UV-Spectrophotometric Determination of Glucose, Sucrose and Fructose in Pomegranate Seeds

After adding bromine water to the sample solution obtained by dehydration of pomegranate seed with HCl, reductive glucose was oxidized and separated from sucrose and fructose. Due to the in-solubility of sucrose in ethanol, sucrose was separated from fructose by adding ethanol. Based on these facts, a method of UV-spectrophotometry for the direct determination of glucose, sucrose and fructose in pomegranate seeds was proposed. Linear relationships between values of absorbance measured at the absorption maximum of 285 nm and mass concentration of glucose, sucrose and fructose were kept in the range of within 30 mg·L-1. The proposed method was used in the determination of glucose , sucrose and fructose in a sample of pomegranate seeds, giving values of 0.203 9, 0.188 6, 0.373 1 mg·g-1 respectively. Values of RSD′s (n=6) were found less than 1.0%, and values of recovery obtained by standard addition method were in the range of 99.4%-100.1%.