Preliminary study of hydroxymethylfurfural (HMF) presence in syrup to feed bees in Belgium

In 2009-2010 in Belgium, abnormal losses of colonies of bees were observed. Later analyses showed that some of these colonies had been fed during winter with syrup of inverted beet sugar which presented a high concentration of hydroxymethylfurfural (HMF). Several studies confirmed a toxic effect of the HMF on the health of the bee. At the moment, the absence of toxicological data of reference does not allow to establish a limit of definitive action susceptible to stop the problem. Preliminary study on HMF in syrup to feed bees has been realised in order to point out HMF formation. We have compared several home-made syrups and commercial syrup often used by beekeepers in Belgium. Several measures have been realised on syrups storage at three different temperatures: pH, sugars composition, and HMF content. The results show that commercial syrup and home-made syrup of water and saccharose were majority composed of fructose and glucose, had acid pH around 3.5 and therefore presented the most important HMF content for the three heat treatments. These results highlighted the importance to standardize the production of syrup for beekeepers but mainly for commercial producers that use directly fructose and glucose in their mixture.