Vitamin D2 (ergocalciferol) can be obtained from fungal biomass through the UV-induced maturation of ergosterol. In this study, Agaricus bisporus caps were used as a model system to investigate ergosterol extraction and subsequent photochemical conversion under controlled conditions. Ergosterol was extracted using ethanol at different solid-to-solvent ratios (1:5 and 1:50) employing long-term extraction and ultrasound-assisted methods, including glass-bead-enhanced ultrasound extraction, following process-intensification approaches. Photoconversion experiments were then carried out under controlled UV irradiation to evaluate conversion dynamics and assess the suitability of extracted ergosterol for vitamin D2 formation, using both model ergosterol solutions and mushroom-derived ethanolic extracts. Kinetic analysis of the photochemical conversion was performed using apparent zero-order and first-order models as simplified representations of the underlying photokinetic behavior, where reaction rates depend on absorbed radiation. This preliminary evaluation of extraction yields, and photochemical kinetics provides process-relevant insights for the development and industrialization of fungal-derived vitamin D2 as an alternative to conventional sources.
