Taste and odor metabolomics of Schisandra chinensis flesh and seeds: integration of sensory evaluation, electronic tongue, LC-QTOF-MS/MS, VirtualTaste, and HS-GC-IMS.

BACKGROUND: The fruit of Schisandra chinensis is a functional berry with a long application history and a complex flavor profile. METHODS: To differentiate the flavor profiles of Schisandra chinensis flesh and seeds, an integrated analytical strategy combining sensory evaluation, electronic tongue, LC-QTOF-MS/MS, VirtualTaste, and HS-GC-IMS was developed. RESULTS: Sensory evaluation and electronic tongue revealed that the flesh was characterized by sourness and lemon-like odor, while the seeds exhibited bitterness, pungency, and Sichuan pepper odor. LC-QTOF-MS/MS identified 57 potentially taste-active compounds. VirtualTaste prediction results revealed that citric acid and malic acid had high potential to produce sour taste, and these two acids might be major contributors to the sour sensation of the flesh. The contents of citric acid and malic acid in flesh were higher than those in seeds. Lignans exhibited high probabilities of bitter taste attribution in seeds. It was inferred that lignans such as schisantherin A, schisandrin A, and schisandrin B partially contributed to the bitter taste of seeds. These compounds accumulated abundantly in seeds and possessed certain bioactivities. The contents of schisantherin A, schisandrin A, and schisandrin B in seeds of the 18 sample batches ranged from 2.24-3.61, 2.91-4.06, and 3.23-4.33 mg/g, respectively. HS-GC-IMS analysis identified a total of 76 volatile compounds. Among them, γ-terpinene, 3-carene, β-pinene, and other components were more abundant in seeds than in flesh, and these substances were likely the key compounds responsible for pungency and the Sichuan pepper odor. CONCLUSION: This study clarified the differential distribution of flavor compounds in the fruit of Schisandra chinensis, providing key data for the separate utilization of the flesh and seeds.