Process Optimisation of Enzymatic Saccharification of Soaking Assisted and Thermal Pretreated Cassava Peels Waste for Bioethanol Production

摘要

In this study, enzymatic saccharification of soaking assisted and thermal pretreated cassava peels waste was investigated using the response surface methodology. Optimization studies on fermentable sugar yield for bioethanol production were carried out. The effect of substrate loading (% w/v), α-amylase concentration (U/g), amyloglucosidase concentration (U/ mL) and cellulase concentration (% v/w) were investigated within the range of 10-30, 90-150, 30-100 and 0-3 respectively. The model gave a coefficient of determination (R~2) of 0.89 and the optimum process conditions established were substrate loading of 10.16% w/v, α-amylase concentration of 125.3 U/g, amyloglucosidase concentration of 74.06 U/mL and 2.34% v/w cellulase. Experimental validation gave 0.58 g/g fermentable sugar yield and a saccharification efficiency of 78.66%. FTIR analysis revealed the changes in the functional group which further corroborated the effectiveness of these enzymatic conditions. Subsequent fermentation of the hydrolysate gave an ethanol yield of 0.53 g/g using Saccharomyces cerevisiae. The study therefore substantiates the potential of cassava peels waste for bioethanol production.