Analysis of Amino Acids in Mānuka Honey

Lloyd, Alicia Marie

Analysis of Amino Acids in Mānuka Honey

dc.contributor.advisor	Manley-Harris, Merilyn
dc.contributor.author	Lloyd, Alicia Marie
dc.date.accessioned	2017-02-23T01:24:13Z
dc.date.available	2017-02-23T01:24:13Z
dc.date.issued	2015
dc.date.updated	2015-02-26T19:59:52Z
dc.description.abstract	Honey, a natural product produced by honeybees, has a complex matrix of sugars proteins, minerals, vitamins, enzymes and free amino acids. Amino acids, obtained from the nectar of plants, account for 50-30 mg/kg of honey, the most abundant of which is proline, a secondary amino acid originating mainly from the haemolymph of bees. Three methods were investigated for the analysis of amino acids in honey. The first used HPLC-UV with pre-column derivatisation, the second HPLC-MS with hydrophobic interaction chromatography, and finally HPLC-MS with aTRAQ™ derivatisation. The HPLC-UV method involves derivatisation of amino acids by OPA-MPA and FMOC. A fully automated injection program analysed seventeen primary amino acids in 19 minutes. Ultimately, the detection by UV had inadequate sensitivity, and the secondary amino acid proline could not be detected. The method was rejected for these main reasons. ZIC-pHILIC chromatography paired with LC-MS-MS gave high-quality separation of twenty one amino acids, detected using scheduled MRM, in 10 minutes. Amino acid recovery out of vial was low for the majority, this variation originating from sample preparation. In vial loss of amino acids could not be recovered and so investigation into the last method was initiated. The final method used an aTRAQ™ kit which labels amino acids with a Δ8 reagent for analysis and also provides Δ0 labelled internal standards for comparison. Forty eight amino acids and internal standards can be accurately detected by MRM’s in 18 minutes. Sample preparation was optimised for honey and the method was validated. The amino acid content of ten honeys were compared to values obtained from Massey University. Small differences in the majority of amino acids were observed. Mānuka and clover honeys from this data set were also compared, it was found that phenylalanine and tyrosine were at much higher concentrations in clover honey. Seven mānuka honeys stored in different conditions, warm and cold, were analysed. Applied statistical analysis with the hypothesis that the warm honeys would have lower amino acid concentrations than the cold, found this to be true for seventeen amino acids. Glutamine and then lysine were at decreased concentrations after warm storage in the most honey samples. The amino acid content of honey, analysed by this method can be used to investigate: botanical origin of honey, speed of honey production/harvest, effect on DHA conversion, inaccurate labelling, and sugar syrup addition.
dc.format.mimetype	application/pdf
dc.identifier.citation	Lloyd, A. M. (2015). Analysis of Amino Acids in Mānuka Honey (Thesis, Master of Science (MSc)). University of Waikato, Hamilton, New Zealand. Retrieved from https://hdl.handle.net/10289/10906	en
dc.identifier.uri	https://hdl.handle.net/10289/10906
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	Amino acid
dc.subject	Honey
dc.title	Analysis of Amino Acids in Mānuka Honey
dc.type	Thesis
pubs.place-of-publication	Hamilton, New Zealand
thesis.degree.grantor	University of Waikato
thesis.degree.level	Masters
thesis.degree.name	Master of Science (MSc)