Phenolic-focused untargeted ion mobility LC-MS metabolomics reveals season-associated chemical signatures in Scottish honey.

Abstract

Honey authenticity is compromised by mislabelled origin, blending, and product modification, undermining traceability and consumer trust. To address this, we developed a phenolic-focused, untargeted ultra-high-performance liquid chromatography-ion mobility-quadrupole time-of-flight mass spectrometry (UHPLC-IM-QTOF-MS) workflow for profiling Scottish honeys using a low-solvent extraction approach and collision cross section-supported annotation (CCS-SA). Thirty-nine samples, including Scottish heather, spring, and summer honeys together with market-relevant comparators, were analysed to investigate compositional variation linked to origin, season, and product type. The workflow produced a robust, quality-controlled feature set with strong dilution linearity, while integration of accurate mass, retention time, MS/MS, and CCS increased confidence in marker annotation. Paired within-apiary comparison provided robust evidence that spring and summer honeys carry distinct season-associated chemical signatures, and heather honey emerged as a chemically distinct class. Exploratory analyses also indicated differences between Scottish and non-Scottish honeys and compositional shifts associated with blending and infusion. Because several comparator groups were small and unbalanced, these findings are considered preliminary. Overall, the workflow provides a robust platform for characterising seasonal variation and discovering candidate authenticity markers in Scottish honey.