Fluorescence Spectroscopy as Method for Quality Control of Honey

The present work aims in exploring the possibilities of fluorescent spectroscopy for quality control of honey, particularly to distinguish types of honey and to distinguish the natural honey from that with artificial additives - sweeteners.

24 samples of the most often encountered sorts of honey in Bulgaria distributed in 7 groups have been studied. The samples have been excited with light-emitting diodes (LEDs) emitting in the interval from 375 to 450 nm. Fluorescence spectra of all investigated honey samples have a pеаk at l = 490 nm, and for some honey samples with iso sweet an additional one at l = 505 nm. The ratio I425/I375 of the peak intensities of fluorescence spectra can be used for differentiation between natural honeys (from 1.07 to 3.35) and honey with sweeteners and honeydew About (greater than 4).

The first derivatives of the fluorescence spectra of the blossom honeys and honeydew show two peaks at about 422 nm and 480 nm. However, the first derivatives for samples with sweeteners have many different maxima and smaller amplitudes in the variations but the most clearly expressed are those around 393 nm, 480 nm and 533 nm for iso sweet and 493 nm and 479 nm for glucose additions.

The obtained results show that the investigation of fluorescence spectra opens the possibility for distinguishing honey samples with added artificial sweeteners from natural ones except for dew honey.