NMR-based metabolomic approach to differentiate organic and conventional Italian honey

Abstract

Honey represents a well appreciated food product endowed with several beneficial properties. In these last decades organic agriculture highly impacted social and political thought involving also honey production. To the best of our knowledge, no studies are present in literature focusing the differentiation of organic and conventional honeys. The present study demonstrated the capability of the combined use of 1H NMR spectroscopy and chemometrics, to address this important issue. Specifically Italian polyflower, chestnut and acacia honeys have been differentiated on the basis of the water soluble compounds, by taking the advantage of the application of Orthogonal Signal Correction (OSC) filters on 1H NMR data leading to highlight molecules responsible for sample differentiation. Succinate and acetate resulted the common compounds characterizing all conventional honey samples along with other different metabolites specific of each botanical origins, while a higher content of kynurate was observed for organic chestnut honeys. Moreover the HMF content was quantified by 1H NMR to evaluate sample freshness, thus confirming the content largely below the acceptance limit of 40 mg kg−1 for all samples.