Enrichment of tocols from rice germ oil using supercritical carbon dioxide

Abstract

An efficient process was developed for enrichment of tocols from rice germ oil (RGO) using supercritical carbon dioxide (SC-CO 2). Tocols were efficiently enriched in residue by removal of fatty acid methyl ester from the esterified RGO using SC-CO 2. The enrichment of tocols was carried out at an operating pressure of 12.4-15.8MPa, an operating temperature of 40-60°C and a carbon dioxide flow rate of 5.0Lmin -1. The combination of 13.8MPa pressure and 60°C temperature was selected as the most suitable for efficient enrichment of tocols. The level of tocols (1270mg/100g) in the residue obtained at these operating conditions was six times higher than the tocols level (192mg/100g) of the starting material, namely esterified RGO. There were no significant differences in relative percentages of tocols homologues between esterified RGO and the residue obtained by SC-CO 2 extraction. © 2012 The Authors. International Journal of Food Science and Technology © 2012 Institute of Food Science and Technology.