FREQUENTLY ASKED ACTIVITY IN HONEY QUESTIONS
WHAT IS ACTIVITY IN HONEY?
Total Activity (TA) is like bacterial and fungal killing scale, the bigger the value, the more bacteria (and fungus) the honey can potentially kill. Values above TA10 deliver beneficial properties, while values of, or above TA30+ are exceptional and have great health benefits.
TA is the sum of two types of antimicrobial power in Honey: Peroxide Activity (PA) and Non Peroxide Activity (NPA).
TA = PA + NPA
What is PA and NPA you ask…
Peroxide Activity (PA) is the natural antimicrobial and antifungal power that bees have developed over millions of years of evolution to protect their honey from microbial infection as it forms (ripens) in the beehive. The PA results from a chemical reaction between a bee enzyme called glucose oxidase (GO), glucose and water. The reaction proceeds for as long as the unripened honey contains free water and yields a low concentrations of hydrogen peroxide that is lethal to the microbes attempting to colonise the honey, plus gluconic acid which also inhibits microbial growth.
PA is active as the nectar ripens but stops when the honey has formed and is dehydrated. Subsequent preservation of the honey is achieved by the low water activity and acidity. In most honeys, the GO is depleted by the time the honey ripens so it has no remaining PA. High PA honeys have residual GO which is reactivated when the honey is diluted with water, for example when you eat it (and it mixes with saliva) or put on a skin wound.
High PA honey is highly effective against many bacterial and fungal infections, plus some parasites and viruses. The PA is gentle on human tissue and the digestive system, so it can be used as an antiseptic drink (diluted or raw), and topically. But please always consult your doctor before using high PA honey to treat a wound, as the effectiveness can be diminished in situations where the enzyme catalase is present (for example if blood is present).
PA also has no adverse effect on the taste of the honey.
Non-Peroxide Activity (NPA) includes all the antimicrobial power that is derived from phytochemicals in the nectar that bees collect from flowers, plus the acids in the honey. Trees produce many phytochemicals to protect themselves from bacterial infection and other purposes, and some of these chemicals can be present in the nectar. When the bees convert the nectar to honey, the chemicals become much more concentrated and Active. However, these chemicals often give the honey a bitter or antiseptic flavour.
The most potent NPA phytochemical is methyl glyoxal (MGO) which is found in Manuka honey. NPA is typically unaffected by catalase.
MGO is a toxic chemical and can be harmful to people with diabetes. It is recommended that only Manuka honey with UMF15 (MGO 515) or lower be eaten on a regular basis. Honey with higher UMF values should be eaten intermittently or used topically.
YES! When we eat the honey, or apply it to a wound on our skin, the honey absorbs water and the PA reaction starts again. It results in a gradual production of a low concentration of hydrogen peroxide, a powerful anti-bacterial and anti-fungal agent, which becomes more powerful when operating in conjunction with honey’s other antiseptic properties. However, it is gentle on human tissue and the digestive system, so it can be used as an antiseptic drink (diluted or raw), and topically (but always consult your GP before using to treat large wounds).
In most applications, PA and NPA have the same antimicrobial effect, so when comparing Active honeys like Jarrah with Manuka: TA = UMF.
The TA of all Forest Fresh honey is measured by the ChemCenter in WA by Well Diffusion Phenol Equivalent (WDPE) analysis, a method developed in New Zealand in the early 1990’s to measure the Activity of Manuka honey. In this test, a sample of honey diluted with water (a ratio of 1:1 to 1:3) is placed in a hole (well) cut into a thin layer of agar hosting a common bacterium (e.g., Staphylococcus aureus). The diluted honey slowly diffuses out into the agar and inhibits the growth of the bacteria. The width of the inhibitory zone after 24 hours is compared with the zone width produced by a standard of a diluted Phenol solution (a strong organic antiseptic and disinfectant). Honey with TA10 has 10% of the Phenol power and so on.
The ChemCenter now advises that WDFE can accurately determine TA of PA dominant honey over the range of 5 to 35 (* previously 40, see note below). There is now no certified analytical method that can accurately measure PA above 35. Forest Fresh Jarrah honey typically yields uncorrected TA values much higher than the upper range (the highest to date is TA65), but because of the unreliability of these very big values, the Certificates of Analysis (CoA) issued by the ChemCenter are capped at TA35+.
*Up to early 2020 the ChemCenter reported TA values to a maximum of 40, but they subsequently revised this upper value down to 35. Forest Fresh has a stock of TA40+ certified Jarrah honey and is entitled to label it at this value. However, once this stock is gone, TA35+ will be the maximum label value. Consumers of Jarrah honey should be aware that any honey being sold at greater than TA40+ is not supported by a CoA from the ChemCenter (or any other NATA accredited laboratory), so they should purchase with caution.
The terms UMF, NPA, and MGO apply only to Manuka honey.
UMF (the abbreviation of “Unique Manuka Factor”) is a trademarked name for the NPA used by some Manuka producers and packers. Most Manuka honey has UMF between 5 and 25, and very rarely up to about 30. Manuka has almost no PA, so for this honey TA = NPA = UMF.
The NPA of Manuka honey was once determined by WDFE but is now determined by assay of the MGO content, which is reported as mg/kg. MGO values for Manuka range from about 85mg/kg (equal to UMF5) and 1200 mg/kg (about UMF25). The NPA/UMF is then calculated by reference to a standard curve developed by assaying many samples for both NPA (by WDPE) and MGO and determining the transpositional mathematical formula.
A comparison of TA, UMF and MGO is shown in the table and graph below.
1. Manuka with UMF>30 is exceedingly rare (so not commercially available). Most Manuka has UMF <20.
2. The MGO values are in mg/kg.
3. In some topical applications where the enzyme catalase is present (eg in the presence of blood) high PA honey will have a lower antimicrobial power compared to equivalent NPA honey owing to the catalase absorbing most peroxide before it can be effective. We strongly advise that the use of any honey as a topical antimicrobial only be undertaken with the guidance of a qualified medical practitioner.