title: Concentrations of tocols and γ-oryzanol compounds in rice bran oil obtained by fractional extraction with supercritical carbon dioxide.
abstract: Rice bran oil (RBO) is a good source of several commercially important bioactive phytochemicals, such as tocols (i.e. tocopherols and tocotrienols) and ferulic esters of sterols (i.e. γ-oryzanol). The aims of the present study were to examine the effects of different pressure and temperature combinations on the fractional extraction of RBO using supercritical carbon dioxide (SC-CO2) and to assess the levels of tocols homologues and γ-oryzanol components in the resulting oil fractions. Fractional extraction of rice bran oil was performed using SC-CO2 at either 27.6 or 41.4 MPa and either 40 or 60°C. The effects of the four different pressure and temperature combinations on the levels of seven tocols homologues (α-, β-, γ- and δ-tocopherol and α-, γ- and δ-tocotrienol) and the four major components of γ-oryzanol in the resulting oil fractions were investigated. Superior extraction efficiency was obtained using the higher pressure of 41.4 MPa. The tocols (particularly α-tocopherol and α-tocotrienol) were recovered early in the extraction process, while the γ-oryzanol compounds were obtained in the later stages. With regard to SC-CO2 extraction, tocols are more soluble than γ-oryzanol components, α-tocopherol is the most soluble of the tocols and the four γ-oryzanol components all have similar solubilities. Valuable data on solubilities of tocols homologues in SC-CO2 were provided from present study.
authors.affiliation: Department of Food and Nutrition, Korea University.
authors.forename: Sung Won
authors.initials: SW
authors.lastname: Yoon
authors.forename: Young-Gil
authors.initials: YG
authors.lastname: Pyo
authors.forename: Junsoo
authors.initials: J
authors.lastname: Lee
authors.forename: Jeom-Sig
authors.initials: JS
authors.lastname: Lee
authors.forename: Byung Hee
authors.initials: BH
authors.lastname: Kim
authors.forename: In-Hwan
authors.initials: IH
authors.lastname: Kim
mesh_terms: D002245:Carbon Dioxide; D005591:Chemical Fractionation / Q000379:methods*; D010666:Phenylpropionates / Q000032:analysis* / Q000302:isolation & purification; D010938:Plant Oils / Q000737:chemistry*; D011312:Pressure; D000073879:Rice Bran Oil; D012995:Solubility; D013696:Temperature; D024505:Tocopherols / Q000032:analysis* / Q000302:isolation & purification; D024508:Tocotrienols / Q000032:analysis* / Q000302:isolation & purification
chemical_list: D010666:Phenylpropionates; D010938:Plant Oils; D024508:Tocotrienols; D002245:Carbon Dioxide; D000073879:Rice Bran Oil; D024505:Tocopherols; C013172:gamma-oryzanol