Integrated rice bran processing by supercritical CO2 extraction and subcritical water hydrolysis to obtain oil, fermentable sugars, and platform chemicals

Rice bran is rich in oil and constituted by a lignocellulosic structure, which is a potential raw material for its processing into several products. Therefore, the oil yield and composition of oil obtained from supercritical CO2 extraction were investigated to select a condition for using defatted rice bran for processing by subcritical water hydrolysis. The effects of temperature (230 degrees C and 260 degrees C) and solvent-to-feed mass ratio (50 and 100 g water/g defatted rice bran) on fermentable sugar yield (YFS) and hydrolysate composition were evaluated and discussed. Supercritical CO2 extraction at 40 degrees C and 20 MPa provided an oil yield of 17.19 wt% at 120 min. For defatted rice bran, the highest YFS (6.53 g sugars/100 g defatted rice bran) was obtained at 260 degrees C and 100 g water/g defatted rice bran.

Automated summary

Rice bran, rich in oil and with a lignocellulosic structure, can be used as a raw material for processing various products. This study investigated the oil yield and composition of oil obtained from supercritical CO2 extraction, aiming to find suitable conditions for processing defatted rice bran through subcritical water hydrolysis. The results showed that higher temperature and solvent-to-feed mass ratio led to a higher fermentable sugar yield.