Abstract

Vitamin D, accompanying with its nutritional and physiological benefits is also known to protect against severe respiratory infections. Mushroom mycelia can be developed as potential Vitamin D2 rich vegan source by converting its inherent ergosterol into Vitamin D2 through ultraviolet-B (UV-B) irradiation. In the present study, Pleurotus eryngii mycelia were cultured through submerged fermentation and the ideal UV-B irradiation conditions were determined for Vitamin D2 formation in harvested mycelia using response surface methodology. The effects of three independent variables, namely, temperature (20–40°C), ultraviolet-B intensity (0.6–1.2 W/m2 ), and time of exposure (10–30 min) on Vitamin D2 were investigated. Under optimal conditions (ambient temperature, 24.29°C, UV-B intensity, 1.099 W/m2 , and exposure time, 23.88 min), the Vitamin D2 got increased to 329.43 μg/g (model predicted value was 346.84 μg/g), while in the control (untreated mycelia), Vitamin D2 was not detected. Along with vitamin D enhancement, β-glucan content was also improved from 26.02 to 29.43 g/100g. This UV irradiated mycelia could be utilized as a potential source for Vitamin D2 rich functional food items and health supplements.

Key words: Submerged fermentation, vitamin D2, Pleurotus eryngii, UV-B irradiation, RSM