Palynological, physicochemical, biochemical and aroma fingerprints of two rare honey types

Abstract

Obtained directly from beekeepers in Portugal and Greece, some rare honey samples were subjected to melissopalynological, physicochemical (°Brix, moisture, pH, electrical conductivity, free acidity, total dissolved solids, salinity, liquid resistivity, specific weight, CIELAB colour parameters, Pfund, and colour intensity), biochemical (diastase activity, vitamin C, antioxidant activity, and total phenolic content), and volatile compounds analyses. Results showed that honey samples from Portugal were dominated by pollen grains of Anarrhinum bellidifolium (L.), whereas those from Greece were honeydew of not specific type, possessing a diverse pollen spectrum and few honeydew elements. The implementation of one-way analysis of variance showed significant differences (p < 0.05) among the two honey types in the majority of physicochemical, biochemical, and to a lesser extent in the volatile compounds. These were 34 in total, belonging to alcohols, aldehydes, benzene derivatives, esters, hydrocarbons, ketones, sulfur compounds, and terpenoids. Application of correlation, regression, and stepwise linear discriminant analyses indicated some potential fitting among the investigated parameters, and classified perfectly honey samples according to botanical origin based on electrical conductivity, salinity, 2-methylbutanal, and alpha-pinene, providing a rapid tool for the classification of less common honey types.