Electrochemical Methods to Evaluate the Antioxidant Activity and Capacity of Foods: A Review

Abstract

Antioxidants are an important class of food additives playing the fundamental role of retarding oxidation reactions in food. Although their functional role is well‐established, less clear is their mechanism of action. Electrochemical methods based on cyclic, differential pulse, square wave voltammetry and coulometry allow direct and rapid screening of antioxidant activity. Their main advantages are sensitivity, rapidity, simplicity and the capacity to directly measure the number of electrons transferred by an antioxidant offer advantage over conventional spectrophotometric assays. This review aims to summarize the most recent efforts towards the use of electrochemical methods to evaluate the antioxidant activity of foods.

Analytical Methods for Lipid Oxidation and Antioxidant Capacity in Food Systems

“…The electrochemical methods show similar results to DPPH, FRAP, and ABTS radical scavenging activities; therefore, the results' accuracy is high [107]. The electrochemical methods are widely used in plant-based products [107,108] and less applied in animal-based products.…”

“…In addition, some antioxidants, such as polyphenols, present in food can produce a passivating film that can reduce the conductivity of the electrodes used [106]. The electrochemical methods show similar results to DPPH, FRAP, and ABTS radical scavenging activities; therefore, the results' accuracy is high [107]. The electrochemical methods are widely used in plant-based products [107,108] and less applied in animal-based products.…”

Analytical Capabilities of Coulometric Sensor Systems in the Antioxidants Analysis

“…Reactions of AO with free radicals based on the electron transfer allow the application of the electroanalytical methods for their determination. High sensitivity, the rapidity of the procedure and relatively low costs, in addition to possibility of miniaturization make electroanalytical methods very attractive tools for the antioxidant analysis [7,15,[21][22][23][24][25] and an alternative to chromatography in screening application. Moreover, these methods can be combined with the detection in different types of liquid chromatography and capillary electrophoresis.…”

“…The reactivity of AO is shown in two types of processes. The first group of approaches is based on the AO oxidation at the electrode surface under conditions of voltammetry [7,21,25], chronoamperometry [26][27][28][29][30][31][32][33] or chronocoulometry [34,35]. The majority of these methods include the application of chemically modified electrodes providing high sensitivity and improving the selectivity of the target AO response.…”

“…The second group of electrochemical methods is focused on the reactions of AO in the solution with the oxidants. This type of interaction can be realized via the reaction with the redox probe introduced into the solution with further potentiometric detection [21,36]. Another method for the reaction is interaction with the oxidant that is electrochemically generated on the electrode surface under constant-current or constant-potential coulometry conditions [7,[37][38][39].…”