Irish heather honey ‘comparable to manuka honey’ in antioxidant properties

3 Sep 2018

PhD student Saorla Kavanagh. Image: DCU

A study comparing Irish honey samples with international brands found Irish heather honey packing as many antioxidant compounds as New Zealand’s manuka honey.

Honey is a staple in many a store-cupboard, thanks to its sweet taste and its suggested benefits to our overall health attributed to antioxidant and antimicrobial properties. Manuka honey, in particular, is favoured by the health-conscious and often sold as an alternative medicine.

The medicinal quality attributed to manuka honey comes from the presence of phenolic compounds. These are ubiquitous in plants and an essential part of the human diet, but they are of particular interest in scientific research because of their antioxidant properties.

New Irish research has shown, though, that the manuka variety might not have the monopoly on high-quality honey.

With funding from the Irish Research Council, Dublin City University (DCU) PhD student Saorla Kavanagh led a research project focused on honey produced in Ireland. This research examined the phenolic content and physicochemical parameters (such as moisture, total sugar and colour) of different types of Irish honey and compared these with international brands.

From 2013 to 2015, beekeepers across Ireland donated a total of 131 Irish honey samples from 78 locations to the study. Most of these (124) were multi-floral honeys, three were heather honeys, two were ivy honeys and two were oilseed rape honeys.

It is believed that a higher total phenolic content (TPC) means a higher antioxidant capacity in a honey, and it was established that the Irish heather honey had the highest TPC of all Irish single-origin honeys. Not only that, but it had a higher TPC than the world-famous manuka honey.

‘Our research shows that Irish honey is a high-quality product and something that we should really value’

Kavanagh’s research is supervised by senior academics Dr Blánaid White of DCU and Prof Jane Stout of Trinity College Dublin.

“Being able to quantify that Irish honeys have a high phenolic content and, particularly, that the content in Irish heather honey is comparable to manuka honey, is very exciting for us,” said White. “Our research shows that Irish honey is a high-quality product and something that we should really value. Interest in beekeeping and honey production is growing in Ireland, and we are delighted to be able to support it.”

The study suggests that differences in TPC could be linked to landscape context, specifically the principal land use surrounding sampled hives. For example, there was significantly less TPC in honeys from rural versus urban areas.

“Because bees can forage up to several kilometres from their hives, the availability of food sources (ie flowers) in the wider landscape influences what the bees collect and incorporate into their honey,” explained Stout. “Finding a difference in honey composition between urban and rural hives probably reflects the difference in flower availability in urban and rural areas in Ireland.”

These findings have been published in the journal Food Chemistry.

Elaine Burke is the editor of Silicon Republic