Spectroscopy and chemometric-based method for sugar profiling in high-fructose syrup

High-fructose syrup (HFS) is widely used as an alternative sweetener in the food and beverage industries. Due to its high cost, it is often susceptible to adulteration with cheaper ingredients such as sucrose, making the accurate determination of fructose, glucose, and sucrose concentrations critical. This study developed a method for the simultaneous determination of these sugars in HFS using ATR-FTIR spectroscopy combined with chemometrics. Two calibration approaches were compared: (1) the STD-Cal method, which utilized a calibration set prepared from standard sugar mixtures, and (2) the HFS-Cal method, which used a calibration set derived from HFS samples. Each approach was evaluated using principal component regression (PCR), partial least squares (PLS), and support vector machine-regression (SVR). The HFS-Cal method, when combined with PCR, yielded excellent predictive accuracy with low RMSEC values (fructose: 0.014; glucose: 0.009; sucrose: 0.004) and RMSEP values (fructose: 0.071; glucose: 0.041; sucrose: 0.002), along with high coefficients of determination (R² values between 0.9200 and 0.9996). Statistical analysis using the t-test confirmed that the sugar concentrations determined by this method were consistent with those obtained from the reference method (HPLC-RID). The developed method provides a rapid and reliable alternative for the determination of fructose, glucose, and sucrose concentrations in HFS, making it suitable for routine surveillance and quality control purposes. © 2025