Use of Refractive Index to Monitor Changes in Sugar Content of Stored Sweetpotatoes

Abstract

The sugar content of five sweetpotato [Ipomoea batatas (L.) Lam.] cultivars (`Centennial', `Cordner', `Georgia Red', `Jewel', and `Sweet Red') was measured by high-performance liquid chromatography (HPLC) and compared to the sugar content of the cellular sap measured by refractive index (RI). The HPLC and RI sugar contents were measured at harvest, after curing, and during storage. Changes in the sugar content, as determined by the RI, were found to be linearly related to changes in the sugar content of cell sap and tissue, as measured by HPLC, indicating that this method can be used to monitor changes in postharvest total sugar content.