THE EFFECT OF DIFFERENT SUBSTRATES ON THE PHENOTYPE, NUTRITIONAL, PHYTOCHEMICAL COMPOSITION AND ANTIOXIDANT ACTIVITY OF PLEUROTUS PULMONARIUS

                                                                              ABSTRACT

Mushroom has been an important food to man for millennia. Several species of Pleurotus has been cultivated successfully on different substrates including Palm bunch, Saw dust and Corn cob. Pleurotus pulmonarius has also been cultivated but there is a gap in knowledge as to the effect of different substrates on the phenotypic, nutritional, phytochemical and antioxidant activity of Pleurotus pulmonarius. The sole aim of this work is to bride this gap. Phenotypically, there is no significant difference (p≤0.05) in the number of days for full mycelia colonization for Saw dust and Palm bunch. For all substrates, primordial initiation days are statistically the same. Palm bunch producedthe most number of fruiting bodies (36.00±15.50), making it the substrate yielding fruits with the highest fruit weight (216.00±62.92). Protein and moisture content was higher in Pleurotus pulmonarius grown on Palm bunch (25.61±0.11, 4.09±0.01 respectively), while carbohydrate was higher in Saw dust (62.85±0.09). Mineral composition varied with the highest value observed for potassium in Pleurotus pulmonarius grown on Saw dust and Palm bunch (3.93±0.01, 3.90±0.03), there is therefore no significant difference at (p≤0.05). Pleurotus pulmonarius has low phytochemical composition, but its free radical scavenging ability against DPPH free radicals was high (73.57±0.27, for Pleurotus pulmonarius grown on Palm bunch and 28.22±0.39 for Saw dust). ABTS* scavenging ability was highest in Palm bunch (38.45±0.25). These varying differences in the composition of Pleurotus pulmonarius grown on Palm bunch, Saw dust and Corn cob ratifies the hypothesis that substrates influenced its growth and composition.