Proximate Nutrient Composition and Antioxidant Properties of Pleurotus sapidus 969 Cultivated on Agave sisalana Saline Solid Waste
Mutemi Muthangya *
Department of Biochemistry, South Eastern Kenya University, P.O.Box 170 – 90200, Kitui, Kenya.
Mzee J. Amana
Department of Biochemistry, Pwani University, P.O.Box 195 - 80108, Kilifi, Kenya.
Suhaila O. Hashim
Department of Biochemistry, Pwani University, P.O.Box 195 - 80108, Kilifi, Kenya.
Anthony M. Mshandete
Department of Molecular Biology and Biotechnology, College of Natural and Applied Sciences, University of Dar es Salaam, P.O.Box 35179, Dar es Salaam, Tanzania.
Amelia K. Kivaisi
Department of Molecular Biology and Biotechnology, College of Natural and Applied Sciences, University of Dar es Salaam, P.O.Box 35179, Dar es Salaam, Tanzania.
*Author to whom correspondence should be addressed.
Abstract
Effects of pure and mixed substrates of sisal waste, grass (Panicum coloratum) and a combination of the two substrates at 50:50 (w/w) on nutritional composition, minerals and antioxidant potential of sun-dried Pleurotus sapidus 969 were investigated in the present study. To determine the proximate chemical composition and antioxidant properties of the samples, standard analytical procedures were employed. Moisture content, crude protein and crude fibre ranged between 11.09-12.80%, 6.4-6.6% and 18.3-30.5%, respectively. Macro elements Ca, Mg, Na, K, and P were also found in substantial amounts with K being present in an exceedingly higher amount (541.3-657.1 mg/100g) than the other macro minerals. The samples from the three substrates contained antioxidant β-carotene (4.6-6.0 mg/100g), lycopene (4.9-5.1mg/100g), Vitamin C (5.2-5.6 mg/100g), phenols (361.0-859.0 mg of GA/g) and flavanoids (33.5-64.0 mg RE/g).Mushroom harvested from mixed substrates contained better nutritional qualities than the pure substrate, although the phenolic content in mushrooms cultivated on sisal substrate was higher. The results further showed that, all the extracts exhibited scavenging ability and metal chelating activity. The findings showed that Pleurotus sapidus 969 is rich in nutrients, macro minerals as well as natural antioxidant which could be explored for pharmaceutical applications.
Keywords: Sisal, antioxidant, free radicals, Pleurotus, flavanoids, phenols