The Basidiomycete fungus Agaricus brasiliensis (A. blazei), known as “sun mushroom” is a medicinal mushroom. They are popularly known as ‘Cogumelo do Sol’ in Brazil and ‘Himematsutake’ in Japan. They are native to Brazil and have been traditionally used as a health food source in Brazil. In the mid-1960s, spores of A. blazei were taken to Japan for commercial cultivation and research (Hetland et al.,2008). It has been reported that 200,000 to 400,000 kg of the dried body of A. blazei is produced every year in Japan (Kimura, 2005). Most research was focused on the therapeutic effects of these medicinal mushrooms, but little information is available about their antioxidant properties (Mau et al., 2002).