UV-Induced Nutritional Transformation of Mushrooms: From Molecular Shifts to Health Outcomes.

This study establishes ultraviolet (UV) irradiation as a promising postharvest strategy for enhancing the nutritional quality of edible mushrooms. However, its efficacy depends strongly on wavelength, dose, tissue geometry, species physiology, and storage conditions. Evidence indicates that UV-driven changes follow distinct mechanistic routes: photochemical conversion of ergosterol to vitamin D₂, oxidative signaling in phenolics and antioxidants, stress-mediated retention of water-soluble vitamins, and matrix-level alterations in polysaccharides and cell-wall structures. These responses were interpreted through unified pathways linking UV dose to molecular targets and physiological outcomes. A major limitation in previous studies is inconsistency in light parameters and incomplete reporting of UV conditions. To address this, quantitative modeling using response surface methodology (RSM) was applied to integrate heterogeneous datasets. A weighted meta-analysis revealed species- and geometry-specific UV-B optima. For sliced Agaricus bisporus, an optimum was identified at 16,664 J/m2 and 3.2 W/m2, yielding 16.27 μg/g vitamin D₂ (95% CI: 13.69-18.85). These values fall within observed experimental ranges, confirming model validity. Dose-response patterns consistently showed that moderate UV exposure enhances vitamin D₂, whereas excessive exposure leads to nutrient degradation or plateau effects. Human and animal trials demonstrate that UV-treated mushrooms significantly increase serum 25(OH)D₂ levels without adverse effects, establishing them as a bioavailable and safe dietary source of vitamin D₂. Regulatory bodies have confirmed the safety of UV-treated A. bisporus powder, with no elevation in agaritine levels. These findings support the inclusion of UV-treated mushrooms in evidence-based nutritional interventions to address global vitamin D deficiency.