Electrochemical methods as a tool for determining the antioxidant capacity of food and beverages: A review

- Antioxidant capacity is an important property in the development of functional foods.
- Electrochemical techniques applied to food and beverages were examined and discussed.
- Electrochemical techniques exhibit good correlation with conventional methods.
- Electrochemical assays are quick, simple, and demand little sample preparation.
- Electrochemical techniques can be applied using simply a potentiostat.

The growing interest in functional foods had led to the use of analytical techniques to quantify some properties, among which is the antioxidant capacity (AC). In order to identify and quantify this capacity, some techniques are used, based on synthetic radicals capture; and they are monitored by UV-vis spectrophotometry. Electrochemical techniques are emerging as alternatives, given some of the disadvantages faced by spectrophotometric methods such as the use of expensive reagent not environmentally friendly, undefined reaction time, long sample pretreatment, and low precision and sensitivity. This review focuses on the four most commonly used electrochemical techniques (cyclic voltammetry, differential pulse voltammetry, square wave voltammetry and chronoamperometry). Some of the applications to determine AC in foods and beverages are presented, as well as the correlation between both spectrophotometric and electrochemical techniques that have been reported.