Journal of Food Processing & Technology

Abstract

Major, Minor and Toxic Minerals and Anti-Nutrients Composition in Edible Mushrooms Collected from Ethiopia

Woldegiorgis AZ, Abate D, Haki GD and Ziegler GR

Major (Na, K, Ca, Mg, P), minor (Mn, Cu, Fe, Zn) and toxic (Pb, Cd) minerals composition of twelve edible mushrooms (Pleurotus ostreatus, Lentinula edodes, Agaricus bisporus #1 (fresh), Agaricus bisporus #2 (canned), Agaricus campestris, Laetiporus sulphureus, Termitomyces clypeatus, Termitomyces microcarpus #1, Termitomyces microcarpus #2, Termitomyces aurantiacus, Termitomyces letestui and Termitomyces species) collected from three regions of Ethiopia were analyzed. The samples were further investigated for their antinutrients (phytate and condensed tannin) to determine bioavailability of minerals. All the results are expressed in dry basis (db). The major minerals concentration (mg/g) ranged: Na (0.41-34.8), K (3.66-42.4), Ca (0.29-6.45), Mg (0.57-2.12) and P (0.71-2.82). The minor (mg/kg) ranged: Fe (32.5-6835.9), Zn (26.6-87.6), Cu (5.69-45.9) and Mn (0.96-138.6). The toxic metal lead was detected (1.52-18.0 mg/kg), indicating most of the mushrooms samples exceeded the weekly tolerance limit set for Pb with more proportion in wild than cultivated mushrooms. Cadmium was detected only in A.campestris (4.08 mg/kg). The anti-nutrients (mg/100 g) were significantly varied with phytate ranged from 31.3 to 242.8 and condensed tannin from 4.81 to 31.7. The calculated molar ratio between phytate and Fe, Zn and Ca was above the suggested critical values indicating the bioavailability of Fe, Zn and Ca to be high. In conclusion, the results imply that the edible mushrooms have high concentrations of essential minerals with lower anti-nutrients that make them bioavailable to the human body. Although, the consumption of some contaminated mushrooms should be avoided.