The growing interest in the substitution of synthetic food antioxidants by natural antioxidants and in the health implications of antioxidants as nutraceuticals has fostered research on vegetable sources and the screening of raw materials for identifying antioxidants. Plant and plant products have been used as a source of medicine for a long time. Among the more important constituents of edible plant products, low molecular weight antioxidants are the most important species. It is known that consumption of fruits and vegetables is essential for normal health of human beings. The aim of the present work was to evaluate the total antioxidant activity of selected natural food materials by an in vitro method involving the measurement of oxidation of linoleic acid by fluorimetry. Among the food materials chosen for the present study, pomegranate peel gave the maximum antioxidant activity due to the presence of its high polyphenolic content. At a concentration of 60 ppm, pomegranate peel powder reduced lipid peroxidation by 65% in an in vitro assay.