Sen, Sarani and Sarkar, Priyabrata (2013) A new diagnostic tool for measuring total antioxidants in tea. Sensor Letters, 11 (2). pp. 428-435. ISSN 1546-198X

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The purpose of this research was to develop a sensory system to measure antioxidant level in tea with a view to assessing the quality of different grades of tea available in the market. We proposed an easy, reliable sensory system to quantify the total antioxidant capacity (TAC) of tea infusion. A preformed ABTS [2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonate)] radical cation (ABTS(+)) was used in the bulk electrolyte in presence of glassy carbon (GC) or platinum (Pt) working electrode. Total antioxidant present in sample was determined by amperometric response at optimum redox potential of 0.552 V dictated by cyclic voltammogram. Linear calibrations for standard antioxidants such as gallic acid, caffeic acid, ascorbic acid, catechin hydrate and chlorogenic acid were obtained in the range of 1-250 mu g/mL. Quantitative estimation of antioxidants in tea samples were expressed as gallic acid equivalent (GAE) with a detection limit of 2.34 mu g/mL. The amperometric sensor showed optimum response at pH 5.8 at around 25 degrees C. Excellent correlations were obtained with standard spectrophotometric assays. The system might be useful for quality control of various grades of tea due to its specificity, simplicity and quick response of measurement procedures. The present research gave excellent opportunity to grade tea on the basis of antioxidant levels. Similarly the system might have useful applications in determining antioxidants in other common food items such as fruit juices and other beverages.

Item Type: Article
Subjects: Microstructure and Characterization
Depositing User: Bidhan Chaudhuri
Date Deposited: 23 Sep 2013 09:32
Last Modified: 23 Sep 2013 09:32

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