Ultraviolet-B radiation, mushrooms, and vitamin D: From technology to bioavailability

From the paper

Abstract

We describe an efficient technology to obtain vitamin D₂-enriched mushroom powder by exposing postharvest shiitake mushrooms (Lentinula edodes) to UV-B radiation. UV-B exposure took place in a self-designed semi-industrial facility with the required safety measures. The highest vitamin D₂ content (1000 IU g⁻¹ DM) was found when a total UV-B dose of 24 kJ m⁻² was distributed in two different moments of the process (75% on sliced fresh mushroom and the remaining 25% on the dry powder). Similar results were obtained in king oyster (Pleurotus eryngii) and Portobello button (Agaricus brunnescens) mushrooms, indicating that the developed technology could generally be used to produce vitamin D₂ supplements from mushrooms. In addition, the same method increased the vitamin D₂ content in shiitake by-products, which could be used for animal feed. The microbiological, toxicological, and nutritional quality of the enriched mushroom preparations were confirmed to ensure a safe consumption. To determine the vitamin D bioavailability in humans, the enriched shiitake powder was encapsulated using 600 mg per capsule, which was equivalent to the minimum daily intake of vitamin D for adults. The capsules were ineffective in improving serum 25-hydroxyvitamin D status, but prevented an excessive decrease in this parameter due to winter conditions.