PHYSICO-CHEMICAL PARAMETERS OF ROMANIAN RASPBERRY HONEY

Abstract

Six samples of raspberry honey collected from different regions of Romania were analysed in order to confirm that they are classified as monofloral honey. Melissopalynological analysis, alongside the determination of physico-chemical parameters - moisture, pH, free acidity, electrical conductivity, hydroxymethylfurfural (HMF) content, color, total polyphenols content, flavonoids content, DPPH radical scavenging activity - were chosen as methods of analysis that give indications regarding the botanical origin of honey.The results of the melissopalynological analysis showed that all honey samples had a percentage of Rubusidaeus pollen grains above the minimum of 45%, which was required in order to classify the samples as monofloral honey. The values determined for pH (4.01-4.31), free acidy (20.1-42.1 meq/kg) and electrical conductivity (0.36-0.52 mS/cm) confirmed that the samples were of pure raspberry honey. In the case of moisture content, one honey sample exceeded the moisture content set by Codex Alimentarius (20%). The limit set for HMF content was not exceeded by any raspberry honey sample, for which values of 6.13-26.79 mg HMF/kg were determined. Raspberry honey had high total polyphenols content (8.11-12.86 GAE/100 g), flavonoids content (25.36-41.35 mg QE/100 g) and DPPH radical scavenging activity (58.1-94.35%). These results contribute to the knowledge of the chemical compositions and physical parameters of Romanian honeys.