Antioxidant activity, chemical and nutritional properties of raw and processed purple-fleshed sweet potato (Ipomoea batatas Lam.)

Purple-fleshed sweet potato (Ipomoea batatas Lam.) has been reported to contain vital nutrients and bioactive compounds. This study evaluates the antioxidant activity, chemical composition, and nutritional value of raw and processed purple-fleshed sweet potato products. The antioxidant activity of the raw purple-fleshed sweet potato (PSP) significantly increased after drying and decreased when the resulting flour was substituted in the products. However, substituted products had higher antioxidant activity than the non-substituted ones. The chemical properties of raw PSP mostly decreased when processed into flour and when it was used in the products. Raw PSP and the flour are good sources of energy, iron, and zinc and the candy is a good source of energy while muffin and bread are promising sources of energy, protein, and iron. Hence, purple-fleshed sweet potato could be a promising raw material for calorie-rich specialty food for children and adults which could also be sources of antioxidants.