Rapid Electrochemical Method for the Evaluation of the Antioxidant Power of Some Lipophilic Food Extracts
In this paper, a novel electrochemical method to evaluate the antioxidant power of lipophilic compounds present in vegetables, such as carotenoids, chlorophylls, tocopherols, and capsaicin, is reported. The method is based on a flow injection system with an electrochemical detector equipped with a g...
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Published in | Journal of agricultural and food chemistry Vol. 49; no. 11; pp. 5136 - 5141 |
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Main Authors | , , , |
Format | Journal Article |
Language | English |
Published |
Washington, DC
American Chemical Society
01.11.2001
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Subjects | |
Online Access | Get full text |
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Summary: | In this paper, a novel electrochemical method to evaluate the antioxidant power of lipophilic compounds present in vegetables, such as carotenoids, chlorophylls, tocopherols, and capsaicin, is reported. The method is based on a flow injection system with an electrochemical detector equipped with a glassy carbon working electrode operating amperometrically at a potential of + 0.5 V (vs Ag/AgCl). The proposed method is selective for lipophilic compounds having antioxidant power. When applied to pure compounds, the order of antioxidant power resulted as follows: lycopene > β-carotene > zeaxanthin > α-carotene > β-cryptoxanthin > lutein > α-tocopherol > capsaicin > chlorophyll a > chlorophyll b > astaxanthin > canthaxanthin. Results obtained on five vegetable and two fruit extracts were compared to those obtained by the 2,2‘-azinobis(3-ethylbenz-thiazoline-6-sulfonic) acid (ABTS) radical cation decolorization assay, one of the most used methods to evaluate the total antioxidant capacity of foods. A good correlation between the two methods was found, except for spinach, because of the different antioxidant powers assigned by the two methods to chlorophylls. In conclusion, results suggest that the proposed electrochemical method can be successfully employed for the direct, rapid, and reliable monitoring of the antioxidant power of lipophilic food extracts. Keywords: Antioxidant power; carotenoids; chlorophylls; capsaicin; electrochemical method; amperometric detection |
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Bibliography: | istex:B7585B5C22667B8E6EFC07EB349765EB60C04A80 ark:/67375/TPS-82K38DHF-1 ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 0021-8561 1520-5118 |
DOI: | 10.1021/jf010731y |