Authentication of honey through chemometric methods based on FTIR spectroscopy and physicochemical parameters

This study describes the use of infrared spectroscopy and physicochemical parameters combined with chemometric tools to unveil adulteration of honey by glucose (G), fructose (F) and sucrose (S). 39 samples of Algerian honey in different geographical locations and 108 adulterated samples of honey with different percentages of sugars (5 to 50%) was carried out. Our analysis revealed nuanced distinctions in honey quality, the pure honey samples exhibited the following characteristics ranges: a water content (15.2–24%), an electrical conductivity (0.670–0.358 mS/cm), a pH (3.90–2.97), a Free Acidity (24.58–10 meq/kg). In the region 4000–400 cm^− 1, spectral data of pure honey and adulterated samples were recorded. The combination of spectra measurement with multivariate analyses resulted in the visualization of honey grouping and classification based on their functional group. The bands at 1800–650 cm^− 1 spectral region were selected for successful discrimination of clusters. The Principal Component Analysis (PCA), Discriminant Factor Analysis (DFA) and Hierarchical Cluster Analysis (HCA) are used to propose an effective detection approach. The results revealed a very promising discrimination process. The PC1-PC2 plane account 76.32% and 98.23% for physicochemical parameters and infrared spectroscopy analysis respectively. These two components PC1-PC2 plane could be sufficient for distinguish authentic honey. Overall, the infrared spectroscopy analysis and physicochemical parameters clearly reveal the presence of three distinct classes of pure honey, adulterated honey, and sugars.