Electrochemical Biosensors for the Determination of the Antioxidant Capacity in Foods and Beverages Based on Reactive Oxygen Species

Reactive oxygen species (ROS) are very unstable molecules generated during the metabolism. They can be produced in excess, contributing to cellular dysfunctions. Antioxidants are substances that play an important role as a health-protecting factor, limiting the lesions caused by ROS. Two kinds of electrochemical biosensors based on ROS have been described to evaluate the antioxidant capacity in the food industry. The first one involves hydroxyl radicals and studies their effect on DNA alterations. The second one consists of the superoxide radicals scavenging ability, radicals being essentially generated by the xanthine/xanthine oxidase system. These sensors are commonly based on either cytochrome c or superoxide dismutase, even though recent strategies are emerging. Whatever the involved ROS, all the described biosensors possess similar advantages such as simplicity, rapidity and low cost and are successfully applied for the assessment of antioxidant properties in various foods, additives or beverages.