Optimization of Crude Protein Production and Reduction in Cyanide Content of Cassava Peels by Pretreatment with Aspergillus Niger Anl301

摘要

Aspergillus niger ANL301 B-1 β-glucosidase was investigated on its effectiveness in optimizing protein contents and reduction in cyanide content of cassava peels. Freshly harvested cassava tubers peels were dried in oven at 70°C for 36 hours and milled into fine particles using micro millers. Two sterilized conical flasks (250 ml), each containing 50 g of the cassava peel flour in triplicates were prepared. Thirty (30) ml of sterile basal medium was added into each flask and thoroughly mixed. The flasks and their contents were sterilized by placing in boiling water at 100°C in a GFL brand water bath for 5 minutes and in the autoclave at 121°C for 15 min. After cooling, 1 ml of spore suspension of A. niger was aseptically introduced into the first set of the flasks plugged with cotton wool and dried in the oven at 600°C for 24 hrs. The second set of flasks had no inoculums, were plugged with cotton wool and dried at room temperature. Results showed that fermentation of cassava peels by solid state fermentation using the A. niger significantly (P0.05) enriches the protein content of the waste and drastically lowering the cyanide concentration. The significant changes in crude protein and cyanide contents after fermentation suggests it could be used as a good source of protein in compounding animal feeds. These findings will facilitate the development of an improved method for enhancing the nutritional value of cassava peels and other waste products.