Domestic cooking methods affect the phytochemical composition and antioxidant activity of purple fleshed potatoes.
The effects of domestic cooking methods (boiling, baking, steaming, microwaving, frying, and stir frying) and a new cooking method (air frying) on the composition of phytochemicals (phenolics, anthocyanins, and carotenoids) and the antioxidant activity in purple fleshed potatoes were investigated. Compared with raw potatoes, reductions of 23.59 90.42% 7.09 72.44% 7.45 83.15% and 20.15 76.16% in the vitamin C, total phenolic, anthocyanin and carotenoid contents, respectively, was observed after cooking. Decreases of 7.88% 21.55% 22.48, 6.31% and 61.38% in DPPH radical scavenging activity was also observed after boiling, steaming, baking, microwaving and stir frying, respectively, whereas an increase of 30.52% was noted after air frying. A correlation analysis revealed that the antioxidant activity was in accordance with the total phenolic content and that this activity showed the lowest correlation with the vitamin C content. Among all of the cooking methods investigated in this study, stir frying retained only slight levels of the phytochemicals and antioxidant activity observed in raw potatoes, whereas steaming and microwaving were able to retain most of the health promoting compounds found in raw potatoes and may thus be suitable methods for cooking potatoes.
Food chemistry