Preliminary results on the feasibility of producing selenium-enriched pink (Pleurotus djamor) and white (Pleurotus ostreatus) oyster mushrooms: Bioaccumulation, bioaccessibility, and Se-proteins distribution

The consumption of white (Pleurotus ostreatus) and pink (Pleurotus djamor) oyster mushrooms has been high-lighting due to nutritional value and ability to accumulate essential elements, such as selenium (Se). Therefore, the aims of the present study were to evaluate the Se-enriched mushrooms production and enrichment effects on the bioaccessibility of Ca, Cu, Fe, K, Mg, Mn, P, S, Se, and Zn, and proteins and Se-proteins distribution. The Se enrichment of edible mushrooms (white and pink) with different Se(IV) concentrations did not alter the moisture (77 to 89%) and biological efficiency (21 to 27%). The Se total concentration increased significantly in mushrooms cultivated in enriched medium, ranging from 19 +/- 1 mu g g(-1) (white) to 76 +/- 2 mu g g(-1) (pink). It was verified that Se enrichment did not significantly change the total concentration of Ca, Cu, Fe, K, Mg, Mn, S, and Zn of both mushroom species. However, the Se enrichment promoted an increase in the bioaccessible percentage of Fe (7 to 11%), Mg (12 to 13%), P (4 to 6%), S (7 to 12%), and Zn (10 to 14%) for pink oyster mushroom and a decreased in Fe (18 to 28%) and P (7 to 13%) of the white oyster mushroom. In the distribution of proteins, it was verified that the enrichment changed the solubility and distribution of proteins in white oyster (prolamins and glutelins) and pink oyster mushrooms (globulins). Lastly, Se is mainly associated to albumins (white oyster: 4.5 +/- 0.4 mu g g(-1), pink oyster: 9.5 +/- 0.7 mu g g(-1)) and glutelins (white oyster: 4.2 +/- 0.6 mu g g(-1), pink oyster: 11.1 +/- 0.4 mu g g(-1)). These results demonstrate the ability of these fungi to absorb and bioaccumulate Se, favoring the formation of Se-proteins that are more bioaccessible species.