Direct measurement of the total antioxidant capacity of foods: the 'QUENCHER' approach

Extraction-dependent methods were used to evaluate the antioxidant capacity up to now. The extraction conditions applied before the measurement represent a source of variations among laboratories and in some cases are not reliable. The direct procedure described in this paper skips all time-consuming solvent extraction and hydrolysis steps. A review of the solubility and localization of food antioxidant compounds was provided as base to understand the advantage of the direct procedure with respect to the extraction protocols present in the literature. The application of the procedure to some case-studies was also illustrated.