ABSTRACT

This study determined the nutritional values of dried, fermented and boiled sweetpotato flour using two different species (orange flesh and white flesh) respectively. The proximate contents, minerals, antioxidant vitamins and glucose were determined using standard methods. The proximate contents revealed that carbohydrate content in the white flesh was 86.01% for fermented, 86.20% for dried and 86.15% for boiled samples as compared to 85.51% for fermented, 85.93% for dried and 85.72% for boiled samples in the orange flesh. The protein content was 3.25% for fermented, 2.98% for dried and 2.03% for boiled samples in the white flesh as compared to 3.16% for fermented, 2.88% for dried and 2.12% for boiled samples in the orange flesh. Calcium content was 301.38mg/100g for fermented, 316.87mg/100g for dried and 334.69mg/100g for boiled samples in white flesh as compared to 250.43mg/100g for fermented, 257.04mg/100g for dried and 269.16mg/100g for boiled in orange flesh. The orange dried samples had the highest values for vitamin A (2061.19mg/100g), vitamin C (13.47mg,T00g) and vitamin E (0.64mg/100g) whereas white flesh boiled had the least vitamins in vitamin A (186.42mg/100g), vitamin C (2.41mg/10g) and vitamin E (0.12mg/100g). For glucose concentration, the white flesh dried had the highest concentration (8.78%) while the orange flesh fermented had the least (3.46%). The results ofthis study show that more nutrients were available by the direct oven drying process. The fermentation process yielded lesser proximate contents, glucose and minerals such as calcium, sodium, potassium, iron and zinc compared to other methods. This study therefore suggests that direct oven drying is the best method for the preparation ofsweetpotato flour.