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The amino acid composition of 53 honey samples from Spain, consisting of 39 floral, 5 honeydew, and 9 blend honeys, has been determined. Physicochemical characteristics, polyphenolic content, amino acid composition, and estimation of the radical scavenging capacity against the stable free radical DPPH of the honey samples were analyzed. The resulting data have been statistically evaluated. The results showed that pH, acidity, net absorbance, electrical conductivity, and total polyphenolic contents of the honeys showed a strong correlation with the radical scavenging capacity. The correlation between the radical scavenging capacity of honey and amino acid contents was high with 18 of the 20 amino acids detected, with correlation values higher than those obtained for polyphenolic content. These results suggest that the amino acid composition of honey is an indicator of the sample's scavenging capacity.

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Artisanal honey samples produced in Madrid province (central Spain) were characterised from their melissopalynological analysis, carbohydrate composition and physicochemical parameters. Melissopalynological analysis showed that Echium sp pollen appeared as the dominant palynomorph in most samples. It was also observed that many honey samples were natural blends from both nectar and honeydew botanical origins. Twenty-five carbohydrates (glucose, fructose, 16 disaccharides and seven trisaccharides) were detected and quantified. Discriminant analysis was used to describe the variability of compositional data, which was probably associated with the different honey sources analysed (honeydew, Echium sp and other nectar plants), which in turn was related to the physiographical conditions (plain or mountain) occurring in Madrid province.

Differentiation of nectar and honeydew honeys is difficult, not only because of the wide variability in composition and organoleptic properties among samples from the same source, but also because of the frequent existence of honeys resulting from a blend of nectar and honeydew. A mathematical expression to evaluate the relative presence of honeydew in a honey sample (HD) has been developed from relevant physicochemical properties of honey samples selected as highly representative of both honey types on the basis of their physico-chemical and melissopalynological analysis. As honey aroma depends on its volatiles composition, GC-MS analysis of the volatile fraction obtained by SPME has been carried out in order to evaluate its usefulness in honey source differentiation. Stepwise regression from multicomponent volatiles data was used for the estimation of HD and for determining which volatile compounds were related to the different honey sources.