Abstract
Contents of ?-carotene and ?-tocopherol in storage roots of sweetpotato cultivars newly developed for processing purposes were examined. These two compounds were simultaneously determined by high performance liquid chromatography (HPLC) using an ODS column, an isocratic methanol mobile phase, and both a UV-visible and a spectrofluorometric detector. Under normal cultivation conditions without mulching, Kyushu 122 had the highest content of ? -carotene (147 mg kg-1 on a fresh weight basis) among the orange-fleshed cultivars tested, and Tanegashi-mamurasaki had the highest content of ?-tocopherol (16.5 mg kg-1 on a fresh weight basis) among the purple-fleshed cultivars. The ?-tocopherol content of the purple-fleshed cultivars on a fresh weight basis was higher than that of the orange-fleshed ones, while Koganesengan, a yellow-fleshed cultivar, was the richest in ?-tocopherol content of all the cultivars tested. A similar trend was observed in cultivars grown under vinyl mulching and heavy fertilizer dressing.
