A cascading biorefinery strategy using deep eutectic solvents (DES) was developed for protein extraction from chickpea biomass and subsequent bioethanol production from the residual lignocellulosic material. Protein was first extracted using DES, after which the remaining biomass was further pretreated with a choline chloride:oxalic acid:glycerol (ChCl:OA:G, 1:1:2) system to enhance enzymatic hydrolysis. Pretreatment parameters were optimized using Response Surface Methodology (RSM), and the optimal conditions were identified as 6% solid loading, 122 oC, and 200 min. Under this optimal condition, the reducing sugar concentration reached 14.56 mg/mL. Fermentation of the hydrolysate using Saccharomyces cerevisiae resulted in an ethanol concentration of 5.92 g/L. The results showed that DES pretreatment significantly increased sugar and ethanol concentrations due to improved structural disruption and enzyme accessibility. This study demonstrates the potential of DES as a sustainable pretreatment solvent for integrated food and bioenergy production within a circular economy framework.
Kunmanee et al. (Thu,) studied this question.