Insights into VOCs variation derived from Chinese black truffles (Tuber indicum) between grades via E-nose, HS-SPME-GC-MS, and HS-GC-IMS

This study investigated volatile organic compound (VOC) variations across commercial grades (G1, G2, G3) of Chinese black truffles ( Tuber indicum ) using electronic nose ( E -nose), headspace solid-phase microextraction gas chromatography–mass spectrometry (HS-SPM E -GC–MS), and headspace gas chromatography-ion mobility spectrometry (HS-GC-IMS). E-nose analysis revealed significant differences in sulfur-containing and terpenic compounds between grades. HS-SPME-GC–MS identified 95 VOCs, with G1 exhibiting the highest diversity (75 compounds) and unique markers like 2-butanone. Orthogonal partial least squares-discriminant analysis (OPLS-DA) highlighted 86 discriminatory VOCs (VIP > 1). Odor activity value (OAV) analysis showed G1 had the strongest aroma intensity, driven by esters (ethyl isobutyrate, OAV = 6574) and alcohols (1-octen-3-ol, OAV = 3444). Higher-grade truffles (G1) contained distinct sulfur compounds absent in lower grades. This multi-technique approach provides a biochemical basis for refining truffle grading standards beyond morphological criteria.