Moisture state and volatile flavor behavior characterization of Naematelia aurantialba during postharvest in modified atmosphere packaging storage after treated with ultraviolet radiation C

Abstract

Naematelia aurantialba (N. aurantialba), a rare edible mushroom, is valued for its unique texture, rich flavor, and abundant bioactive compounds, including polysaccharides and carotenoids. However, its exceptionally high moisture content makes it highly perishable, leading to rapid quality deterioration, water loss, and undesirable flavor changes during storage. In our previous study, we established the optimal composite storage conditions for N. aurantialba, where 0.19 kJ/m² ultraviolet C (UVC) irradiation was applied under modified atmosphere packaging (MAP) conditions (oxygen permeability: 4081 mL m^-² d⁻¹ atm⁻¹) to effectively maintain postharvest quality. This study builds upon those findings by investigating the effects of UVC treatment on moisture migration and volatile compounds in N. aurantialba, comparing the UVC-treated group with a non-UVC control group. Low-field nuclear magnetic resonance (LF NMR), magnetic resonance imaging (MRI), gas chromatography-mass spectrometry (GC-MS), and an electronic nose (E-Nose) were employed to analyze water migration and volatile compound dynamics. The results indicated that UVC treatment significantly slowed free water migration, reduced moisture loss (2.46 ± 0.37 % at the end of storage), enhanced key flavor compounds such as alcohols and esters, and inhibited undesirable odors. Sensory evaluations confirmed improvements in flavor, texture, and overall acceptability. These findings provide new insights into the physiological responses of N. aurantialba to UVC treatment, offering a scientific basis for optimizing postharvest storage strategies and improving quality retention in high-moisture edible fungi.