In vitro evaluation tools of the antioxidant capacity

Oxidative degradation of lipids leads to quality deterioration of foods and cosmetics and has received increasing attention as a causative or associative factor in a variety of pathological conditions. A current very promising way to counteract lipid oxidation is to use vegetable antioxidants for nutritional, therapeutic or food quality preservation purpose. A major challenge is to develop analytical tools to assess the real antioxidant power of these molecules. In this way, many in vitro tests are now available, which monitor generally the inhibitory effect of antioxidant on the oxidative degradation of lipid or lipid-like substrate under natural or artificial oxidizing conditions. Overall, this measurement necessitates focusing either on the oxidizable substrate loss, or on the formation of oxidation products. To perform the first strategy, fluorophores such as cis-parinaric acid, BODIPY, and phospholipidic derivatives of fluorescein are often used, whereas the second employs usually linoleic acid, its methyl ester or natural lipids. After a brief recall of antioxidation mechanisms, this review presents a panorama of the available in vitro methodologies and of the last advances in this field. A comparative study between methods will be also discussed in terms of advantages and drawbacks.