Potential of colored potatoes for producing high antioxidant snack foods

Abstract

Potatoes are one of the most important vegetables in the world in terms of consumption and overall nutritional value. This paper aims at determining potential of color fleshed potatoes for producing processed products rich in antioxidants. Antioxidants in peeled purple flesh potatoes was determined to be 332 µg Trolox equivalent per gram of dry weight (µg TE/g DW) followed by 82 µg TE/g DW in red and 79 µg TE/g DW in yellow potatoes. Purple potatoes were also high in phenolics (2914 µg Gallic acid equivalent per gram of dry weight (µg GAE/g DW)) followed by red (944 µg GAE/g DW) and yellow (941 µg GAE/g DW) potatoes. 1.671 mg per gram of dry weight anthocyanins was found in purple potatoes, compared to 0.014 mg/g DW and 0.014 mg/g DW in red and yellow potatoes, respectively. Purple potatoes were peeled, blanched and dehydrated with three different drying methods to prepare potato flakes. Preliminary results showed 100–180 % increase in total antioxidant capacity (TAC) in all the drying methods. Freeze drying increased TAC by 182 % followed by drum drying (140 %) and refractance window drying (103 %). All the selected drying methods showed a two fold increase in total phenolic content (TP). Refractance window drying increased TP by 270 % followed by drum drying (212 %) and freeze drying (207 %). However, 20–40 % losses in total anthocyanins content (TA) were observed in all the three drying methods with 41 and 45 % of losses found in drum drying and freeze drying whereas refractance window drying retained 77 % of TA. Potential of colored potatoes rich in antioxidants should provide excellent opportunities for production of nutritionally enhanced food products.