Off-Odor Profiles of Fresh Gastrodia elata Tubers From Five Varieties: Identification of Key Odor-Active Compounds...

Fresh tubers of Gastrodia elata (GE), valued for both their food and medicine properties, have limited applications due to unpleasant off-odor. In this study, five representative fresh GE varieties were analyzed for the first time using quantitative descriptive analysis (QDA). Seven off-odor attributes were identified, with horse urine-like odor being the most intense, followed by acidic and starchy notes. Headspace solid-phase microextraction gas chromatography-mass spectrometry (HS-SPME-GC-MS) detected 67 volatile organic compounds, 17 of which were present in all varieties. Nine shared odor-active compounds were identified by GC-O-MS. Odor activity value (OAV) analysis revealed four key contributors: (E,E)-2,4-decadienal, (E)-2-octenal, 2-phenylacetaldehyde, and p-cresol. Sensory interaction analysis using Feller's additive model demonstrated both binary synergistic and additive effects among these compounds. Traditional processing methods reduced off-odor intensity, with ethanol treatment being the most effective (reducing horse urine-like odor by more than 50%). After processing, the three aldehydes became undetectable, whereas p-cresol levels were substantially decreased, though they still contributed to a residual off-odor. Unlike previous studies that mainly focused on dried GE products, this research characterizes the off-odor profile of fresh GE tubers. It provides a theoretical foundation for regulating off-odor-related gene expression, developing effective deodorization strategies, and facilitating the development of novel GE-based functional foods.