Identifying iron-binding antioxidants in New Zealand honeydew honey
type: CreativeWork
description: Iron is an essential element for human physiological function. However, excess free iron could participate in the formation of reactive oxygen species via the Fenton reaction and is thought to be the primary mechanism for the pathogenesis of diseases related to iron excess. Prevention of the oxidative damage caused by reactive oxygen species can be accomplished by using selective iron-binding compounds. Beech honeydew honey has been found to have an exceptionally high level of iron-binding antioxidant activity. Due to that, the focus of the research in this thesis has been to isolate the compound(s) responsible for the activity and identify their molecular structure. The stability of the antioxidants on exposure to heat and high and low pH was investigated to get a better understanding of the conditions which could be used when developing suitable techniques for the isolation of the iron-binding antioxidants. The isolation of the antioxidants was first attempted with XAD-2 resin. The results of solid phase extraction using XAD-2 resin showed that the activity is mainly found in the honey effluent, the fraction not retarded by the resin, indicating that hydrophilic components contributed to the iron-binding antioxidant activity. The phenolic compounds isolated from this resin did not exhibit iron-binding antioxidant activity. When the antioxidants could not be isolated from the XAD-2 resin, size exclusion chromatography was used to separate the honey components based on their molecular sizes. The technique was successsful in separating antioxidants from free sugars in honey. However, size exclusion chromatography did not give any significant information regarding the identity of the antioxidants. Thus, two types of chromatography (reversed phase and anion exchange) were used in sequence to aid the separation of components of the active fraction from size exclusion chromatography. This procedure however was not compatible with subsequent mass spectrometry since a high…
abstract: Iron is an essential element for human physiological function. However, excess free iron could participate in the formation of reactive oxygen species via the Fenton reaction and is thought to be the primary mechanism for the pathogenesis of diseases related to iron excess. Prevention of the oxidative damage caused by reactive oxygen species can be accomplished by using selective iron-binding compounds. Beech honeydew honey has been found to have an exceptionally high level of iron-binding antioxidant activity. Due to that, the focus of the research in this thesis has been to isolate the compound(s) responsible for the activity and identify their molecular structure. The stability of the antioxidants on exposure to heat and high and low pH was investigated to get a better understanding of the conditions which could be used when developing suitable techniques for the isolation of the iron-binding antioxidants. The isolation of the antioxidants was first attempted with XAD-2 resin. The results of solid phase extraction using XAD-2 resin showed that the activity is mainly found in the honey effluent, the fraction not retarded by the resin, indicating that hydrophilic components contributed to the iron-binding antioxidant activity. The phenolic compounds isolated from this resin did not exhibit iron-binding antioxidant activity. When the antioxidants could not be isolated from the XAD-2 resin, size exclusion chromatography was used to separate the honey components based on their molecular sizes. The technique was successsful in separating antioxidants from free sugars in honey. However, size exclusion chromatography did not give any significant information regarding the identity of the antioxidants. Thus, two types of chromatography (reversed phase and anion exchange) were used in sequence to aid the separation of components of the active fraction from size exclusion chromatography. This procedure however was not compatible with subsequent mass spectrometry since a high…
author: Omar, Syaliza Binti
keywords: antioxidants, honey
license: https://researchcommons.waikato.ac.nz/bitstreams/108d6a8e-a6a7-4ae0-9f50-62eb28a2ae6f/download
date published: 2013
date modified: 2026-07-24T05:57:21Z
provider: University Waikato
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: University of Waikato