Physicochemical parameters prediction and authentication of different monofloral honeys based on FTIR spectra

Abstract

Samples of raspberry, mint, rape, sunflower, thyme, acacia and tilia honey were subjected to authentication using destructive (melissopalinological analysis and physicochemical parameters determination) and non-destructive (Fourier transform infrared spectroscopy – FTIR) methods. The melissopalinological analysis confirmed that all types of honey samples were authentic monofloral honey. To correlate the FTIR spectral information with the physicochemical parameters and therefore assess the usefulness of FTIR in the analysis of honey quality and authenticity, the spectral information was coupled with principal component analysis (PCA), linear discriminant analysis (LDA) and partial least square regression (PLS-R). PCA showed a clear separation can be observed for 5 groups of honey, namely: mint, rape, acacia, tilia and sunflower honeys, while thyme and raspberry honeys are mixing some samples. Moreover, the PLS-R model was found successful in predicting the physicochemical parameters of honey based on FTIR spectra. These results show that FTIR spectroscopy can be simultaneously used to confirm the authenticity of honey and also its quality and freshness.