Authentication of acacia honey using fluorescence spectroscopy

The potential of multiple fluorescence spectroscopy detection methods for the authentication of Robinia pseudoacacia L. honey (acacia honey) was evaluated. Fluorescence intensity (excitation wavelength: 280 nm), three-dimensional fluorescence spectra (excitation wavelengths: 200–460 nm; emission wavelengths: 260–560 nm), and fluorescence lifetime were recorded respectively to distinguish acacia honey (n = 160 samples harvested from eight regions of Shandong province in North China), concentrated acacia honey, and syrups. The fluorescence intensities, three-dimensional fluorescence spectra, and fluorescence lifetime of acacia honey, concentrated acacia honey, and syrups showed significant difference. Acacia honey samples had a higher fluorescence intensity and peak values as well as shorter fluorescence lifetime. The combination of the three fluorescence spectroscopy detection methods could easily distinguish acacia honey, concentrated acacia honey and syrups, and multiple fluorescence parameters gave advantage to distinguish adulteration of acacia honey, which represents a reliable, rapid, non-destructive, and low-cost method for authenticating acacia honey.