Two-Step Neutralization Process for Extraction and Purification of Gamma- Oryzanol from Crude Rice Bran Oil

Riantong Singanusong,Thu Thuy Dang Nguyen,Sudarat Jiamyangyuen,Xuebing Xu,Wang Yong

The extraction and purification of γ-oryzanol from crude rice bran oil was achieved by a two-step neutralization process. First, some free fatty acid (3%) was removed. Second, was performed by mixing miscella with NaOH to transfer γ-oryzanol into soapstock which was dissolved in methanol and adjusted pH. It was then crystallized and bleached by washing with methanol and petroleum ether. The crystalized powder was purified by soaking in acidic methanol. Finally, γ-oryzanol powder was obtained by washing with distilled water and drying. The loss of γ-oryzanol compositions during each step was determined by HPLC. Under optimal conditions, the total of four main ferulates in crude RBO was 13,602.83 ppm, reduced to 7,887.29 ppm after the first neutralization, increased to 10,047.24ppm after the second, and was 4,750.89 ppm after purification. The -oryzanol powder remained at 34.93% of the total four main ferulates. The antioxidant activities of γ-oryzanol powder obtained from crude RBO (3.14 mg/g TE for ABTS and 1.42 mg/g TE for DPPH) were not strong due mainly to its low purity. Therefore, further improvement is recommended.

Volume 11 | 08-Special Issue

Pages: 1239-1251