Insights into the Variation of VOCs in the Maillard Reaction Products Derived from Chinese Black Truffle (<i>Tuber indicum</i>) Enzymatic Hydrolyzates Using E-Nose, HS-SPME-GC-MS, HS-GC-IMS Coupled with Chemometric Approaches

To enhance the aroma complexity and commercial potential of Chinese black truffle (Tuber indicum), enzymatic hydrolyzates (EH) were subjected to Maillard reaction (MR) with xylose/cysteine under varying temperatures (90–130 °C). Volatile organic compounds (VOCs) in MR products (MRPs) were characterized using an E-nose, HS-SPME-GC-MS, and HS-GC-IMS coupled with chemometrics (PCA, OPLS-DA). MR significantly increased VOC diversity (216 compounds identified vs 82 in EH), with sulfur-containing compounds and heterocyclics emerging exclusively in MRPs. Temperature critically influenced VOC profiles: 130 °C (MRPs130) yielded the highest VOC abundance and key odorants, as confirmed by the odor activity value (OAV) analysis. Sankey diagrams visualized a flavor shift from mushroom/earthy notes in EH to enhanced fruity, green, and roasted nuances in MRPs130. This strategy effectively improves the Chinese truffle aroma, offering theoretical and practical insights for value-added processing.