Buckwheat honey: screening of composition and general properties

Buckwheat honey is produced at different levels of “uniflorality” depending on the extent of the cultivated fields and on the amount of wild flora contemporarily blooming in the surrounding areas. In Italy, monofloral buckwheat honey is uncommon and it is usually found as a part of multifloral honeys. Due to increased focus on healthy foods, there is a growing interest in the production of foods made from buckwheat. Because of the lack of gluten it is particularly suitable for use by sufferers of coeliac disease. More extensive cultivation of this plant have been projected for the future and the amount of monofloral honey available on the market may consequently increase. Buckwheat honey, collected from little pink flowers by honeybees, is characterized by a dark purple color, almost black, and by a strong animal odour, malty aroma and molasses flavour. Since an exhaustive characterisation is not yet available, the principal aim of this study was to propose a preliminary but comprehensive and detailed investigation of the composition and properties of that botanical origin. Honey samples, collected from Italian and eastern European beekeepers, were evaluated by means of their pollen, physico-chemical, sensory, phenolic and volatile composition data. Volatile compounds are related to aroma and are involved in honey authentication, whereas phenolic compounds have antioxidant effects and due to buckwheat honey having a high content of these it could be promoted as nutraceutical, a food product that reportedly provides health and medical benefits. Traditional analyses enabled the distinction of samples with good purity from others more strongly influenced by honeydew which as a result could not be included in the typology. Honey volatiles, analysed by solid phase microextraction (SPME) and gas chromatography mass-spectrometry (GC/MS), showed more than 100 compounds with the 3-methylbutanoic acid as the principal. This molecule in combination with 2- and 3-methylbutanal and pheynalcetaldehyde, contribute to the typical buckwheat aroma. The HPLC chromatograms of the phenolic extracts showed p-hydroxybenzoic and p-coumaric acid as the most abundant compounds. The similar phenolic pattern and 3-methylbutanoic acid content in the aromatic profile could be treated as possible fingerprints for distinguishing buckwheat honey