Development of separation method for Alpha-Tocopherol and Gamma-Oryzanol extracted from rice bran oil using Three-Zone simulated moving bed process

Abstract

• The chromatographic separation method of gamma-oryzanol and alpha-tocopherol was developed. • An environmentally friendly solvent was employed for the separation. • A three-zone simulated moving bed system was designed via process simulation. • The purities of greater than 98% for both compounds were suggested at the optimal condition. • The maximum productivity was obtained at the optimal condition. Gamma-oryzanol and alpha-tocopherol are bio-active compounds that can be found in crude extract of rice bran oil. With superior properties of gamma-oryzanol such as antioxidant activities, anticancer, and antidiabetic, while alpha-tocopherol is one type of vitamin-E, they are both widely used in foods, pharmaceuticals, nutraceuticals, and cosmetic. Therefore, the isolation of these compounds from the crude extract to obtain a single component with high purity is important. In this study, the separation of gamma-oryzanol and alpha-tocopherol using chromatographic method was investigated. The type of mobile phase for C18 column was selected based on the selectivity, back pressure, and toxicity. The adsorption of mono-component was performed to determine the adsorption parameters and the mathematical model for breakthrough curves was developed. The model and the associated parameters were validated by the adsorption experiments using binary mixture. The verified model was used in the design and optimization of three-zone simulated moving bed process. The mobile phase was the mixture of ethanol and water (90 :10 V/V%). At the optimal conditions of the three-zone simulated moving bed, the purity of extract product (rich in gamma-oryzanol), the purity of raffinate product (rich in alpha-tocopherol), and the separation productivity were 99.24%, 98.69% and 29.87 g/L⋅min, respectively.