Cold hydrolysis of cassava pulp and its use in simultaneous saccharification and fermentation (SSF) process for ethanol fermentation.

Highlights • Ratio of α-amylase to glucoamylase is important in saccharifying cassava pulp (CP). • Cold hydrolysis at 50 °C followed by 30 °C is effective in CP saccharification. • A model was developed for predicting the performance of cold hydrolysis process. • A sequential process for bioconversion of CP to ethanol was proposed. • The proposed process yielded 27.4 g-ethanol/L, with 57.8% fermentation efficiency. Abstract The present study investigated cold hydrolysis of cassava pulp (CP) and the use of cold hydrolysis with simultaneous saccharification and fermentation (SSF) for ethanol production. Cold hydrolysis of 100 g-CP/L at 50 °C for 2 h, followed by at 30 °C for 72 h resulted in the production of 71.5 ± 1.8 g/L of reducing sugar, with a yield of 0.72 g/g-CP. A mathematical model describing the cold hydrolysis process was subsequently developed. The model proved to be applicable for other cold hydrolysis systems with satisfactory results. The sequential process of cold hydrolysis at 50 °C for 2 h, followed by SSF at 30 °C for 72 h gave 27.4 g-ethanol/L, with a productivity of 0.37 g/(L h) and a fermentation efficiency of 57.58%. Based on the results, a bioconversion process for CP to ethanol was proposed. In this process, 1 kg of ethanol could be produced from 3.65 kg of CP without any nutrient supplementation. [ABSTRACT FROM AUTHOR]