Effect of the Edible Mushroom, Pleurotus tuberregium on the Cyanide Level and Nutritional Contents of Rubber Seed Cake

In this study, Rubber Seed Cake (RSC) was treated with the mycelium of the mushroom (Pleurotus tuberregium) so as to assess the effect of its enzymatic ability on the cyanide level and nutritional value of the rubber seed cake and hence enhance its agricultural and industrial applications. Levels of cyanide in the RSC were determined with the use of the Picrate kit paper method. Results from this study indicates that treating the RSC with the mushroom mycelium yielded about 81% reduction in the total cyanogens content after 96 hours at room temperature. The initial cyanide concentration of 500ppm in the freshly obtained rubber seed cake was reduced to a level of 5ppm for the undefatted RSC and from 300ppm to 4ppm for the defatted RSC. The values obtained for the treated RSC were found to be below the limit of 10ppm as set by FAO/WHO regulatory bodies. The proximate analysis after fermentation with the mushroom mycelium revealed that the protein content of the RSC increased significantly (p = 0.01) from a value of 29.36% to a value of 39.27% further enhancing its use as feed for livestock.