Physicochemical properties of purple sweet potato flour fortified with legumes

Abstract

The popularity of purple sweet potato continues to increase annually. Natural sweetness, attractive color, and high antioxidant were alleged as the main allurement of its products. Nevertheless, there are some lacks on the nutritional properties of purple sweet potatoes, such as low in protein and lipid. This shortcoming could lead to a serious malnutrition problem if there is no nutritional complement from another source. In this condition, fortification could serve as a strategy that addressed to improve the nutritional value of sweet potato products. As a source of protein and bioactive compounds, legumes are potential to be a carrier on the fortification process. This study was aimed to determine the physicochemical properties of sweet potato flour fortified with legumes. A completely randomized design with four fortification treatment was used, i.e. soybean, mungbean, cowpea, and without fortification as a control treatment. The results showed that among other legumes, soybean is the most effective carrier on fortification of sweet potato flours. Purple sweet potato flours that were fortified with 10% soybean have the highest nutritional properties, specifically protein (8.65%), lipid (3.02%), and amylose (32.09%). Legume fortification would also reduce the carbohydrate fraction and generated darker colors in the sweet potato flours.