Determination of 5-Hydroxymethylfurfural Content in Marketed Honey: A Modified RP-HPLC Method

Honey is a nutritive sugar alternative, well-accepted over decades due to its natural source, and a global populace drive toward natural and healthier lifestyle options. Its quality assessment includes 5-hydroxymethylfurfural (5-HMF) content, which measures freshness, but has been linked to cancer. The ability to test for this neo-formed contaminant, 5-HMF, should therefore not be compromised, even in a resource-constrained setting. In this study, a modified reversed-phase HPLC method for the assay of 5-HMF levels in honey has been developed. A nonpolar C-18 column of dimension 3.0 × 150 mm; 2.7 μm was the stationary phase of choice, while a combination of 10:90% v/v of methanol and distilled water, with 1% formic acid, was employed as the mobile phase. Detection was by diode array at a wavelength of 295 nm, using an injection volume of 1 μL. At a flow rate of 0.5 mL/min, the total runtime of the method was 8 min, with the average retention time for 5-HMF recorded at 3.87 ± 0.05 min. Validation of the method was conducted using International Council for Harmonisation guidelines, over the range of 1.25-30.0 μg/mL. It was further employed to quantify 5-HMF in 20 honey samples on the Ghanaian market with varying origin, extraction source and production state, using methanol as the dissolution solvent to ensure stability of the target compound throughout the analysis. 5-HMF levels assayed in the honey samples ranged from 0.8176 ± 0.182 to 81.1619 ± 2.1169 mg/kg of honey. At the time of analysis, 5-HMF contents of all samples except one were within the acceptable limit of ≤ 80 mg/kg of honey, set by the International Honey Commission. The 5-HMF levels quantified in market samples approved by Ghana's Food and Drugs Authority were within the acceptable limit. The developed method is comparatively cheaper and can be successfully used to analyse 5-HMF in honey samples.