Honey, It's a Winner
Elaine Reeves, The Mercury, 9/23/2009
Time was when beekeepers tried to avoid collecting honey from tea-trees.
It's hard to get a reliable flow from it, hard to extract and hard to pack," says Robbie Charles of Blue Hills Honey.
He has a picture of his father Rueben having uncapped the combs, stacking them in the river to wash out the dense jelly-like honey that otherwise had to be scraped away.
Because tea-trees are among the first to flower, it had some value for building up the bees to take advantage of the leatherwood flow that comes after Christmas.
One year Robbie and Nicola Charles had 14 tonnes of the stuff stacked up to be used for feed over the winter. That was all before the New Zealand name for tea-tree -- manuka -- was adopted by apiarists. They are both names for Leptospermum scoparium, but it makes sense to adopt the Maori name since that is the one recognised for the antifungal and antibacterial effects of "healing honey"…
Some manuka honey can have 1000 times the antibacterial power of other honeys, but all manuka honeys are not alike.
The way of measuring the potency until recently was to rate the "unique manuka factor" or UMF, by measuring the efficiency of the honey against a standard disinfectant. The honey was rated from 5 to 20 UMF.
About a year ago, Thomas Henle of the University of Dresden published findings that identified methylglyoxal as the compound in manuka honey that had the antibacterial effect.
The methylglyoxal level can be measured with a direct chemical analysis, and is a more reliable method than measuring the honey against a disinfectant -- plus the honey does not need to be sent to New Zealand for assessment.
The methylglyoxal is rated in milligrams per kilo. A measure of 30+ is equivalent to 5 UMF, and 400+ of methylglyoxal equals 20 UMF.
Only analysis will confirm the presence of methylglyoxal, but Robbie says he tends to know what areas produce the higher grades now.
"The poorer and the rougher the soil is, the better activity there is," he said. Quality can also depend on the variety of manuka -- some 83 different tea-trees grow in Tasmania - and where it grows…
He recently analysed Tasmanian honeys from 10 apiarists for their antioxidant content. Prickly box honey rated highest, and leatherwood from the North West, where Robbie and Nicola operate, was not far behind, but leatherwood from the South had less than half the levels of that from the North West. Manuka, tallow wood and Pedder wildflower honeys were also high in antioxidants.
Now there are moves afoot to obtain funding to test leatherwood honeys for their anti-inflammatory properties…