Characterization of filtered honey by electrophoresis of enzyme fractions

According to both the European Council's Honey Directive 2001/110/EC and the present Codex Aliminerius Honey Standard, filtration of honey is permitted. After this filtration process, the microscopic determination of the botanical and geographical origin of honeys is no longer possible since all the pollen has been removed. In many honey countries, there is a considerable difference in the price of honey depending on the botanical and geographical origin. There is the risk of fraud if expensive unfiltered honey is mixed with cheap filtered honey. In this research project, a method was developed that allows the detection of mixtures of filtered and unfiltered honey. Comparative tests showed that enzyme activities, mainly sucrase, were influenced by this process. The protein content did not decrease. Sucrase was isolated by gel chromatography and analysed by gel electrophoresis. One of the two dominating protein bands with 40 kDa and 65 kDa decreased significantly after filtration, which led to a shift in the natural ratio between them. The quantitative densitometric analysis of these two protein bands allows the detection of 15% added filtered honey.