The objective of the research was to determine the total polyphenol content, antioxidant activity, and colour of both the dried purple and red fleshed potatoes blanched in organic acids solutions and the potato snacks produced using those dried potatoes. The raw material studied were dried potatoes produced from tubers blanched in tartaric acid solution (purple fleshed potato varieties) or citric acid solution (red fleshed potato varieties); they constituted a semi-finished product to produce potato pellets that were, next, fried to make potato snacks. The content of polyphenols, antioxidant activity, and colour were determined in dried potatoes and potato snacks. In addition, the fat content was analyzed in the potato snacks as were their hardness, expansion index, and sensory features. It was found that blanching the flesh-coloured potatoes in organic acids solutions made it possible to save a significant amount of polyphenols in dried potatoes; however, the blanching did not inhibit changes induced by thermal processing, i.e. the so-called chemical darkening. Dried purple fleshed potatoes were beige-purple, brown-violet, or purple, and snacks made from them were beige. The dried red fleshed potatoes maintained the pink colour and the snacks made from them were beige-pink or pink. Snacks produced from coloured-fleshed potato varieties contained more polyphenols (4 ÷ 116 %) and they had a higher antioxidant activity of DPPH• (3.5 ÷ 5 times higher), ABTS•+ (2.3 ÷ 4 times higher), and FRAP (1.2 ÷ 2.5 times higher) compared to a control sample. Using the purple and red fleshed potato varieties made it possible to produce snacks that were characterized by acceptable sensory characteristics; however, because of the important role of colour in consumer acceptance, the method of producing dried potatoes from raw coloured-fleshed potato tubers should be modified.
purple and red fleshed potatoes, blanching, dried potatoes, snacks, colour, polyphenols, antioxidant activity