SWEETPOTATO AS FOOD MATERIAL WITH PHYSIOLOGICAL FUNCTIONS

Sweetpotato (Ipomoea batatas (L.) Lam.) is one of the most important upland crops in the central and southern Japan. Several varieties contain in their storage roots high amounts of various vitamins, minerals, and protein than other vegetables. Despite its agronomic and nutritional advantages, consumption of sweetpotato has declined in recent decades. To circumvent this problem, interest has been focused on the development of new uses. Therefore, further understanding of the physiological functions of sweetpotato is considered to be one of the important factors for developing new uses. Functional foods, which offer the additional nutritional or health benefits to daily diet, became more popular in Japan. We have been investigating the physiological functions of sweetpotato, especially concerned with their diseases. Our recent study has indicated that sweetpotato contains functional components such as anthocyanins, polyphenols, dietary fiber, etc. which are available for protection of our health. We have started investigating the new utilization of the top and processing wastes in connection with the effective use of sweetpotato. It has become apparent that the leaves have the interesting physiological functions and the contents of the concerned components are high. In the future it is necessary to develop new technology for using the top and processing waste economically and effectively.