Sensitive and Selective Pathway of Total Antioxidant Capacity in Commercially Lemon, Watermelon and Mango-pineapple Cold Teas by Square Wave Adsorptive Stripping Voltammetry

Abstract

The present work describes a convenient method for the sensitive and selective pathway of total antioxidant capacity (TAC) in lemon, watermelon and mango-pineapple cold teas by square wave adsorptive stripping voltammetry (SWAdSV) that is major electroanalytical methods on a carbon paste electrode. Anodic peak current of p-coumaric acid exhibited a well oxidation peak at 780 mV was used as a standard to evaluate TAC in tea samples. In addition, the very well-resolved and reproducible anodic processes, such as accumulation time, frequency, step potential etc. were optimized for the SWAdSV method. The potential applicability of the proposed SWAdSV was illustrated in commercial teas samples. SWAdSV proved to be a faster and easier method to calculate TAC compared to other conventional methods. Furthermore, total antioxidant amounts of commercially lemon, watermelon and mango-pineapple cold teas were found in optimum condition as equivalent to a concentration of 2050 +/- 15mg/L, 705 +/- 10 mg/L and 808 +/- 14 mg/L p-coumaric acid (n=3, 95% confidence level), respectively.