Optimum Conditions for Supercritical CO₂ Treatment of Rice for Sake Brewing and Changes in Structure of Rice Grain by The Treatment

Supercritical CO₂ Treatment of Rice for Sake Brewing (Part 1)

Abstract

Crude fat was readily extracted from polished rice with liquid and supercritical CO₂ at pressures of 50-250 kg/cm². The efficiency of extraction was highly dependent on the density of CO₂. For an efficient extraction the pressure and temperature of the fluid had to be controled to maintain the density over 0.8 g/cm³. A large portion of crude fat in 1 kg of rice was removed within 8-9 minutes with 375 Nl of CO₂ at the optimum condition.
Rice germ and bran adhereing to the surface of polished rice were also removed by the treatment.