Enhanced antioxidant properties as a function of selenium uptake by edible mushrooms cultivated on selenium-accumulated waste post-harvest wheat and paddy residues

Background Majority of the post-harvest agri-residuesfrom agricultural activity in Punjab, India, is burnt in thefield resulting in the loss of soil fertility and release of largeamounts of air pollutants. In an effort to reutilize theselenium-accumulated waste wheat and paddy straw fromseleniferous region of Punjab, two varieties of ediblemushrooms, Pleurotus sajor-kaju and Volvariella volvacea,were cultivated on Se-rich wheat and paddy straw,respectively.Results Se concentration in Se-enriched P. sajor-kaju andV. volvacea (43.5 ± 2.1 and 35.0 ± 1.1 lg/g) was significantlyhigher than control (5.2 ± 1.0 and 5.57 ± 0.07 lg/g), respectively. The antioxidant activity as depicted bytotal phenol content, total oxidant activity, DPPH scavenging,metal chelation and lipid peroxidation inhibitingactivity of extracts from Se-fortified mushrooms weresignificantly higher (p.05 to p.001) than controlmushrooms.Conclusion The increased antioxidant activity is attributedto be induced by the accumulation of selenium bythese species of mushrooms, indicating the antioxidantnature of selenium in biological systems. Further, thepresent study also demonstrates the use of Se accumulatedagricultural residues as substrates for producing Se-richmushrooms as potential sources for Se supplementation/nutraceutical applications.