초임계 이산화탄소를 이용한 미강유 생리활성물질 농축

The aim of the present study was to examine the effects of different pressure and temperature combinations on the concentrations of tocols homologues, policosanol, phytosterol, and γ-oryzanol in crude rice bran oil (RBO) using supercritical carbon dioxide (SC-CO₂). To effectively separate oily substances from bioactive substances, fatty acid ethyl esterification was performed by sulfuric acid or the lipase catalytic method. In sulfuric acid esterification, γ-tocotrienol content was decreased by ca. 50%, whereas in lipase esterification, γ-tocotrienol content was not decreased. Therefore, lipase catalytic esterification was performed for the fatty acid alkyl esterification of RBO. The fractional extraction of RBO ethyl esters was performed using SC-CO₂ in the condition of 9.62 Mpa, 10.34 MPa, or 11.03 MPa and 45°C, 50°C, or 55°C. During the fractionation of RBO using SC-CO₂, a little tocols content was extracted with fatty acid ethyl esters, but policosanol and phytosterol were not extracted. Especially, there is a high correlation (R²=0.9306) between the density of CO₂ and tocols contents extracted to the fractions. The concentration rates of tocols and phytosterol were the highest in the condition of 55°C and 9.62 MPa. Therefore, the lower CO₂ density applied, the more efficient the concentrations of tocols and phytosterol were in this study.