Below is a glossary of terms used on this website and within the honey industry:
Methyglyoxal is an indicator of the activity in Manuka honey. Methyglyoxal is a very popular test for those honey producers focusing on the production of Manuka honey. If you are an AMHA member the level of Methyglyoxal can be converted into UMF® providing you a more accurate form of UMF® testing.
Hill Laboratories have developed a test for DHA which is understood to be a precursor for Methyglyoxal (MGO), an indicator of activity in honey. DHA has the potential to more accurately predict the future MGO content level in fresh honey.
Non-Peroxide Activity (NPA)
NPA is an indicator of the activity in Manuka honey and Hill Laboratories uses a chemical analysis method and GC-MS instrumentation to give reliable, accurate results every time. This is a completely different method to the inhibition assay used by other labs and one we have developed specifically to meet the needs of the honey industry in New Zealand.
Definition of HMF (HydroxyMethylFurfuraldehyde)
- Can be used as an indicator of heat and storage changes in honey or adulteration through addition of the chemical marker Methylglyoxal.
- HMF is formed by the breakdown of fructose in the presence of an acid.
3. Heat increases the speed of this reaction.
- The increase in speed is exponential with increasing heat.
- HMF occurs naturally in most honeys and usually increases with the age and heat treatment of honey.
- HMF's occurrence and accumulation in honey is variable depending on honey type.
- HMF is used as an indicator of heating or storage at elevated temperatures, it was first used (as early as 1908) as an indicator of the adulteration of honey with invert syrups (syrups of glucose and fructose). Cane sugar (sucrose) is "inverted" by heating with a food acid, and this process creates HMF. However it was quickly realized that heated natural honey also had higher levels of HMF and therefore the interest switched from being an indicator of adulteration, to that of an indicator of heating and storage changes. It should be noted however that high levels of HMF (greater than 100 mg/kg) can still be an indicator of adulteration with inverted sugars.
Please note that HMF is not a harmful substance in levels found in food. Many sugar type products (e.g. Jams, Golden Syrup, Molasses etc.) have levels of HMF that are 10-100 times that of honey. Many food items sweetened with high fructose corn syrups, e.g. carbonated soft drinks, can have levels of HMF between 100 and 1,000 mg/kg.
Fresh natural honey can have varying levels of HMF. Normally this is below 1 mg/kg but levels soon start to rise with ambient temperatures above 20°C. It should be noted that temperatures in the beehive can rise to over 40°C during summer months (when the main honey crop is in progress). It is usual for HMF to be below 10 mg/kg in fresh extracted honey. Levels higher than this may indicate excessive heating during the extraction process.
Many countries impose maximum levels for HMF. 40 mg/kg is the maximum level permissible in the EU for table honey. Please click on this link to see the Codex alimentarius Standard for Honey s HMF:
Codex Alimentarius standard for honey 12 1981
1.3 HYDROXYMETHYLFURFURAL CONTENT
The hydroxymethylfurfural content of honey after processing and/or blending shall not be more than 40 mg/kg. However, in the case of honey of declared origin from countries or regions with tropical ambient temperatures, and blends of these honeys, the HMF content shall not be more than 80 mg/kg."