Classification of Brazilian honeys by physical and chemical analytical methods and low field nuclear magnetic resonance (LF 1H NMR)

•LF 1H NMR can be used to classification of honeys.•The 1H NMR indicated the relaxation times were influenced by the differences in botanical origins in honeys.•Correlations were found between the 1H NMR parameters and physicochemical properties.

This study evaluated the possibility of differentiating the botanical origin of honeys using Low Field Nuclear Magnetic Resonance (LF 1H NMR). Eighty samples of honey from 8 different botanical sources (eucalyptus, “assa-lipto”, oranges, Barbados cherry, cashew tree, “assa-peixe”, “cipó-uva” and polyfloral) were analyzed. A close correlation (p < 0.01) was established between the LF 1H NMR analysis and physical and chemical measurements, including water content, water activity, pH and color. Bi-exponential fitting of the transverse relaxation (T2) data revealed two water populations in all samples, T21 and T22, corresponding to relaxation times of 0.6-1.8 ms and 2.3-5.4 ms respectively. The observed differences in the relaxation times suggest that these were influenced by the differences in botanical origins. Good linear correlations were observed between the T2 and T21 parameters and the physical and chemical data. This study demonstrated that LF 1H NMR can be a viable technique for use in classifying honeys by their botanical origin.