Effects of UV-C treatment and cold storage on ergosterol and vitamin D2 contents in different parts of white and brown mushroom (Agaricus bisporus)

Effects of ultraviolet-C (UV-C) treatment (0.5, 1.0 and 2.0kJ/m(2)) and cold storage on ergosterol and vitamin D2 content in different parts of white and brown button mushrooms (Agaricus bisporus) were investigated. UV-C treatment did not significantly affect ergosterol content in the caps and stems of the two mushrooms, but ergosterol content increased significantly during 14days cold storage. Vitamin D2 content in the caps and stems of two mushrooms significantly increased as UV-C dose increased, and 2.0kJ/m(2) UV-C showed the best result. During cold storage, vitamin D2 content in the caps of the two mushrooms decreased from day 1 to day 7, and then kept stable until day 14, but vitamin D2 content in the stems of brown mushrooms kept increasing for the whole 14days period. UV-C could increase vitamin D2 contents in both caps and stems of white and brown mushrooms without significantly affecting ergosterol content.