Relationship between Acid Invertase Activity and Hexose Content in Sweet Potato Storage Roots

To elucidate the factors affecting the varietal differences in the hexose content in raw storage roots of sweet potato, relationships between the free sugar contents and the activities of acid and neutral invertases were investigated. There was a highly significant relationship between hexose contents and acid invertase activities when the cultivar Georgia Jet was excluded. The cultivar Georgia Jet showed a peculiar pattern of free sugar composition and invertase activities and was considered to have a different biochemical basis from the others. Although not all cultivars showed a strong relationship between hexose content and acid invertase activity, it was concluded that the acid invertase activity in sweet potato roots played an important role in the varietal differences in their hexose content. Keywords: Ipomoea batatas; glucose; fructose; sucrose; free sugar