It is very difficult to verify, by testing honey, whether bees have been fed with C3-derived sugar syrups during the foraging season. Sugar-feeding is not permitted unless over winter to keep the bees alive.
In this study (open access), the researchers set out to show the potential for discrimination of sugar-fed hives using the non-exchangeable hydrogen isotope ratios on ethanol derived from honey, measured using mass spectrometry (ethanol isotope ratios are the same discriminator that underpin the proprietary SNIF-NMR databases that have been accepted for many years for fruit juice authenticity testing and have also been applied to honey)
To generate reference samples, 36 genetically similar bee colonies, at a single geographical location and time point, were subject to different controlled sugar feeding regimes. Four different sugar syrup types were used to represent distinct adulteration scenarios: fructose and glucose syrups derived from C4 plants, invert sugar derived from C3 plants (sugar beet), and sucrose syrup of unknown botanical origin. Controls were in place to stop the colonies cross-feeding.
The authors report that Ethanol δDn values for adulterated samples differed significantly from controls, enabling clear discrimination. This discrimination could form the basis of a potential classification database.
