Comparison of conventional and alternative technologies for the enzymatic hydrolysis of rice hulls to obtain fermentable sugars

In this work was investigated the use of alternative technologies to improve the enzymatic hydrolysis of rice hulls. The use of supercritical CO2 as co-solvent and ultrasound-assisted hydrolysis was evaluated and the results were compared with a conventional procedure. Maximum yield of fermentable sugar obtained was about 16 g kg−1 using conventional or ultrasound-assisted hydrolyzes. The yield obtained in the hydrolysis using supercritical CO2 was around 4.2 g kg−1 as co-solvent. Enzymatic hydrolysis using the conventional procedure showed to be the best manner to obtain fermentable sugar from rice hulls since the alternative technologies employed did not lead to better results.