complete metabolite composition. Existing studies focused primarily on specific classes e.g., lipids and proteins. This study represents the first extensive GC-MS metabolite profiling of 48 caviar/roe samples from 10 commercially important taxa, including male and female aquatic animals. One hundred thirty-nine primary and secondary metabolites were identified and quantified belonging to fatty, amino, and organic acids, sugars, nitrogenous compounds, and steroids/terpenoids. Multivariate data analysis further uncovered clear interspecies and gender-specific metabolic differences. OPLS-DA highlighted palmitic acid and cholesterol as discriminative markers for sturgeon caviar, while serine and urea distinguished salmon roe. Gender differences were evident in Charybdis natator roe, with males enriched in amino acids and females in fatty metabolites. This comprehensive caviar/roe metabolite map proposes male gilt-head bream Sparus aurata and female common cuttlefish Sepia officinalis for further investigation of their potential functional food applications, driven by their rich omega-3 PUFA levels. Specifically, S. officinalis roe presents good fat source being rich in γ-tocopherol, with favorable n-3/n-6 ratio. The rich content of pyroglutamic acid in S. aurata may contribute to its characteristic umami taste encouraging further sensory analysis. The findings strengthen the molecular basis for improved quality assessment and nutritional labeling of caviar/roe products.