Compositional Study on Rice Bran Oil after Lipase‐Catalyzed Glycerolysis and Solvent Fractionations

Abstract

Rice bran oil (RBO) was modified through lipase-catalyzed glycerolysis. After 48 h reaction, the reactant (RBO-G, solved in hexane) containing 0.14 mg/mL of MAG, 0.19 mg/mL of DAG, and 0.93 mg/mL of TAG was obtained. Extending the reaction to 72 h resulted in 0.37 mg/mL of DAG with concomitant reduction in TAG (0.68 mg/mL). Two solvent fractionation methods, independent and sequential fractionation, were performed with acetone and hexane at 0, -8, -14, or -35 degrees C. The fraction with most unsaturated fatty acids (Sigma UFA) was liquid fraction from independent fractionation at -35 degrees C (-35 In) from hexane, showing 88.3%Sigma UFA content. Nevertheless, when yield (wt%) was considered, the highest amount of UFA was obtained from 0 In (liquid fraction from independent fractionation at 0 degrees C) with hexane, resulting in 82.3%Sigma UFA with 97.9 wt% recovery. Normal-phase HPLC was conducted for the compositional study of RBO-G. Overall, solid fractions from sequential fractionation at 0 degrees C (0 SeSo) and independent fractionation at -35 degrees C (-35 InSo) with hexane contained the high concentration of total MAG and DAG, ranging from 0.94 to 1.35 (mg/mL).