The Origin of MGO in Manuka Honey
Methylglyoxal, or MGO, is a natural organic compound and the primary antibacterial component of Manuka honey. It is formed from another compound, dihydroxyacetone (DHA), which is found in high concentrations in the nectar of the Manuka tea tree (Leptospermum scoparium). When bees collect this nectar and process it into honey, the DHA slowly converts into MGO over time as the honey matures.
This conversion process means that freshly harvested Manuka honey will have lower MGO levels and higher DHA levels. As it ages, the DHA decreases while the MGO increases, reaching peak potency after several months. This natural process is unique to Manuka honey and explains why its antibacterial properties are significantly more stable and potent than those of most other honey types, which get their antibacterial effect from hydrogen peroxide.
Why MGO Levels Are Not Consistent
Several factors contribute to the wide variation of MGO levels found in Manuka honey. The purity of the nectar source is one of the most critical determinants. Beekeepers strategically place hives in areas with a high density of Manuka bushes to ensure bees collect predominantly Manuka nectar, resulting in higher DHA and, subsequently, higher MGO content. Conversely, if bees forage on a mix of Manuka and other flowers, the resulting multifloral honey will have lower MGO concentrations.
Factors that influence MGO levels include:
- Floral Source Purity: The ratio of Manuka nectar to other floral nectars determines the initial DHA content.
- Harvest Location: Soil, climate, and environmental factors can all influence the amount of DHA in the Manuka flower nectar.
- Honey Maturity and Storage: As honey ages, the conversion of DHA to MGO occurs. Optimal temperature and storage conditions are vital for this process, as overheating can destroy the beneficial compounds.
- Honey Processing: Excessive heat used during pasteurization can also degrade MGO levels. Raw, unprocessed Manuka honey is more likely to retain its full potency.
Decoding Manuka Honey Labels: Monofloral vs. Multifloral
To help consumers understand the source and potential potency of their honey, New Zealand's Ministry for Primary Industries (MPI) has established clear definitions for monofloral and multifloral Manuka honey.
- Monofloral Manuka Honey: This honey is made predominantly from the nectar of the Manuka flower. It must meet specific chemical marker and DNA tests and typically contains higher concentrations of MGO and other beneficial compounds.
- Multifloral Manuka Honey: This honey comes from a blend of nectars, with a significant but not predominant amount coming from the Manuka bush. It still contains MGO and other bioactive compounds but generally at lower, less potent levels.
Comparison of Monofloral vs. Multifloral Manuka
| Feature | Monofloral Manuka Honey | Multifloral Manuka Honey |
|---|---|---|
| Nectar Source | Primarily Manuka flowers | Blend of Manuka and other flowers |
| MGO Concentration | Generally higher and more potent | Typically lower |
| Taste Profile | Strong, earthy, and sometimes slightly bitter | Milder, with a varied flavor profile |
| Therapeutic Potency | Higher potency, suitable for targeted wellness and medical use | Lower potency, suitable for daily use and general wellness |
| Price Point | Higher, due to stricter sourcing and potency | More affordable |
| Purity | Higher purity standards for export certification | May contain a wider array of pollen and compounds from different plants |
MGO in Other Honeys
While MGO is the signature compound of Manuka honey, it's not exclusively found in it. Other types of honey also contain methylglyoxal, but the concentration is remarkably different. Studies have shown that the levels of MGO in conventional honeys are often 100 times lower than in Manuka honey. For example, one study found MGO levels in some Italian honeys ranging from 0.4 to 24.1 mg/kg, compared to Manuka honey's range of 40 to over 800 mg/kg. This vast difference is why Manuka honey is particularly prized for its potent antibacterial effects.
Certification and Grades: Ensuring Authenticity
With the market for Manuka honey growing, certification has become crucial for consumers. Reputable brands provide clear grading labels, most commonly MGO or UMF™ (Unique Manuka Factor).
- MGO Grading: This system measures the exact concentration of methylglyoxal in milligrams per kilogram (mg/kg). An MGO 263+ rating, for example, indicates a minimum of 263mg of MGO per kilogram. This is a clear, scientifically validated measure of potency.
- UMF™ Grading: The UMF™ certification is a broader, trademarked system that also incorporates MGO levels, but includes other markers to prove authenticity and quality. A UMF™ rating assures that the honey is genuine New Zealand Manuka, unadulterated, and meets specific standards for MGO, DHA (the precursor), and Leptosperin (a Manuka-specific compound). A higher UMF™ grade directly correlates with a higher MGO concentration.
Conclusion
The short answer to the question "Does all Manuka honey have MGO?" is yes, but the more important factor is the concentration of MGO. While all genuine Manuka honey contains methylglyoxal, the level can vary significantly. This potency depends heavily on the floral source and processing method. Monofloral Manuka, sourced primarily from Manuka blossoms, contains the highest MGO levels and is often used for its superior antibacterial effects. Multifloral Manuka, while milder, still offers beneficial properties for everyday use. Consumers should always look for a certified MGO or UMF™ rating on the label to ensure they are purchasing a product with verified potency and authenticity. The level of MGO should align with your intended use, whether for daily wellness or targeted therapeutic support.
For more detailed research on the chemical properties of Manuka honey, authoritative sources like the National Institutes of Health (NIH) provide valuable studies.
