Analysis of volatile organic compounds by GC-IMS and GC-E-NOSE: A powerful approach for honey discrimination

Honey represents one of the most relevant food fraud targets, which is mainly ascribable to its economic value and its worldwide production, but also to the existing problems related to the monitoring and management of bees’ farms. To corroborate its authenticity, the assessment of the honey’s volatile fraction combined with chemometric techniques could be an innovative and powerful analytical alternative. The aim of this study was to analyze the volatile organic compounds (VOCs) from Acacia and Millefiori honey samples by using two diverse gas chromatography (GC) instruments (Heracles GCE- Nose and FlavourSpec GC-IMS), followed by chemometric processing, in order to discriminate honey according its intrinsic characteristics (i.e. botanical origin). The results showed that the two GC instruments were able to generate very similar outputs, when used under the same operating, analytical, and statistical conditions. The untargeted analysis of honeys’ volatile fraction associated with chemometric data processing led to sample clustering, thus allowing a preliminary identification of qualitative differences among honey samples. In addition, targeted GC-IMS analysis proved to successfully identify discriminating molecules to legitimize the sample classification obtained with the untargeted GC analysis, being thus useful to distinguish with greater certainty a conventional honey from an organic one.