Changes in the Quality Characteristics of Gastrodia Elata During Traditional Processing: Insights from Multi-Omics Integration

Gastrodia elata Bl. (GE), a representative medicine–food homology material, requires appropriate processing prior to food application to meet established medicinal quality standards. However, the effects of different traditional processing methods on its quality attributes remain insufficiently elucidated. In this study, three representative processing methods, steaming, moistening, and bran-frying, were systematically compared to evaluate their impact on the structural, compositional, and flavor characteristics of GE. The results demonstrated that processing markedly altered both the physical structure and chemical composition of GE. Moistening caused minimal disruption to the native tissue architecture and largely preserved the free-water distribution pattern. Notably, gastrodin and p-hydroxybenzyl alcohol contents reached 0.38% and 4.16%, respectively, the highest among all treatments, while the overall flavor profile remained closest to that of fresh GE. In contrast, bran-frying induced pronounced dehydration and structural densification, with volatile compounds and differential metabolites accounting for 72.83% and 41.01%, respectively. This treatment also exhibited elevated levels of total phenolics, flavonoids, and protein. Steaming, by comparison, promoted starch gelatinization and water redistribution, shifting the flavor profile from a delicate herbal note toward enhanced umami, floral, and mildly roasted characteristics. Overall, these findings reveal that processing-induced structural remodeling and changes in water state play critical roles in regulating the quality attributes of GE. By integrating structural characterization, water-state analysis, and multi-omics data, this study provides a systematic understanding of the formation of GE quality attributes under different processing methods, offering a theoretical basis for quality control and process optimization.