Multidimensional Comparative Analysis of Bioactive Phenolic Compounds of Honeys of Various Origin.

Michał Gośliński,Artur Szwengiel,Dariusz Nowak

doi:10.3390/antiox10040530

Abstract

Honey is a natural product which owes its health benefits to its numerous bioactive compounds. The composition of honey is highly diverse and depends on the type of honey and its origin. Antioxidant capacity arises mainly from the total content of polyphenols and their composition. The aim of this study was to perform a multidimensional comparative analysis of phenolic compounds of honeys of various origins. Honeydew, buckwheat, manuka, Malaysian and goldenrod honeys had the highest antioxidant capacity (above 400 mg Trolox equivalents kg−1). These honeys were also characterized by the highest total polyphenol content (about 2500 mg gallic acid equivalents (GAE) kg−1) and the highest total flavonoid content (1400–1800 mg catechin equivalents (CAE) kg−1). Other honeys had much lower antioxidant properties. A multidimensional analysis of the profiles of phenolic compounds showed that honeys constitute a non-homogeneous data set and manuka honey was in contrast to other samples. Principal component analysis (PCA) (based on 18 phenolic compounds) distinguished honeys into five groups. Manuka, Malaysian and honeydew honeys created their own separate groups and the location of other honeys was variable. Ultra-high-performance liquid chromatography (UHPLC) analysis demonstrated that profiles of polyphenols in honeys were highly varied. Caffeic acid, datiscetin and rhamnetin were characteristic compounds for manuka honey. Quercetin, kaempferol and apigenin were present in all honeys except Malaysian honey. The antioxidant properties and the profiles of bioactive phenolic compounds of honeys were miscellaneous. The richest sources of polyphenols were local buckwheat and honeydew honeys, alongside exotic manuka and Malaysian honeys. These honeys could provide valuable ingredients to the human diet, helping to prevent diseases.

Highlights

Honey has been used by people for ages; it was used in antiquity, owing to its sweetening and healthful properties [1]
Together with manuka honeys, had the highest levels of total polyphenols and the highest antioxidant capacity. This resulted from the presence of flavonoids and phenolic acids
The Fast Blue BB (FBBB) method yielded lower values of total polyphenols than the Folin–Ciocalteu assay did, which is not concordant with the results of previous studies conducted on juices

Summary

Introduction

Honey has been used by people for ages; it was used in antiquity, owing to its sweetening and healthful properties [1]. The consumption of honey varies worldwide, ranging from ca. 3 kg/person/year in the USA and ca. 0.9 kg in the EU, with the highest consumption in Greece (3.5 kg), Austria (2.5 kg) and Germany (2 kg). Despite the stable honey supply in Poland, consumption is not high The average price of multifloral honey at the site of production in the EU was 6.46€/100 kg, ranging from 19.25€ in Ireland to 2.25€ in Romania (5.81€ in Poland) [2]. In the last few years exotic honeys have become more popular, e.g., manuka and Malaysian honeys. These are available at health food stores, their prices are very high These are available at health food stores, their prices are very high (ca. 60€/500 g)

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Conclusion