Evaluation of Flour and Starch Qualities from Three Cassava Varieties for Ethanol Production Using a Novoenzyme and a Strain of Dried Saccharomyces cerevisiae (Yeast)

Flours and starches were processed from three cassava varieties namely TMS 98/0505, TMS 419 and NR 8082. The flours and starches were fermented employing Termamyl Type L Novoenzyme (an alpha amylase), glucoamylase from A.niger and dried form of Saccharomyces yeast. The flours and starches were analysed for moisture/dry matter, fibre, amylose and amylopectin contents. Slurries obtained were analysed for glucose contents, pH, total titratable acidity (TTA) and temperature during 72hrs of fermentation. The ethanol yield of the flours and starches were determined. Significant differences (P<0.05) were found among the cassava flours/starches with respect to moisture/dry matter, fibre, amylose and amylopectin contents. The ethanol yield of the flours and starches tended to be dependent on their amylose contents. Correlation between amylose and ethanol yield were 96.20% (flour) and 86.39% (starch). The yields of ethanol from filtrates of slurries obtained from fermented cassava starch samples were higher than that of the flour samples. Ethanol yields from starch of TMS 98/0505, TMS 419 and NR 8082 were 20.49%, 18.98% and 18.21%, respectively. Those of flour samples were 14.01%, 14.04% and 12.56%, respectively. The glucose contents and the pH of the fermenting slurries of the flours and starches decreased as fermentation progressed, whereas their TTA and temperatures generally increased. Ethanol yields from starch of TMS 98/0505 were the highest when compared with the other varieties used. The study recommends cassava variety TMS 98/0505 in ethanol production.