Polyphenol profile of honeydew and polyfloral honey from northern part of Montenegro

Abstract

Introduction: Honey is a high energetic sweet food composed, among other components, of bioactive compounds that attribute therapeutic properties of this product. As antioxidants, polyphenols are recognized as the major constituents in honey responsible for its health promoting properties. Bees produce a floral honey from the collected nectar of flowers, and honeydew honey from collected excrement of insects or plants. Considering that Montenegro is a country with traditional beekeeping, this is the first time to publish the results of its honeydew and polyfloral honey samples. Experimental: Analyzed honey samples, honeydew and polyfloral, were collected from three locations in norther part of Montenegro, Berane, Bijelo Polje and Pljevlja. Polyphenol profile of six honey samples was determinated by identifying polyphenols on UHPLC-LTQ OrbiTrap MS, and by their quantifications on UHPLC-DAD MS/MS. Results: Of the 32 identified polyphenol compounds, 24 were present in all samples. Appearing the other eight polyphenol compounds has no constant diversity between the samples. The similarity between them was confirmed by their quantifications. The highest proportion in total polyphenols has a quercetin with a mean value of 3.82 mg/kg, followed by p-hydrohybenzoic acid and p-coumaric acid. Slightly higher content of chrysin, pinocembrin, p-protocatechuic and vanillic acid can be noticed. The quantifications of the target compounds include 33 polyphenols, and only 16 of them were previously identified. This indicates the occurrence of certain dissimilarities between two used techniques, which are the consequences of similar spectra of certain polyphenols and their derivatives. Conclusion: This is the detailed study of polyphenols in Montenegrin honeys. Based on the obtained results, it can be seen that the investigated honey samples are very rich in polyphenols, with no significant differences between honeydew and polyfloral samples. Considering small areas that cover these three regions of norther part of Montenegro, it can be assumed that small diversity in plant species causes overlapping in honeybee’s pastures and similarity of samples