Palynological and physicochemical characteristics of three unifloral honey types from central Argentina

Abstract

The characteristics of 59 unifloral honeys of Condalia microphylla Cav. ("piquillín"), Centaurea solstitialis L. ("yellow starthistle") and Prosopis spp., from La Pampa, Argentina, were studied. Pollen features (abundance and frequency of pollen types) and some physicochemical parameters (colour, electrical conductivity, free acidity, glucose content, glucose: water ratio, moisture and pH) were determined. Two different but related sets of calculations were done: the first involved single-factor variance analysis, while the second set involved two multivariate methods, principal component analysis and cluster analysis. Variance and multivariate analysis allowed differentiation of the three honey types according to their physicochemical properties. The variables that best explained this differentiation were pH, electrical conductivity, colour, glucose content and the glucose:water ratio. Pollen analysis showed that the pollen frequency traditionally used (> 45%) for a botanical origin assignment in honey was not valid for the unifloral honeys studied. Therefore, pollen analysis should be combined with the above physicochemical analysis order to obtain a successful classification of these unifloral honeys.