Methylglyoxol (MG) is found in a range of food products including wine, beer, roasted coffee, bread, dairy products, soy sauce and lipids (fats). But the reason we are talking about it is because it also constitutes the major part of the total antibacterial activity found in New Zealand Manuka honey. MG is thought to increases significantly in plants that are exposed to stressors such as salinity, drought and cold. Fortunately for us Manuka honey grows well under just these types of conditions. It is often found on the steep erosion prone hill country of New Zealand and under these stressful condition it produces an excess of MG which is then transferred to the honey. (2)
MG occurs within honey as a non-enzymatic reaction, which is also known as caramelisation or The Maillard reaction. This process is desirable, as it is known for creating the desirable tastes and colors of cooked foods. It is also what gives honey its golden hue. (2) MG was pinpointed as the non-peroxide activity (NPA) of Manuka honey in 2008 by two independent laboratories. It occurs over time through the natural chemical transformations of DHA (dihydroxyacetone) a naturally occurring phyto-chemical present in the nectar of the Manuka flower. This naturally occurring substance has the ability to react with DNA and RNA. Therefore theoretically it could be toxic to humans, however there has been no evidence found that it does this. Instead it appears to have a selective toxicity only for bacteria cells making it the perfect product for reducing scaring and preventing bacterial infections when used either orally or as a wound dressing. (1)
Now that MG has been identified as the component that makes Manuka honey what it is, New Zealand is experimenting with growing Manuka plantations. Farmers often have land, which is not conducive to grazing and seek other opportunities to make money with this extra space. Until recently more often than not this land was leased to companies as logging plantations.
However, a study conducted in 2016 has show that plantation Manuka grown in specific provinces can produce Manuka nectar that contains double the amount of MG than indigenous Manuka. Indicating the potential of farmers to produce high UMF honey and opening up a whole new avenue for revenue for local New Zealand Farmers. (3)
- Carter, D. A., Blair, S. E., Cokcetin, N. N., Bouzo, D., Brooks, P., Schothauer, R., & Harry, E. J. (2016). Therapeutic Manuka Honey: No Longer So Alternative. Frontiers in Microbiology, 7, 569. http://doi.org/10.3389/fmicb.2016.00569
- Adams C. J., Boult C. H., Deadman B. J., Farr J. M., Grainger M. N. C., Manley-Harris M., et al. (2008). Isolation by HPLC and characterisation of the bioactive fraction of New Zealand manuka (Leptospermum scoparium) honey. Carbohydr. Res.343 651–659. 10.1016/j.carres.2007.12.011
- Millner J. P., Hamilton G., Ritchie C., Stephens J. (2016). High UMF honey production from manuka plantations. HSC Symposium. https://www.grassland.org.nz/publications/nzgrassland_publication_2772.pdf