Characterization of artisanal honeys from Madrid (Central Spain) on the basis of their melissopalynological, physicochemical and volatile composition data

Forty-six artisanal honey samples, from different places of Madrid province (Central Spain), were characterized on the basis of their melissopalynological, physico-chemical and volatile composition data. Results were submitted to principal component analysis and stepwise discriminant analysis in order to evaluate the existence of data patterns and the possibility of differentiation of Madrid honey samples according to their botanical source (honeydew, nectar) and geographical collection place (mountain, plain). Colour, electrical conductivity, acidity, ash content and pH were the physicochemical parameters with higher discrimination power in the differentiation of nectar and honeydew honeys while, among the volatile components, concentrations of borneol, 1-(2-furanyl)-ethanone and 3-hydroxy-2-butanone were the most discriminant variables. In the differentiation of honey samples from mountain and plain zones, 2,3-butanediol and 1-(2-furanyl)-ethanone were the most significant volatiles, while physicochemical data were not useful for distinguishing between collection places. The honeydew percentage in a honey sample (HD%) was estimated from physicochemical measures and also from volatile concentrations; 2,3-butanediol, 3-hydroxy-2-butanone, 1-hydroxy-2-propanone and 1-(2-furanyl)-ethanone were found to be related to HD%.