Abstract

PROXIMATE, PHYTOCHEMICAL, ANTIOXIDANT AND ANTIMICROBIAL PROPERTIES OF MARKET SAMPLES OF PLEUROTUS TUBER REGIUM FROM OWERRI, NIGERIA

*Onuegbu N.C., Ihediohanma N.C., Uzoh G.U. and Isaiah N.D.

ABSTRACT

Three different market samples of Pleurotus tuber regium (sclerotia) were obtained from different locations around Owerri, Nigeria. The samples were subjected to proximate, functional and phytochemical analysis. The antioxidant and antimicrobial properties were also investigated. The samples had low fat content (1.95-3.96%) and high carbohydrate content (67.42-74.03%) which comprised mainly of dietary fibre (39.8-48.5%). The oil absorption capacity (OAC) was 2.36-2.57, g/g for the sclerotia samples while the water absorption capacity (WAC) for the samples was 3.39 - 3.91g/g. The alkaloid and flavonoid contents ranged from 1.66 to 2.137% and 0.51-0.93% respectively in all the samples, while tannin content was 0.14-0.52%. At the concentration of 1mg/ml the ethanolic extract the value of free radical scavengingactivities was 67.5% and was 100% at 2mg/ml concentration. The minimum inhibitory concentration was 12.5mg/ml for Staphylococccus aureus and Bacillus spp and 6.25mg/ml for the Salmonella spp.

Keywords: Pleurotus tuber regium, proximate composition, functional properties, antioxidants, antimicrobial.