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Spectrophotometric quantification of ascorbic acid contents...

Summary citation from AGRICOLA, the online catalog of the National Agricultural Library (NAL)

Spectrophotometric quantification of ascorbic acid contents of fruit and vegetables using the 2,4-dinitrophenylhydrazine method.

Accurate quantification of the nutritional and antioxidant properties of raw materials is important in the diet and nutritional management. In this study, the 2,4-dinitrophenylhydrazine colorimetric method widely used for determination of ascorbic acid level in biological fluids was adapted to estimate total vitamin C content in fruits. The procedure depends on the principle of oxidation of L-ascorbic acid to dehydroascorbic acid and 2,3- diketo-gulonic acid, followed by reaction with 2,4-dinitrophenylhydrazine. After treatment with sulfuric acid, a colored product is formed which is absorbed at 520 nm. Using standard ascorbic acid at different concentrations, Beer's law was obeyed up to 2.0 mg dL-1concentration range, which resulted in the following equation of the linear calibration curve: y = 4.0827x - 0.0423, R2 = 0.9923. The most critical and decisive step in the procedure for an accurate reading is the preparation of a final clear extract of the fruit or vegetable. Analysis of vitamin C contents in selected fruit using both titrimetric and spectrophotometric methods are presented.

Journal Title: Journal of food, agriculture & environment.
Journal Volume/Issue: 2007 July-Oct., v. 5, no. 3-4
Main Author: Al-Ani, M.
Other Authors: Opara, L.U., Al-Bahri, D., Al-Rahbi, N.
Format: Article
Language: English
Subjects: ascorbic acid
fruits (food)
vitamin content
food composition
spectral analysis
new methods
Internet resource
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