Sweet potato not only contains primary materials such as dietary fiber, vitamin and soluble protein, but also provides abundant secondary metabolic products which have hygienical functions, like caffeic acid and caffeoylqinic acid derivatives, and anthocyanins, carotanoids. Many studies showed that many secondary products of sweet potato have hygienical functions as quenching free radicals, antioxidation, and preventing cancer, cardiovascular disease and diabetes. Further understanding of the hygienical functions of components in sweet potato is considered to be one of the important factors for developing new uses of sweet potato.
