EFFECT OF DRYING METHODS ON BETA-CAROTENE CONTENT, PROXIMATE COMPOSITION AND FUNCTIONAL PROPERTIES OF SWEET POATATO (Ipomoea batatas L.) FLOUR

Abstract

Sweet potato are excellent sources of beta carotene, vitamins, minerals and fibers, but gradually deteriorates unless utilized. This study investigated effect of drying methods on beta-carotene content, proximate composition and functional properties of sweet potato (Ipomoea batatas L.) flour. Three different flour samples of White fleshed sweet potatoes tuber were processed using three different methods; Sun drying, Infrared oven drying and Hot air-oven drying, coded as sample A, B and C, respectively. The proximate composition, functional properties and beta-carotene contents of the flour samples were determined. It was observed that the beta carotene contents were 13.6, 14.0 and 14.3 mg/100g for hot-air oven, Infrared-oven and sun dried samples respectively. Sundried sample had the highest protein, fats and mineral contents. Compared to other drying methods, Sun-dried sample had the lowest bulk density (0.57 g/ml), water absorption capacity (106.50%) and dispersibility (50.0%). The infrared dried samples had the highest oil absorption capacity (104.0%), water absorption capacity (126.0%), loose density (0.52 g/ml) and dispersibility (62.50%). The hot-air oven dried sample has the least amount of oil absorption capacity (98.00%) and highest bulk density (0.63%). Different drying methods, especially sun drying that happened to be the best among the three methods in terms of nutritional and functional characteristics with minimal changes, can be used to produce sweet potato flours and prevent post-harvest losses, providing opportunities, improving nutritional status and well-being of the populace.