Bioavailability Analysis of Oxalate and Mineral Content in Selected Edible Mushrooms

Total, soluble, insoluble oxalate and mineral content of 20 edible mushrooms were measured using spectroscopic and enzymatic methods. Total oxalate content ranged from 45 (Hericium erinaceus) to 104 (Morchella conica), mg/100 g dry matter (DM), while the soluble oxalate levels ranged from 34 (Lactaius delicious) to 65 (Phellinus florida) mg/100g DM but not detected in Hericium erinaceus, Sparassis crispa, Geastrum arinarius, Boletus edulis, Helvella crispa, and Ganoderma lucidum respectively and very low in Lactaius delicious (34), Russula brevepis (35), and Cantharellus clavatus (37) mg/100g DM. The Ca, P, K and Mg content showed range of 1.35-12.56 mg/g for Ca, 1.22-3.82 mg/g for P, 15.4-25.4 mg/g for K and 1.19-4.71 mg/g for Mg. Overall, the percentage of soluble oxalate content of the selected mushrooms ranged from 34 to 65% of the total oxalate content which suggests that, the selected edible mushrooms presents no risk to people liable to kidney stone formation while other foods like some spices and vegetables can supply significant amounts of soluble oxalates and therefore should be used in moderation as good vegetable, which might be important for human nutrition.