CHEMICAL COMPOSITION AND THE ANTIOXIDANT ACTIVITY OF TWO EDIBLE MUSHROOMS

The proximate composition and minerals contents of two edible mushroom (Pleurotus ostreatus and Agaricus bisporus) flours used in Egypt were investigated. Also, ethyl acetate, ethanol, methanol and distilled water were used to fractionate soluble compounds from the mushrooms in ascending polarity by sequentially extracting. As well as, total phenolic, total flavonoid compounds and the antioxidants activity for these extracts were investigated. The percentage moisture content ranged between 90.47% in Pleurotus ostreatus to 90.55% in Agaricus bisporus. The crude protein ranged from 3.25% in Pleurotus ostreatus to 3.48% in Agaricus bisporus. Total carbohydrates ranged from 5.23% in Agaricus bisporusto 5.35%±0.03 in Pleurotus ostreatus. The most abundant mineral element is potassium (ranging from 2376.8 to 2820.5 mg/100 g on dry weight base (DW) for Agaricus bisporus and Pleurotus ostreatus, respectively) followed by Phosphorus (ranging from 537 to 754 mg/100 g on DW for Pleurotus ostreatus and Agaricus bisporus, respectively). The antioxidant activity of different extracts for two mushrooms (Agaricus bisporus and Pleurotus ostreatus) increased gradually as concentration increases. These results compatible with those results recorded for total phenolic compounds of investigated mushroom. In conclusion, mushrooms, in spite of the great variability observed among species, represent an interesting food item that can contribute to the formulation of a well-balanced diet.