Optimization of ergosterol to vitamin D2 synthesis in Agaricus bisporus powder using ultraviolet-B radiation

Response surface methodology (RSM) was applied to determine the optimum circumstances for conversion of ergosterol to vitamin D-2 via ultraviolet-B (UV-B) in white button mushroom (Agaricus bisporus) powder. Three independent variables, namely, exposure time, ambient temperature, and irradiation intensity were investigated using a central composite rotatable design. The RSM ridge analysis determined the following ideal states: exposure time of 10.4 min, ambient temperature of 26.33 degrees C, and UV-B irradiation intensity of 1.36 W/m(2). A vitamin D-2 content of 741.50 +/- 23.75 mu g/g (the predicted value was 780.4 mu g/g) was obtained under these ideal conditions.