Green and sustainable dual-pathway strategies for high-efficiency photoconversion of ergosterol to vitamin D₂ from agaricus bisporus.

The conversion of ergosterol to vitamin D₂ (VD2) in Agaricus bisporus is still limited by low efficiency. This study integrates a particle size-regulated powder photoconversion pathway and natural deep eutectic solvent (NADES) integrated extraction-photoconversion pathway to achieve a high VD₂ yield. In the powder pathway, combining UV-B irradiation with a median particle size of 130-140 μm maximized VD₂ yield, reaching 2.59% by balancing optical penetration depth, light shielding, and the resulting porous cellular structure. In the extract pathway, the menthol-based NADES system was developed to achieve simultaneous high-efficiency ergosterol extraction (85.41% extraction efficiency) and stabilization, as well as ergosterol photoconversion to VD₂ (4.08% yield), attributed to enhanced cell permeability and hydrogen bonding interactions. The NADES system also enhanced the storage stability of ergosterol and VD₂ by 24.79% and 20.53%, respectively, compared to the ethanol during storage. This work provides green and tunable dual-pathway strategies for developing high-value VD₂-enriched products.