The impact of cooking procedures on antioxidant capacity of potatoes

Summary Recent studies have strongly supported the efficacy of diet rich in phytochemicals in reducing the risk of cardiovascular disorders, high cholesterol and cancer. Phytochemicals, such as plant polyphenols, vitamins and carotenoids, exert multiple beneficial effects due to their antioxidant properties. Being the most consumed vegetable of human daily food consumption, potato has attracted considerable interest as a potential source of dietary antioxidants. Current study includes a comparative analysis of antioxidant properties of yellow, red and blue potatoes typical for the Czech Republic, with the relation to their phenolic contents in fresh, cooked, cooked in steam, microwave-heated and fried potato samples. The objective was to find the relationship between the antioxidant capacity, total phenolics and potato variety in 12 samples of different potato cultivars. The impact of cooking procedures on antioxidant capacity of potatoes is also examined. Total antioxidant capacity in potato was determined using 2,2’-azino-bis(3-ethyl-benzothiazoline-6sulphonate) (ABTS) assay and 2,2-diphenyl-1-picrylhydrazyl (DPPH) method. The total phenolic content was evaluated according to the Folin-Ciocalteau colorimetric assay and also by selective HPLC. Both antioxidant capacities and total phenolics were expressed as chlorogenic acid equivalents. The results demonstrate that antioxidant activities of potato correlate with phenolic contents in all samples. Red and blue varieties have significantly higher values of both phenolics and antioxidant contents compared to yellow potato.