Seeking of reliable markers related to Greek nectar honey geographical and botanical origin identification based on sugar profile by HPLC-RI and electro-chemical parameters using multivariate statistics

Abstract

The objective of the present work was to investigate whether the combination of sugars (fructose, glucose, sucrose, and maltose) or sugar mathematical transformations (fructose plus glucose content and fructose-to-glucose ratio) and electro-chemical parameters [liquid resistivity (LR), total dissolved solids (TDS), and salinity] of Greek nectar honeys, namely, thyme and citrus, could enhance the existence of some reliable markers of honey geographical and botanical origin identification using multivariate statistics. Sugars were determined using high-performance liquid chromatography coupled to a refractive index detector, whereas electro-chemical parameters using a lab-scaled conductivity meter. Results showed that both sugar and electro-chemical parameters varied significantly (p < 0.05) according to geographical and botanical origin of nectar honeys. Application of multivariate statistics such as exploratory factor analysis, multivariate analysis of variance, and linear discriminant analysis showed that sucrose, maltose, sum of fructose and glucose contents, LR, TDS, and salinity could be used as indices of Greek thyme honey geographical origin, whereas fructose and maltose contents along with the ratio of fructose to glucose, as markers of nectar honey botanical origin, as reflected by the satisfactory prediction rates obtained.