Sweet potatoes are effortlessly grown and high yielding food crop. However, these are considered as underutilized produce with limited incorporation into food industry. Hence the objectives of this study were to determine the nutrient composition and functional properties of twelve (12) sweet potato varieties available in Sri Lanka to study the potential to be incorporated into food production. The varieties analysed were Ama, Dhawala, Wariyapola White, Wariyapola Red, Shanthi, Hordi Malee, CARI 09, CARI 273, Ranabima, Gannoruwa White, Chithra and Makandura Purple. Determination of moisture, ash, crude protein, crude fat, dietary fiber (soluble/insoluble), carbohydrates and functional properties were by standard methods. Ash, crude fat and crude protein contents comprised less than 7% (dry matter; DM) with total carbohydrate content varying between 49-80% DM in studied sweet potatoes. Total dietary fiber comprises approximately 8.5% (DM) with the highest proportion being insoluble dietary fiber. Functional properties resulted a swelling capacity of 15-27 mL with high oil absorption capacity (120-220%), emulsion activity (42-48%) and stability (above 35%), and bulking density (0.62-0.95 g/cc) with least gelation concentration of 18-30%. The results prove the ability of the studied sweet potato flours to be incorporated in composite flour mixtures and novel food products.

Sweet potatoes are one of the major tuberous roots consumed around the world. The objective of the present study was to determine the nutritional composition, glycaemic indices and glycaemic loads of selected Sri Lankan sweet potato varieties, in order to address the inadequacy of information and the controversial findings on glycaemic indices. Nutrient composition (moisture, ash, digestible carbohydrates, dietary fiber, crude protein and fat) of boiled sweet potatoes, GI and glycaemic loads (GL) of nine varieties were determined using standard methods. Digestible carbohydrate content ranged between 29-88% on dry weight. Ash, crude protein and crude fat contents of the varieties ranged between 3.1-5.0%, 3.0-5.9% and 2.6-5.3% on dry weight basis (DW) respectively. The total dietary fiber content was above 9.5% DW in the studied varieties. Moisture content of boiled sweet potato tubers were 72-81% on fresh weight basis and both the GIs (86-119) and GLs (>20) were high. However, the GL reduced to medium or low when considering an actual edible portion for all the varieties except for two varieties. Sweet potatoes are a good source of highly available carbohydrates which elicit high GIs.