Antioxidant capacity, anthocyanins and total phenolics in purple-and red-fleshed potato (Solanum tuberosum L.) genotypes

Purple- and red-fleshed potatoes (Solanum tuberosum L.) were evaluated for their total anthocyanin (ACY), total phenolic (PHEN), and antioxidant capacity. The ACY and PHEN compounds were distributed throughout the tubers; however, a higher concentration was found at the stem-end than the bud-end. Although ACY and PHEN concentrations in potato peel were 0.9-to 1.6-fold higher than in potato flesh, overall contribution of the peel to ACY and PHEN contents of a potato slice was ∼20%. These observations differ from the widespread idea that phytonutrients are mostly accumulated in the peel of tubers. The ACY and PHEN contents of different purple- and red-fleshed potato genotypes ranged from 11 to 174 mg cyanidin-3-glucoside/100 g fresh weight and from 76 to 181 mg chlorogenic acid/100 g fresh weight, respectively, and were genotype and location dependent. High positive correlations between antioxidant capacity and ACY and PHEN suggest that these compounds are mainly responsible for the antioxidant capacity. These results provide useful and important information for potato breeders and researchers in order to increase the antioxidant capacity and functional value of purple- and red-fleshed potatoes for the food and nutraceutical industries.