Detection of honey adulteration of high fructose corn syrup by Low Field Nuclear Magnetic Resonance (LF 1H NMR)

Abstract

The effect of honey adulteration by high fructose corn syrup in different concentrations from 0% (pure honey) to 100% (pure high fructose corn syrup) was investigated using Low Field Nuclear Magnetic Resonance spectroscopy (LF 1H NMR) and physicochemical analytical methods. The LF 1H NMR data were analyzed by bi-exponential fitting and compared with physicochemical data. The physicochemical parameters demonstrated that water content, water activity, pH and color differed significantly in honey samples adulterated with different concentrations of high fructose corn syrup. These differences were also observed by transverse relaxation (T2). Bi-exponential fitting of T2 resulted in the observation of two water populations in all samples, T21 and T22, with relaxation times in the range of 1.26–1.60ms and 3.33–7.38ms, respectively. Relaxation times increased with higher percentages of high fructose syrup in adulterated honey. Linear correlations were observed between the T2, T21 and T22 parameters and physicochemical data, suggesting that LF 1H NMR can be used to discriminate pure blossom honey from honey adulterated with high fructose corn syrup.