Physiochemical, nutritional and antioxidant properties of fourteen Virginia-grown sweet potato varieties

Small-scale farmers in Virginia have been forced to seek alternatives to tobacco as a consequence of economic and regulatory changes affecting the industry. Sweet potato is suggested as one of the alternatives and is well-adapted to environmental conditions of southern Virginia. A study is underway to evaluate sweet potato varieties for production in Virginia using sustainable practices, but limited information is available concerning their physicochemical, nutritional quality and antioxidant activities. The objective of this study was to characterize these properties for fourteen sweet potato varieties including white, yellow, orange and purple flesh, grown in Virginia. All the properties analyzed were found to be significantly (P < 0.05) different among the varieties. Orange flesh varieties had the highest moisture content, while their purple flesh had the lowest. The carbohydrate content ranged between 81.3 and 87.3% with starch accounting for 49.9-64.1% of total carbohydrate content. Varieties with lighter colored flesh appeared to have greater total starch content. Sucrose was the major sugar with content ranging from 4.73 to 16.5%. Total phenolic and flavonoid contents for the two purple varieties were about 2-8 folds and 3-15 folds higher than for the other varieties, respectively. Anthocyanins were only found in purple-fleshed varieties. The results of this study demonstrated that physiochemical, nutritional and antioxidant properties of sweet potatoes varied by varieties.