Optimization of DIC technology as a pretreatment stage for enzymatic saccharification of Retama raetam

Abstract In this work, we propose a new technology for the pretreatment and the conversion of Retama raetam biomass into oligosaccharides and glucose based on Instant Controlled Pressure Drop (DIC). DIC technology is a thermo-mechanical method based on short-time/high-temperature and pressure pretreatment that avoids the thermal degradation of sugars. The main objective of this work is to prove the feasibility of DIC as a pretreatment method of R. raetam biomass. Response Surface Methodology was used through a design of experiments in order to optimize the processing parameters, maximize the generation of sugars and minimize their degradation yields. The obtained results confirm that R. raetam pretreatment using DIC has a significantly positive effect on the generated monomeric sugar yields. Our experiments show that the highest hexose yields were obtained with lower pressure and water content. Moreover, these conditions minimized the degradation of sugars into ethanol conversion inhibitors. Hereby, the maximum glucose yield obtained after the enzymatic hydrolysis of the DIC treated R. raetam was 18 mg/g dry matter.