Nutrition and Health, 2007, Vol. 18, pp. 383-389 0260-l 060/07 $10 © 2007 A B Academic Publishers. Printed in Great Britain CHEMICAL PROFILE AND AMINO ACIDS COMPOSITION OF EDIBLE MUSHROOMS PLEUROTUS SAJOR-CAJU F.L. OYETAY0 1 , A.A AKINDAHUNSI 2 AND V.O. OYETAY0 3 1 Biochemistry Dep,artment, University of Ado-Ekiti, Nigeria, 2 Biochemistry Department and Department of Microbiology, Federal University of Technology Akure, Nigeria ABSTRACT Two varieties of Pleurotus sajor-caju, obtained from the wild and cultivated (on shredded corncobs) were separated into cap and stalk and analysed on dry weight basis. The proximate composition (g/1 OOg) showed that both varieties were highly concentrated in crude protein. The cultivated cap (Cc) was found to accumulate higher concentration of crude protein (26.34%) and ash (10.37%) than the wild cap (We), which had higher crude fat (3.90%) and crude fibre (16.32%) concentrations while the wild stalk (Ws) contained the highest concentration of crude fibre (26.14% ). Amino acid analysis showed the mushroom protein to be a rich source of nutritionally useful essential amino acids with leucine as the most abundant occurring in highest concentration (mg/g) in the Cc (64.8±0.24). Methionine and cysteine concentrations were low as confirmed by their chemical scores (0.29-0.59). There was a significant difference (P<0.05) in the distribution of amino acids in the mushroom varieties and parts. The total essential amino acid (TEAA) in the cultivated range between 42.91-43.69% while in the wild it was between 42.90-43.73 % of the total amino acid content. The amino acid concentration was a function of mushroom variety and part selected. INTRODUCTION Edible mushrooms are healthy foods rich in proteins and minerals, poor in calories and fat. They have also shown medicinal values as an ideal food for diabetics, (Geuders, 1974) and contain a number of polysaccharides reported to show antitumor activity (Mizuno, 1999). Cultivation of edible mushroom on agricultural residues is a process that converts materials otherwise considered as waste into valuable human food, (Zhang et al., 2002) a source of commercially important metabolites, (Buswell and Chang, 1993) and a solution to the environmental pollution associated with the current disposal Corresponding author: ovounad@yahoo.com