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A Buyer's Guide to Manuka Honey

What You Need to Know:

 1. Definition of Non-Peroxide Activity (NPA) Manuka Honey

2. The assay number: 5+, 10+, 12+, 16+ etc

3. Brand Standards measuring and certifying NPA:  UMF, MGO, MGS

4. A buyer's guide to identifying Genuine (NPA) Manuka Honey and assessing its quality.

5. Other ‘bio-active’ properties of manuka honey and other honeys in New Zealand and around the world.

6. The health properties of Genuine Manuka Honey 


1.  Definition of Non-Peroxide Activity (NPA) Manuka Honey

 Defining ‘active manuka honey’ is a major consumer issue and it is not easily resolved: you need to understand that ‘manuka’ is not just one honey and one health functionality. And then, as an informed customer or consumer you can make your purchasing decision accordingly.

New Zealand Manuka honey is an icon of New Zealand and an icon of healthful honeys globally. The awareness of a special activity in New Zealand Manuka honey came about from the pioneering work of Professor Peter Molan MBE at the NZ Honey Research Unit at Waikato University in the late 1970’s and 1980’s. That pioneering research has continued to this day.

Professor Molan and his team identified a bioactivity in some Manuka honeys that was not based on hydrogen peroxide:

  • All honeys kill some bacteria in some circumstances, and virtually all honeys kill bacteria through making hydrogen peroxide.
  • But some Manuka honeys retain a special antibacterial activity even when their hydrogen peroxide-making ability has been neutralized.
  • It is the antibacterial activity in this original discovery that has since been found to kill drug-resistant superbugs and even be effective through layers of skin. Its also the unique activity that was used in the initial stomach ulcer research.

Professor Molan named these honeys ‘active manuka’ but because the word ‘active’ could be rightfully applied to all honeys Professor Molan worked with the NZ Manuka industry to develop the phrase ‘unique manuka activity’ and the trademark ‘UMF®’.

Some companies use the UMF trademark, one company uses the trademark MGO, and in 2009 Professor Molan agreed for his own name to be used for honeys with the “original manuka activity” under a new Brand Standard for honeys: The Molan Gold Standard. In addition some other companies use a general description and the consumer should establish if it is the “original non-peroxide activity” those companies are referring to with the words ‘active’ or ‘total activity’ if NPA-manuka is what the consumer believes he/she is paying for.


2.  The assay number: 5+, 10+, 12+, 16+ etc

  •  When Professor Molan tested the manuka honeys he used the internationally recognised method of measuring the surface area kill-zone of a sample of honey dropped onto a plate of bacteria.
  • The size of the kill-zone is compared to what phenolic acid would achieve. Phenolic acid is a common industrial antiseptic.
  • So a measure of ‘12+’ means the honey was comparable to a 12% solution of phenolic acid: this is known as the phenol assay.
  • To understand the potency of that: an industrial strength solution of phenolic acid is 4% (4+) and that will kill all bacteria but also harm skin tissue: whereas manuka honey with a 20% (20+) potency has been used to treat eye infection and if 20+ phenolic acid had been used it would have caused blindness.
  • The bioassay method used by Professor Molan was a simple laboratory test and not initially intended for a complex task such as measuring differences between honeys.
  • The method has been adapted over the years and still remains the benchmark: but it can produce a variable reading. Companies usually pack over-strength to ensure they meet the label claim.


3.Brand Standards measuring and certifying NPA:  UMF, MGO, MGS

Official Brand Standards if correctly enforced offer the consumer confidence that the honey is true to label and contains Non Peroixde Activity on which the scientific findings are based. 

All of the standards rely on a laboratory certificate assaying the Non Peroxide Activity of a sample and that the honey producer/ marketer has sampled accurately and batched the honey following a packing methodology that ensures the honey has not separated.


4. Identifying Genuine (NPA) Manuka Honey and assessing its quality.

  • High levels of NPA is one parameter - but remember that the research trials of Manuka Honey are based on samples of NPA level of 10+ or higher.  Equally, natural NPA levels of 25+  or higher are rare and improbable and probably the result of (artificial heating of the honey to boost NPA scores). NB this also raises HMF levels or combining PA and NPA values of the honey thus giving a higher activity level which doesn't correlate with the activity levels quoted in the studies.
  • Most honey is also tested for HMF, moisture content (typically 19-21% for manuka) and pollen content 
  • Pollen counts (absolute and relative counts) are often very low in genuine manuka as it produces small amounts of pollen and the nectar is more easily available to the bees. Conversely, a Kanuka, a close relative of Manuka and also a native shrub of New Zealand, produces very high amounts of pollen.
  • Some Manuka honey has low or absolutely no Non Peroxide Activity whatsoever so evidence of a test is vital.
  • Organic standards cover wider quality parameters - e.g. heating
  • Some brands set higher standards than the minimum standards required by food health and safety and trading standards bodies in country and even some organic standards. See Green Bay quality promise here:  http://www.greenbayharvest.co.uk/qualitypromise/
  • Taste - Flavour notes of Malt, caramel and damp Earth
  • Texture - thixotropic, crystalizing into large crystals
  • Colour  - golden, turning light brown in the jar after packing. Dark brown Manuka honey may have been articificially heated to increase activity.
  • Although there is increasing scrutiny and cross-checking of minimum quality across more of the supply chain, there are numerous possibilities for unscrupulous producers, packers and marketeers to evade the standards. Consumers and trade customers paying for and relying on the well documented health benefits of genuine manuka honey are advised to buy from a brand they trust absolutley for integrity of business practices and knowledge of honey and production practices. Reputable brands should be able to provide evidence in the form of source documents from impartial and professional third parties (e.g. lab reports) of quality parameters of a batch from which a given consumer unit has been packed.


 5. Other ‘bio-active’ properties of manuka honey and other honeys in New Zealand and around the world.

  • Professor Molan’s early research identified antioxidant and anti-inflammatory activities in some honeys that were separate to the original manuka antibacterial activity.
  • This is research still in progress and shows exceptional promise for consumer health values.
  • The NZ Honey Research Unit and Waikato University has identified that some New Zealand honeys have a unique preemptive iron chelating antioxidant value and others a strong free radical scavenging antioxidant value.
  • The relationship between these values and the original manuka activity is still not known for certain.
  • It is also uncertain how the original manuka activity works inside the human body. There is very good evidence to show it does have a positive effect but the science is still incomplete as to how and why.
  • For this reason, New Zealand native bush honeys and manuka honeys without the non-peroxide activity still look certain to still have special health and wellness values for their antioxidant and anti-inflammatory effect.
  • The Research Unit has prioritized research into these areas and the licence fees paid for the Molan Gold Standard goes towards this research.
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