A Survey of Dihydroxyacetone in Nectar of Leptospermum Scoparium from Several Regions of New Zealand

Williams, Simon Douglas

A Survey of Dihydroxyacetone in Nectar of Leptospermum Scoparium from Several Regions of New Zealand

dc.contributor.advisor	Manley-Harris, Merilyn
dc.contributor.author	Williams, Simon Douglas
dc.date.accessioned	2014-08-01T04:40:56Z
dc.date.available	2017-02-21T02:37:05Z
dc.date.issued	2012
dc.date.updated	2012-02-23T22:10:51Z
dc.description.abstract	Mānuka honey has been identified as having non-peroxide antimicrobial activity (NPA). This medical benefit has led to mānuka honey becoming a major export for New Zealand. Hives are currently located in preserved or regenerating mānuka bush. With the growth in the mānuka honey industry, interest has arisen to determine why mānuka trees produce the non-peroxide active honey. Identification of this reason will allow mānuka plantations to be planted that are expected to provide honey with a high level of non-peroxide activity. These plantations will also allow marginal land to become more productive due to mānuka being a resilient plant able to grow under harsh conditions. It has been shown that the majority of the non-peroxide activity arises from the presence of methylglyoxal (MGO). In fresh honey a minimal amount of MGO was present, but a large amount of dihydroxyacetone (DHA) was found. Previous work has shown that DHA can undergo chemical conversion into MGO under the correct conditions. A similar conversion is postulated to take place in honey, testing suggests that this conversion is a non-enzymatic reaction. Preliminary surveys have been carried out which have identified DHA in the nectar of mānuka owers. This thesis describes a wider survey of mānuka trees around New Zealand.The trees were sampled in the flowering seasons of 2009 and 2010 between October and January. Flowers were picked and frozen for processing and an aqueous soaking method was developed to extract the DHA and sugar from a pooling of 20 owers. Analyses of the samples were carried out by gas chromatography with flame ionisation detection. This method was further improved to include the nectar extraction and measurement of DHA levels within a single flower. To allow the DHA to be related back to honey, it was measured in ratio to the total sugar (Tsugar) in the nectar to give the ratio DHA/Tsugar. It was confirmed that DHA/Tsugar measured in the nectar of the mānuka flower does vary within and between the regions surveyed. Suggested causes of within region variation are the age of the tree, micro-environments and possibly genetics. Variation between regions is strongly suggested to be genetically linked. Using the work by Adam set al.(2008, 2009), it was possible to predict honey NPA values based upon the DHA/Tsugar found in the nectar and these values were comparable with the measured NPA of the honey as supplied by beekeepers. Only a poor correlation of DHA/Tsugar was found with the soil components measured by Kiefer(2010); with the leaf oil components measured by Janusch(2010) some correlation was found, when these were correlated across all the sampled regions. When each region was correlated individually, the correlation proved much stronger, suggesting a link, though most likely indirect, to the mānuka oil chemotype. Using these survey results, mānuka trees have been identified for the purpose of breeding and on-going study.
dc.format.mimetype	application/pdf
dc.format.mimetype	application/zip
dc.identifier.citation	Williams, S. D. (2012). A Survey of Dihydroxyacetone in Nectar of Leptospermum Scoparium from Several Regions of New Zealand (Thesis, Master of Science (MSc)). University of Waikato, Hamilton, New Zealand. Retrieved from https://hdl.handle.net/10289/8764	en
dc.identifier.uri	https://hdl.handle.net/10289/8764
dc.language.iso	en
dc.publisher	University of Waikato
dc.rights	All items in Research Commons are provided for private study and research purposes and are protected by copyright with all rights reserved unless otherwise indicated.
dc.subject	dihydroxyacetone
dc.subject	leptospermum scoparium
dc.subject	manuka
dc.subject	mānuka
dc.subject	nectar
dc.subject	flower
dc.subject	New Zealand
dc.subject	PFBHA
dc.subject	leaf oil
dc.subject	gas chromatography
dc.subject	Flame Ionisation Detector
dc.subject	GC-FID
dc.title	A Survey of Dihydroxyacetone in Nectar of Leptospermum Scoparium from Several Regions of New Zealand	en
dc.type	Thesis	en_NZ
pubs.place-of-publication	Hamilton, New Zealand	en_NZ
thesis.degree.grantor	University of Waikato
thesis.degree.level	Masters
thesis.degree.name	Master of Science (MSc)