Abstract: Combination of 1H nuclear magnetic resonance (1H NMR) spectroscopy and orthogonal partial least squares (OPLS) was successfully employed to detect rape honey adulteration with high fructose syrups. Three hundred and three authentic and 180 adulterated honey samples were analyzed. Glucose, sucrose and 13 minor components in honey samples were detected and identified from their 1H NMR spectra. The OPLS model based on NMR data was applied to detect adulteration in honey falsified by intentional addition of different concentrations of high fructose syrups. A distinct discrimination between authentic and adulterated honey samples was achieved in OPLS score plot. Overall classification rates of training set and testing set were 98.40% and 98.24%, respectively. Hence, 1H NMR spectroscopy coupled with OPLS offered a rapid and accurate tool for honey adulteration detection. The method avoided the disadvantage of monocomponent analysis and provided a potential standard for quality control of honey.

Key words: honey, nuclear magnetic resonance (NMR), orthogonal partial least squares (OPLS), adulteration