Hydrophilic and Lipophilic Antioxidant Capacity in Foods: Measurement and In Vivo Implications

Abstract

The measurement of both lipophilic and hydrophilic antioxidant capacity in food is possible using the oxygen radical absorbance capacity (OItAC FL ) assay. Data from these measurements provide a measure of antioxidant capacity using specific biologically relevant free radical sources, usually the peroxyl radical, but different radical sources can be utilized in order to obtain the relative response of different dietary antioxidants to different radical sources. The effects of food processing and of genetics, harvest maturity, and environmental growing conditions on antioxidant components can be evaluated. The in vitro measure of antioxidant capacity provides information on potential for dietary antioxidants to defend against free radical damage in the gastrointestinal tract; however, information on what the in vivo response will be following consumption of the dietary antioxidants may not directly correlate. It is clear that specific phytochemical components in foods are absorbed/metabolized quite differently; thus in vivo techniques are necessary to confirm that antioxidant status will be altered as a result from consumption of the specific source of dietary antioxidants.