ABSTRACT
Solvent extraction methods are widely used for extracting antioxidant in foods and other sources. In this study, Traditional Solvent Extraction (TSE) and Microwave-Assisted Solvent Extraction (MASE) were utilized to determine the content of antioxidants in corn germ, wheat bran and wheat germ. Corn germ, wheat bran and wheat germ all contain different levels of antioxidants; TSE and MASE were utilized to determine the content of antioxidants in these three samples. TSE was performed at 60 ¨¬C employing three solvents, acetone, hexane and methanol. MASE was performed using the solvent methanol at four different temperatures, 60, 80, 100 and 120 ¨¬C. DPPH (2,2-Diphenyl-1-picrylhydrazyl) Assay was used to determine antioxidant capacity. For all samples, the most antioxidant capacity extracted using the TSE was achieved using methanol as the solvent, results ranged from 0.42-4.69 nmol Trolox/g. Using acetone and hexane as solvents for TSE yielded much lower antioxidant capacities. The MASE demonstrated consistent results compared with the TSE using methanol. In regard to wheat bran and corn germ, the capacity for antioxidants and phenolics content improved with each increase in temperature. Wheat germ yielded 3.36-3.88 nmol/g for the DPPH assay and 1248-1575 ¥ìg catechin equivalents /g for phenolics assay establishing wheat germ as containing the most antioxidant contents of the three samples. Corn germ and wheat bran displayed antioxidant capacities on a much smaller scale. The sample of corn germ¡¯s antioxidant capacity had a range of 0.90-1.19 nmol/g and 539-730 ¥ìg catechin equivalents /g, and wheat bran¡¯s antioxidant capacity and phenolics ranged from 0.39-0.72 nmol/g and 318.2-489.5 ¥ìg catechin equivalents /g. Both extraction methods were found reliable for determining the antioxidant contents of grains when methanol was employed.
| Identifer | oai:union.ndltd.org:LSU/oai:etd.lsu.edu:etd-11152006-162056 |
| Date | 16 November 2006 |
| Creators | Oufnac, David Swenson |
| Contributors | Zhimin Xu, Cristina Mirela Sabliov, Witoon Prinyawiwatkul |
| Publisher | LSU |
| Source Sets | Louisiana State University |
| Language | English |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.lsu.edu/docs/available/etd-11152006-162056/ |
| Rights | unrestricted, I hereby certify that, if appropriate, I have obtained and attached herein a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to LSU or its agents the non-exclusive license to archive and make accessible, under the conditions specified below and in appropriate University policies, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report. |
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