Criteria for defining Australian Manuka Honey

Criteria for defining Australian Manuka Honey

Authors: Dr Peter Brooks, Dr Craig Davis, Dr Shona Blair and Dr Nural Cokcetin Scientific Advisory Committee to the Australian Manuka Honey Association.

The below provides a set of robust science-based criteria to identify, define and authenticate Australian Manuka honey.

What is Australian Manuka honey?

Australian Manuka honey is produced naturally by bees, from the nectar of plants of the Leptospermum genus. Australia has the largest diversity of Leptospermum plants in the world, with over 80 native species growing throughout the country in a variety of habitats from coastal dunes to high mountain peaks.

Background

Manuka honey is one of the most famous honeys in the world because of its medicinal properties. Numerous scientific studies have shown that this honey has potent antimicrobial activity. The special properties of Manuka honey were first found in New Zealand in the 1980s (Molan & Russell, 1988) and since then we have discovered many sources of active Manuka honey in Australia stemming from the Leptospermum species (Cokcetin, Pappalardo et al., 2016).

A naturally-occurring chemical compound called methylglyoxal (MGO) is responsible for much of the special activity of Manuka honey. This MGO comes from another chemical called dihydroxyacetone (DHA), which occurs naturally in the nectar of flowers of some Leptospermum plants.

The purpose of developing robust scientific criteria for identifying and defining Australian Manuka honey is to use a standardised approach to prove product authenticity, provide confidence for consumers, and distinguish Australian Manuka honey from other honey types to help mitigate against fraud.

Authenticating Australian Manuka honey

Australian Manuka honey can be pure monofloral Manuka (having ≥ 50% of the nectar derived from one floral source (Moar, 1985)), or a multifloral Manuka blend that also contains nectar collected by the bees from other floral sources. The level of various naturally occurring compounds in the honey will determine its level of activity.

Pure, active Australian Manuka honey

All honey defined and labelled as Active Australian Manuka and carrying the Australian Manuka Honey Association (AMHA) Mark of Authenticity logo, must be produced in Australia, and be tested by an independent approved laboratory to ensure it contains at least two of the following criteria when packed:

  • ≥ 85 mg/kg (or ppm) methylglyoxal (MGO)
  • ≥ 170 mg/kg (or ppm) dihydroxyacetone (DHA)
  • ≥ 50 mg/kg (or ppm) leptosperin

Research in Japan has also identified that there are some unique chemical identifiers present in Leptospermum honeys that are not found in regular honey, which makes it very easy to differentiate between fake product and pure, natural Manuka honey. Scientists have tested Australian Manuka honey for the unique chemical markers of Dihydroxyacetone, Leptosperin and Methylglyoxal, and have found them in abundance.

In order to provide consumers of Manuka honey with absolute confidence that the honey they are purchasing is pure 100% Australian Manuka, the AMHA has launched its Mark of Authenticity.

The Association’s Scientific Advisory Committee, comprising leading scientists in the field, has established a set of standards that define authentic Australian Manuka honey. Honey that carries the AMHA’s Mark of Authenticity must be pure, natural Manuka honey, produced entirely in Australia, and be tested by an independent, approved laboratory to ensure it meets minimum standards of naturally occurring methylglyoxal (MGO), dihydroxyacetone (DHA), and/or leptosperin.

These compounds are all naturally occurring in authentic Manuka. The level of MGO determines the potency of the honey, while the amount of DHA shows that this potency came naturally from the bees collecting Manuka nectar, Leptosperin is found in all Australian Manuka honeys, and according to the discoverer, Professor Yoji Kato, is a mark of Manuka authenticity. (Kato et.al. J. Agric. Food Chem 2012, 60, 3418-3423.)

Manuka honey for healing and combating superbugs

Manuka honey has significant value in a clinical setting where it can be used to beat superbugs and promote healing. Researchers in Germany, at the University of Dresden, were able to identify the active antibacterial component of the honey as methylglyoxal (MGO). This led MGO to replace NPA as the critical indicator of the strength of a Manuka honey. MGO is very accurate and is directly measurable by HPLC, unlike NPA and the old agar plate assay method which is over one hundred years old and prone to error.

Leptospermum flowers and the bioactive fraction of MGO originating from the nectar of Manuka flowers are the key driving force behind the antibacterial effect of Manuka honey. Research in Japan identified the unique chemical identifiers present in Leptospermum honey that are not found in regular honey, which makes it very easy to differentiate between a fake product and pure, natural Manuka honey. The AMHA have tested Australian Manuka honey for these unique Manuka markers and found them in abundance. This means that the Manuka honey you buy from Australia can be guaranteed as a pure, natural and authentic product.

References

Cokcetin, N, Pappalardo, M, Campbell, L, Brooks, P, Carter, D, Blair, S & Harry, E (2016). The Antibacterial Activity of Australian Leptospermum Honey Correlates with Methylglyoxal Levels. PLoS One, vol. 11, no. 12, p. e0167780.
Forst J and Forst G (accessed March 20, 2018). Leptospermum, Atlas of Living Australia
https://bie.ala.org.au/species/https://id.biodiversity.org.au/node/apni/8499083
Moar, N (1985). Pollen analysis of New Zealand honey. New Zealand Journal of Agricultural Research, 28:1, 39-70.
Molan, P & Russell, K (1988). Non-peroxide antibacterial activity in some New Zealand honeys. J. Apic. Res.27: 62–67.