Determination of the sugar content in fruit flavoured drinks by HPLC

Abstract

Ten common fruit flavored drinks were randomly selected and purchased from the Jos metropolis, Plateau  State, Nigeria. Fruit flavoured drinks classified as soft drinks form part of a modern diet in many  communities especially for children. These drinks are available as concentrates or in processed form and they are generally considered as a decent swap for whole fruit. However, the fruit flavoured drinks only bear a passing   relationship to the real fruit and have high sugar content. Fehling's and Barfoed's tests  were conducted to  determine the presence of the principal sugars, fructose, glucose and sucrose in the  drinks qualitatively. High performance liquid chromatographic analysis was used to quantitate the  fructose, glucose and sucrose  content using hyperclone amino-bonded carbohydrate column (BDS C18 130 A, 150 x 4.6 mm) and acetonitrile: water (70:30, pH 6.8) mobile phase system at a flow rate of 0.4 ml/min. 10 µl volumes of each sample were injected and detection was by UV at 190 nm. The results of the analysis showed that the three sugars;  fructose, glucose and sucrose were present in 7 out of 10 fruit flavoured drinks at variable concentrations  ranging from 0.2 mg/l to 2046.99 mg/l. The remaining 3 fruit flavoured drinks indicated the presence of glucose and sucrose only. The sugar content of some of the drinks calls for caution in children's diet especially with the rise in obesity and dental erosion in tooth enamel associated with sugar sweetened beverages or drinks.

Keywords: HPLC; Fruit drinks, Carbohydrate; Sugars