Separation and Purification of Ferulic Acid from Crude Rice Bran Oil
| Autor: | Wei-kai Lin, 林威凱 |
|---|---|
| Rok vydání: | 2011 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 99 Separation and Purification of Ferulic Acid from Crude Rice Bran Oil Student: Wei-Kai Lin Advisors: Dr. Shih-Ming Lai Institute of Chemical and Materials Engineering National Yunlin University of Science & Technology ABSTRACT Ferulic acid (FA) has many important applications in the field of medicine such as antioxidant activity, cholesterol-lowering activity, prevention against thrombosis and atherosclerosis, antimicrobial and anti-inflammatory activity, and anticancer effect. However, FA is found in very low abundance in rice bran (＜0.5% w/w). It exists as the form of ??oryzanol in crude rice bran oil (CRBO). The sequential steps including extraction, concentration, alkali hydrolysis reaction, separation and purification are needed for the production of high purity FA from CRBO. The objective of this study is to develop an efficient and easy-to-scale-up technique for the isolation and purification of FA from CRBO with high purity (＞90%) and high recovery (＞70%). In the step of extraction of CRBO from rice bran, the CRBO was prepared using an extractor with hot-plate heating and solvent refluxing operated under an optimal extraction condition (using 700 ml of hexane for 1 hr per 200 g rice bran). The extraction yield was 8~11% and the purity of ??oryzanol in the CRBO was about 1.7%. In the step of concentration of ??oryzanol in the CRBO, ??oryzanol was concentrated by a frontal chromatographic process using a preparative stainless silica gel column and hexane/ethyl acetate as the mobile phase, nearly all ??oryzanol (recovery yield ~100%) was collected in the third fraction (100% ethyl acetate), the purity of ??oryzanol reached about 12.61 % (concentration ratio= 7.29). In the step of NaOH hydrolysis reaction, under the optimal hydrolysis conditions: NaOH concentration of 3 M, temperature of 100℃, and time of 6hr, the yield of FA from 20 ml of the above ??oryzanol concentrated solution (about 29.7mg ??oryzanol) was about 9.39 mg. In the step of separation and purification, FA was purified by the method of adsorption and desorption using XAD-4 adsorbents. First, when operated in the batch mode, the adsorption results show that the adsorption ratio of FA reached about 97% at the conditions of feed solution in 2:8 (v/v) ethanol/water ratio and adsorption time of 10 min. The step-gradient desorption results show that most of FA was collected as the concentrated product at the fractions desorbed by 40% and 60% ethanol. Summing up the two collected fractions, the purity and recovery yield of FA were about 39.21% and 82.64%, respectively. Then, when operated in the column chromatographic mode, the adsorption results show that the loss of FA was only 0.5~2.0%. The step-gradient desorption results show that most of FA was collected as the concentrated product at the fractions desorbed by 40% and 60% ethanol. Summing up the two collected fractions, the recovery of FA reached 81%~93% and the purity of FA in the concentrated product reached 73.4~90.9%. Also, the recovery yields of concentrates and FA during the whole adsorption-desorption cycle reached +3%~+6% and +7%~+12%, respectively, which proved that both the masses of concentrates and FA were fairly conserved. Keywords: γ-oryzanol, ferulic acid, NaOH hydrolysis, XAD-4 adsorbents, separation and purification. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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