Manuka honey authentication by a compact atmospheric solids analysis probe mass spectrometer

Manuka honey is a high-value and commonly adulterated food commodity that is produced by Apis mellifera bees from the nectar of the bush Leptospermum scoparium found exclusively in New Zealand and some parts of Australia. In this study, a rapid method using a compact atmospheric solid analysis probe (ASAP) mass spectrometer (MS) and chemometric modelling was used for the authentication of Manuka honey. Class separation was observed for Manuka honey of different production batches, brands, and grades, whereas no class separation was observed for Manuka honey of the same production batch. A one-class model training set of a production batch of honey was built (R-2 = 0.845; Q(2) = 0.686). Model validation with a prediction set of Manuka honey consisting of samples of the same production batch not used in the model, different production batches, brands, and grades gave and a perfect classifier (AUC = 1) for the receiver operator characteristic (ROC) indicating 100 % correct classification of class samples and outliers. Additionally, validation of the model against adulterated Manuka honey gave an AUC = 0.96 for the ROC. The results in this study indicate that compositional differences between production batches of Manuka honey could be used as unique chemical fingerprints for Manuka honey authentication for the purpose of brand protection and fraud detection.