Anthocyanin and antioxidant activity of snacks with coloured potato

•Antioxidant activity and phenolics during coloured potato snacks processing were studied.•Significant influence of potato variety on obtained flour and snacks features was stated.•Snacks with Blue Congo flour marked out the highest antioxidant activity.•The most attractive colour and expansion characterised snacks with Herbie 26 flour. Coloured-fleshed potatoes of four varieties were used as raw material for coloured flour and fried snack production. The effects of thermal processes traditionally used in dried potato processing and in snack pellet manufacturing on anthocyanin profiles, total polyphenols and antioxidant properties of obtained half- and ready products were studied. There was a significant influence of potato variety on the experimental flour and snack properties. Flours with the highest antioxidant activities were obtained from Salad Blue and Herbie 26 potatoes; however, the flour prepared from the Blue Congo exhibited a much higher total polyphenol and anthocyanin content. Snacks produced with coloured flour had 2–3times higher antioxidant activities, 40% higher contents of polyphenols, attractive colour and better expansion compared to control samples. The lowest losses of anthocyanins during snack processing were in snacks with flour from the purple-fleshed Blue Congo and red-fleshed Herbie 26.