Authentication of the botanical and geographical origin of honey by front-face fluorescence spectroscopy

Front-face fluorescence spectroscopy, directly applied on honey samples, was used for the authentication of 11 unifloral and polyfloral honey types (n = 371 samples) previously classified using traditional methods such as chemical, pollen, and sensory analysis. Excitation spectra (220-400 nm) were recorded with the emission measured at 420 nm. In addition, emission spectra were recorded between 290 and 500 nm ( excitation at 270 nm) as well as between 330 and 550 nm ( excitation at 310 nm). A total of four different spectral data sets were considered for data analysis. Chemometric evaluation of the spectra included principal component analysis and linear discriminant analysis; the error rates of the discriminant models were calculated by using Bayes' theorem. They ranged from < 0.1% ( polyfloral and chestnut honeys) to 9.9% ( fir honeydew honey) by using single spectral data sets and from < 0.1% (metcalfa honeydew, polyfloral, and chestnut honeys) to 7.5% ( lime honey) by combining two data sets. This study indicates that front-face fluorescence spectroscopy is a promising technique for the authentication of the botanical origin of honey and may also be useful for the determination of the geographical origin within the same unifloral honey type.