Nutritional Attributes and Nonvolatile Taste Components of Medicinally Important Wild False Earthstar Mushroom, Astraeus hygrometricus (Agaricomycetes), from India.

Abstract

Fruiting bodies of Astraeus hygrometricus mushroom grown wild in the forests of Jharkhand, India were investigated for their proximate nutritional composition and taste imparting nonvolatile components. Fruiting bodies contained good amount of total carbohydrates (55.76%), reducing sugars (15.98%), protein (16.02%), and dietary fiber (39.78%) but were low in fat (3.5%), ash (3.8%), and energy (159.5 kcal). Fatty acids were represented by monounsaturated C18:1n9c oleic acid (4.59%) and saturated C16:0 palmitic acid (2.63%). In vitro digestibility of protein is an indicator of its availability to human body and A. hygrometricus has 33.2% in vitro digestibility. Among the minerals found (mg/100 g), potassium (K, 1930.0) was major mineral followed by calcium (Ca, 443.0), magnesium (Mg, 434.0), sodium (Na, 155.0), iron (Fe, 127.0), manganese (Mn, 16.0), and selenium (Se, 1.60). Pro-vitamin D2 (ergosterol) was also determined to be 1.09 mg/g. Analysis of soluble sugars indicated that mannitol (11.22 mg/g) was the major sugar alcohol conferring sweetness to the fruiting bodies. Among total free amino acids (8.20 mg/g), seven essential amino acids (3.9) and eight nonessential amino acids (4.3) were detected. Leucine (0.92) and tyrosine (0.98) were the major essential and nonessential amino acids, respectively. Aspartic (0.61) and glutamic acid (0.63) were also present in AH and responsible for its MSG like taste. Thus, A. hygrometricus is a good source of free essential amino acids and selenium, which is not synthesized by humans. Meaty flavor of the fruiting body of A. hygrometricus was mainly due to umami 5'-guanosine monophosphate (2.43 mg/g). Sweet taste and meaty flavor of the mushroom were due to nonvolatile taste components including soluble sugars and polyols, MSG like aspartic and glutamic acid, and umami 5'-nucleotide. Overall A. hygrometricus proved its edibility as a tasty and nutritional food.