Potatoes, due to consumed amount, are considered as one of the major sources of antioxidant compounds in the human diet. Moreover, in recent years, there has been an increasing interest in potato varieties with coloured flesh, mainly because of their high anthocyanin content. Given that diets rich in anthocyanins and other related phenolic compounds have been associated with a reduced incidence and severity of certain kinds of cancer and heart disease, coloured potatoes could be preferred in the diet even as processed foods, such as snacks, as a natural source of antioxidants.
Compounds with antioxidant activity have capability to inactivate free radicals, which negatively influence biologically important compounds such as lipids, proteins and nucleic acids. Major antioxidant compounds in common yellow potatoes are polyphenols, ascorbic acid, carotenoids etc.
Apart from common yellow-fleshed potatoes there are many varieties with intense red, purple or blue colour only in peel or in flesh or in both. Such potatoes, grown today in relatively small areas in many countries, are available mainly through organic markets for customers targeting innovative products.
In line with published studies to Food Chemistry Journal coloured potatoes contain twice high levels of phenolic acids compared to yellow-fleshed potatoes. Moreover, coloured varieties of potatoes contain in pulp and peel plant natural pigments anthocyanins. There are also studies showing that coloured potatoes could be used as potential replacements for banned dyes due to their possible health benefits.
Specifically according to a recent research conducted by Agnieszka Nems et. al. (2015) red and purple fleshed potatoes of four varieties were used as raw material for coloured flour and fried snack production. The snacks produced with coloured flour had 2–3 times higher antioxidant activities, 40% higher contents of polyphenols, attractive colour and better expansion compared to control samples.
It is known that antioxidants naturally presented in food have health-promoting and anti-aging effects in the human body. Coloured potatoes could be used as novel sources of natural colorants and antioxidants with added value for the food industry and human health. Furthermore, they are suitable for diversification of potato dishes.