Appropriate UV-C treatment maintains the postharvest quality and flavor characteristics of Thelephora ganbajun during storage

Thelephora ganbajun is highly susceptible to postharvest quality deterioration, including water loss, softening, color deterioration, microbial proliferation, and flavor loss. This study evaluated the effects of UV-C treatments (0, 0.25, 0.5, and 1.0 kJ/m 2 ) on the storage quality, microbial changes, sensory attributes, and flavor-related metabolites of T. ganbajun stored at 4 °C. During storage, hardness and springiness decreased, whereas weight loss, malondialdehyde content, and microbial populations increased. Among the treatments, 0.5 kJ/m 2 UV-C exhibited the best overall preservation effect, maintaining texture and color stability, reducing weight loss and malondialdehyde accumulation, and sustaining higher superoxide dismutase, catalase, and C-S lyase activities. Although 1.0 kJ/m 2 UV-C showed stronger microbial inhibition, its overall quality-maintaining effect was inferior to that of 0.5 kJ/m 2 . Taste, sensory, and metabolomic analyses further indicated that 0.5 kJ/m 2 UV-C helped maintain umami-related compounds and modulated key aroma-active volatiles associated with aroma quality. Non-volatile metabolomics suggested that these effects were associated with umami precursors, lipid metabolism, nucleotide sugars, antioxidant-related metabolites, and texture maintenance. These findings support 0.5 kJ/m 2 UV-C as a promising non-thermal strategy for preserving fresh T. ganbajun during cold storage.