Sterol and vitamin D-2 concentrations in cultivated and wild grown mushrooms: Effects of UV irradiation

Raw and processed mushroom samples including wild grown (chanterelles and king boletc) and cultivated samples (white and brown button, portabella, shiitake, oyster) were bought from the food market and analysed for sterols and vitamin D-2 contents. The different commercial mushrooms selected are abundant in almost every Swedish and European supermarket or Outdoor market. Ergosterol was the most abundant sterol found in mushrooms present in somewhat higher concentrations in cultivated mushrooms (4.0-5.0 mg/g dry matter (d.m.)) than those found in wild mushrooms (1.7-3.5 mg/gd.m.). In addition, three closely related minor sterols, including ergosta-7,22-dienol, ergosta-5,7-dienol, and ergosta-7-enol were identified. Chanterelles and king bolete were found to be good sources of vitamin D-2 (0.7-2.2 mu g/g d.m.) compared With Cultivated Mushrooms that had a low content (< 0.1 mu g/g d.m.). Canned samples of Agaricus bisporus/white were slightly lower in ergosterol and vitamin D, compared to fresh samples. Irradiation with UV light in the A region (366 nm) only slightly affected ergosterol and vitamin D-2 content. In contrast, irradiation with UV light conducted in the C region (254 nm, 0-2 h, 20 cm distance) for fresh white button mushrooms and freeze-dried chanterelles resulted in nonsignificant decrease in ergosterol content, whereas vitamin D-2 increased up to 9-fold (Cantharellus tubaeformis) and 14-fold (A. bisporus/white), respectively. (c) 2006 Swiss Society of Food Science and Technology. Published by Elsevier Ltd. All rights reserved.