Metabolomic insights into the dynamic changes of volatile and non-volatile compounds in Butyriboletus roseoflavus during vacuum drying

The dynamic changes in flavor and quality of <i>Butyriboletus roseoflavus</i> during vacuum drying at 60 °C were systematically characterized using sensory evaluation, colorimetry, targeted free amino acid analysis, and untargeted metabolomics. Fresh mushrooms exhibited bright color with predominant mushroom and earthy aromas, while prolonged drying induced color darkening and shifted aroma toward fatty and roasted notes. Concurrently, drying significantly increased free amino acid levels, contributing to enhanced taste. Volatile analysis showed that these compounds were most abundant in fresh samples and decreased over the course of drying, with major aroma-active compounds such as 1-nonen-3-one, 2-methoxy-3,5-dimethylpyrazine, and 2-octenal declining as well. The 0-3 h and 6-9 h intervals were identified as critical periods showing the most pronounced changes in non-volatile metabolites. KEGG pathway enrichment analysis identified an interconnected network of metabolic pathways involved in quality formation during drying, including amino acid metabolism, the tricarboxylic acid cycle, one‑carbon metabolism, and secondary metabolism. This study provides the first comprehensive insight into the dynamics of flavor compounds in <i>B. roseoflavus</i> under vacuum drying, providing a theoretical framework for future research on its flavor chemistry and industrial processing.