Optimizing enzymatic hydrolysis of cassava peels for enhanced glucose production: effects of process parameters and cellulase prehydrolysis

Abstract

Response surface methodology (RSM) was employed to optimize a two-step enzymatic process (liquefaction and saccharification) for converting cassava peels into glucose sugar. Hydrothermal treatment of the peels was employed to facilitate sugar release. A two-factor interaction model effectively characterized the relationship between enzyme dosage, temperature, and time, and their impact on glucose yield. For the liquefaction step, the maximum glucose yield achieved without cellulase prehydrolysis was 22.54 ± 1.03 mg/g-biomass at 50 °C with an α-amylase dose of 2.5% (v/w-biomass) for 40 min. With cellulase prehydrolysis, the maximum glucose yield reached 64.10 ± 0.6 mg/g-biomass at 70 °C with an α-amylase dose of 2.31% (v/w-biomass) for 80 min. In the saccharification step, the highest glucose yield obtained without cellulase prehydrolysis was 45.01 ± 1.2 mg/g-biomass at 70 °C with a glucoamylase dose of 2.5% (v/w-biomass) for 40 min. With cellulase prehydrolysis, the maximum glucose yield attained was 64.29 ± 0.8 mg/g-biomass at 70 °C with a glucoamylase dose of 2.5% (v/w-biomass) for 80 min. Cellulase prehydrolysis significantly enhances sugar yield during both liquefaction and saccharification of cassava peels. Cassava peel proves to be a promising substrate for glucose sugar production, with potential applications in the production of bioethanol and other valuable products.