Escalating\nVitamin D<sub>2</sub> Content in Fresh\nSporocarps of Elm Oyster Mushroom Hypsizygus ulmarius (Bull.) Redhead (Agaricomycetes) Using Ultraviolet Irradiation and\nAssessment of Its Stability, Antioxidant Capacity, Color, and Te

Mushrooms\nare widely recognized as a superfood, being the only\nnatural source of vitamin D<sub>2</sub>, which makes them a valuable\ndietary food. Their popularity is rapidly increasing in the current\nera of heightened health awareness. The present study examined the\neffect of UV-B and UV-C irradiation on the vitamin D<sub>2</sub> content,\nits stability, antioxidant capacity, color, and textural properties\nof Hypsizygus ulmarius. The results\nrevealed that the initial vitamin D<sub>2</sub> concentration in untreated\nsamples was 74.82 ± 0.09 μg/100 g dw. After 90 min of UV-B\nexposure, the vitamin D<sub>2</sub> content peaked at 6813.39 ±\n0.04 μg/100 g dw. However, UV-C irradiation first led to a rise\nin vitamin D<sub>2</sub> levels, reaching their highest point (388.30\n± 0.01 μg/100 g dw) after 45 min, followed by their subsequent\ndecline. Stability analysis showed that freeze-dried mushroom powder\nretained more vitamin D<sub>2</sub> than fresh sporocarps after 7\ndays of storage at 4 °C. The UV-B treatment significantly enhanced\nantioxidant properties, increasing TAA (35.84%), DPPH (17.77%), ABTS\n(11.57%), and FRAP (18.36%) values. The color and texture of the samples\nalso changed post-irradiation, with notable increases in hardness,\nspringiness, cohesiveness, and color intensity, alongside a decrease\nin whiteness. The study concluded that UV-B irradiation effectively\nboosts the vitamin D<sub>2</sub> content and antioxidant capacity\nof H. ulmarius besides inducing some\nalterations in its optical and textural properties.