A Critical Exploration of the Total Flavonoid Content Assay for Honey

Abstract

This study critically investigates the aluminium chloride–based colorimetric determination of the total flavonoid content (TFC) of honey. Following a comprehensive review of the recent literature reporting the use of the assay in the determination of TFC in honey, 10 honeys of different botanical origins were investigated using the colorimetric method alongside an artificial honey that was used as a control. Using spiking experiments, this study demonstrates that the flavonoid concentrations commonly found in honey are too low for a direct measurement and thus some of the TFC data reported in the literature might more likely be a reflection of the honey’s inherent colour rather than a product of the coordination complex formed specifically between flavonoids and Al3+ ions. This paper highlights the importance of correct blanking and suggests alternative approaches to the traditional TFC assay for honey to ensure analysis results that are truly reflective of honey’s TFC.