Rapid analysis of glucose, fructose and sucrose contents of commercial soft drinks using Raman spectroscopy

The objective of this study was to quantify glucose, fructose, and sucrose in commercial soft drinks by Raman spectroscopy as a fast and low-cost technique. For the calibration, dilutions in the range of 0-12% (w/w) were prepared in water for each of glucose, fructose, and sucrose. The Raman spectrum for each dilution was obtained. Calibration models were formed and curves were plotted by using the full spectrum of Raman data. The partial least squares (PLS) regression method was used to carry out the spectroscopic data analysis. The contents of the sugars in the soft drinks were predicted depending upon the calibration models by PLS. The slope of regression values of glucose, fructose, and sucrose were 0.967, 0.992, and 1.008 and the coefficient of determination (R-2) values were 0.913, 0.998 and 0.993 for validation, respectively. A high-performance liquid chromatography (HPLC) method was used to verify the efficiency of the Raman method. The coefficient of determination values between the HPLC and the predicted values of glucose, fructose and sucrose were determined as 0.913, 0.968 and 0.910, respectively. The results of this work provide a rapid method for evaluating the quantitative analysis of glucose, fructose, and sucrose in soft drinks. (C) 2014 Elsevier Ltd. All rights reserved.