Valorization of Cassava Peel and Pulp Through ⁶⁰Co-γ Irradiation Pretreatment for Enhanced Glucose Release and Bioethanol Production

This study investigates the impact of γ-irradiation pretreatment on cassava waste biomass (cassava peel and cassava pulp) at varying radiation doses (0, 250, 500, 750, and 1000 kGy) for enhanced bioethanol production. The pretreatment was assessed through changes in visual appearance, qualitative and quantitative glucose analysis, surface morphology, ethanol yield, and ethanol concentration. The findings demonstrated that γ-irradiation significantly altered the color and texture of cassava biomass and enhanced glucose release, particularly at doses above 500 kGy. SEM analysis revealed increased porosity and fiber disintegration, especially in cassava pulp, supporting improved enzymatic digestibility. While ethanol yields remained relatively stable across doses, ethanol concentrations increased markedly, reaching peak values at 750–1000 kGy. Cassava peel consistently produced higher ethanol concentrations, although cassava pulp showed greater sensitivity to structural disruption. These findings suggest that γ-irradiation can be a chemical-free pretreatment strategy to improve fermentable sugar recovery and ethanol titers from cassava waste. However, higher doses (750–1000 kGy) likely require considerable energy input, implying operational costs and environmental sustainability trade-offs. Therefore, future work must include techno-economic analysis and life-cycle assessment to validate the overall viability of γ-irradiation pretreatment.