Enzyme hydrolysis of cassava peels: treatment by amylolytic and cellulolytic enzymes

Abstract

Cassava peels provide a cheap non-food biomass waste that can be hydrolyzed to simple sugars as a useful feedstock. Unlike most crop wastes, they have high starch content as well as lignocellulose. In this study, an enzymatic treatment of cassava peels by various concentrations of amylase and glucoamylase is considered. Steam explosion pre-treatments reduced rate and yield of hydrolysis. Milled peels suspended at 10% w/v yielded a maximum reducing sugar of 0.41 g (as glucose) per gram of peels. HPLC analysis showed that levels of soluble oligosaccharides remained low throughout. A pretreatment with amylase at 95 °C slightly increased rates although final yield was the same. Additional treatment with cellulolytic enzymes increases the total hydrolysis yield to 0.61 g (as glucose) per gram of peels representing 91% of the carbohydrate in cassava peels.