18E-9 |
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D. M. WEBBER, R. Horax, and N. S. Hettiarachchy. Dept. of Food Science, Univ. of Arkansas, 2650, N. Young, Fayetteville, AR 72704 Cowpeas are legumes that serve as a quality source of carbohydrates, dietary fiber, protein, vitamins, and minerals; furthermore, phenolic acids have been identified and extracted from 17 cowpea varieties by methanol solvent. However, it is previously undetermined what effect the extraction solvent type may have upon the phenolic acid content and the antioxidant capacity of cowpea extract. The objectives were to determine the com-position of three varieties of southern grown cowpeas, evaluate the effectiveness of four different solvents systems on the extraction of total phenolics, and deter-mine the antioxidant capacity of these extracts. The lipid, protein, moisture, and total starch contents of cowpea varieties Arkansas 95-104, Black Crowder, and Louisiana Purplehull were determined using AACC methods. Phenolics were extracted from cowpea flour using methanol, ethanol, 20o C water, and 60o C water. These extracts were tested for total phenolic contents and antioxidant capacity by use of Folin-Ciocaleu′ reagent and linoleic acid methyl ester model systems, respectively. Total phenolic contents of extracts ranged from 1.98 to 28.40 (mg CAE/g cowpea extract). The methanol extract from Black Crowder contained the greatest amount of phenolic acids, followed closely by ethanol extract, with total phenolic contents of 28.40 and 19.05 (mg CAE/mg extract), respectively. The two water extraction techniques, however, had the greatest extraction efficiency (extract weight/flour weight) followed by methanol solvent. The methanol and ethanol extracts from the Black Crowder showed the greatest antioxidant capacity with 69.51% and 67.49% inhibition, respectively, followed by the 60o C H2O extract from Lousinana Purplehull with 66.55% inhibition. The data suggests that the total phenolic contents in cowpeas may be linked to the antioxidant capacity of phenolic extracts. Furthermore, the antioxidant capacity and other beneficial properties of cowpeas may, with further investigation, be harnessed for nutraceutical and functional applications.
Session 18E, Nutraceutical & Functional Foods: General I
2005 IFT Annual Meeting, July 15-20 - New Orleans, Louisiana |