Identifying iron-binding antioxidants in New Zealand honeydew honey

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 level of sodium chloride existed in the final fraction, even after desalting using reversed phase column chromatography. Due to that, other means of chromatography were trialled in order to obtain a salt-free fraction prior to mass spectrometry. The first procedure was modified by switching the sequence of the columns used, and different mobile phases without salt were used. This second procedure was successful in isolating the antioxidants and the compounds have been characterised by mass spectrometry. Mass spectrometry revealed that the antioxidants isolated were compounds of low molecular weight (i.e. 255, 283 and 227) which exhibited peaks with high intensity. Nuclear magnetic resonance (NMR) spectroscopy of the active fraction showed that the antioxidant may possess a 1,4-disubstituted aromatic ring. However, full elucidation of the structure of the compound was not possible because of the very low mass of the material that had been isolated. Other than the information gained from mass spectrometry and NMR, the antioxidant also could be characterised by forming the negative ion at pH 9.5–10. The UV absorbance at 220 and 280 nm, but not at 360 nm is indicative that the antioxidant possess a phenolic ring but not a flavonoid in the molecular structure. Complete structural elucidation of the iron-binding antioxidants in honeydew honey could initiate a better understanding of the mechanism of action of the antioxidants. This could increase the use of honeydew honey in pharmaceutical and nutraceutical products as an iron-binding antioxidant. There is also the possibility that the identified compound(s) could be synthesised for pharmaceutical use, or serve as lead compounds for the development of other pharmaceutical iron-binding antioxidants

Antibacterial activity of Malaysian produced stingless-bee honey on wound pathogens

The antibacterial activity of Malaysian stingless bee honey was tested on six common wound pathogens using agar well diffusion. All pathogens showed varying degrees of susceptibility to undiluted and diluted honeys produced by Geniotrigona thoracica of multifloral source (GTM) and Melastoma malabathricum L (Senduduk). Multifloral honey from Heterotrigona itama (HTM) failed to inhibit the growth of all pathogens, except for methicillin-resistant Staphylococcus aureus (MRSA) which has demonstrated moderate susceptibility to undiluted honey. It was found that the antibacterial activity of GTM and Senduduk honeys were concentration dependent. The minimum inhibitory concentration (MIC) assay showed that a lower value (3.13% v/v) was observed with GTM honey for all pathogens and Senduduk honey for Streptococcus pyogenes, MRSA, Staphylococcus aureus and Pseudomonas aeruginosa, respectively. Interestingly, HTM honey showed MIC between 6.25 to 12.5% (v/v) in microdilution method. The minimum bactericidal concentration (MBC) of GTM honey ranged between 6.25 to 12.5% (v/v), whereas Senduduk and HTM honeys showed MBC of 25% (v/v). The lower MIC and MBC values exhibited by GTM honey indicate s potent antibacterial activity as seen in this honey. This study revealed that the Malaysian stingless bee honeys have promising antibacterial activity against wound pathogens, and this type of honey could be used as an alternative in treating infected wounds

Effect of thawing conditions and corresponding frying temperature profiles on the formation of acrylamide in French fries

This study attempted to determine the effects of thawing conditions and corresponding frying temperature profiles on the formation of acrylamide in French fries. Frozen par-fried potato strips were thawed under three different conditions, at room temperature, using a chiller, and using a microwave. Unthawed par-fried potato strips were used as the control samples. Thawed (or unthawed) par-fried potato strips were deep-fat fried in palm oil at 180 ± 5 °C for 3.5 min. The temperature drop was monitored every 15 s for a total of 6 min; 3.5 min of frying time plus an additional 2.5 min until the oil temperature returned to 180 °C. The acrylamide content, oil content and colour of the French fries were measured. The frying temperature dropped substantially (more than 30 °C) from the initial temperature in the first 45 s of frying for all thawing conditions. After 90 s of frying, the smallest temperature drops were observed for French fries thawed using a microwave (20%), and the largest temperature drop prior to recovery was seen with the control sample (24%). At the end of the frying period (after 210 s), French fries thawed using a microwave had reached the highest final temperature (154 °C), and the control sample had reached the lowest final temperature (145 °C). The acrylamide contents of the French fries were found to be in the range of 77.4–106 ng/g, whereas the oil contents ranged from 16.4 to 20.5%. The lowest lightness, highest redness and highest yellowness were found for French fries thawed using a microwave. Although the thawing conditions did not significantly affect the formation of acrylamide, microwave thawing was found to be the best thawing method due to the resulting (relatively) low acrylamide and oil contents of the French fries and their desirable colour attributes. The results of this study can be used to recommend that the manufacturers of frozen par-fried potato strips specify the use of a microwave for thawing as part of the frying instruction on the packaging

Determination of total phenolic contents and antioxidant capacity in Malaysian unifloral honeys / Syaliza Omar, Maisarah Abdul Hamid and Norhilmiah Hayati Mohd Yaacob

The main objectives of this project are to determine total phenolic content, antioxidant content in honey and to identify correlation between total phenolic content and antioxidant activity. This study has been performed by using reagent; Folin-Ciocalteu reagent for determining total phenolic content and DPPH reagent for determining antioxidant content of honey. All honey samples were dissolved in distilled water to produce desired concentration. The dissolved honeys were subjected for Folin-Ciocalteu method and DPPH method. Spectrophotometer was used to determine the desired compound at 760 nm for total phenolic content and 5 17 nm for antioxidant content. The graph of total phenolic content against antioxidant activity was plotted to identify correlation between total phenolic content and antioxidant content. The results showed that the duran honey had the highest total phenolic contents, while gelan1 honey represented the highest antioxidant capacity of all honeys tested. Total phenolic contents and antioxidant capacity have been found to be dose-dependant

Effect of contact time on the level of phthalates in polyethylene terephthalate-bottled water from the point of sale

The study aimed to evaluate the effect of contact time on the level of phthalates in polyethylene terephthalate (PET)-bottled water commercially available on the market. Different water types (drinking water, mineral water, and sparkling water) in PET bottles and mineral water in glass bottles were collected. Control (before bottling) and freshly produced (0-month) samples were collected at manufacturing sites. In contrast, samples at 6, 12, and 18 months of contact times were collected randomly from hypermarkets and supermarkets in Klang Valley, Malaysia. The samples were analyzed using LC-MS/MS with deuterated DEHP as the internal standard. DEHP, DMP, DEP, DnOP, and BBP were not detected in drinking, mineral, and sparkling water in both PET and glass bottles. However, DBP was detected within the range of 0.68 to 1.11 ng/mL for mineral water and 0.55 to 0.59 ng/ mL for drinking water in PET bottles. All types of phthalates, including DBP, were not detected in the control and 0-month samples. DBP was detected at 0.59 ng/mL at 6 months of contact time and 0.55 ng/mL at 12 months of contact time in PET-bottled drinking water samples; the difference, however, was not significant. It appears that contact time did not significantly affect DBP levels

The effects of storage temperature and time on the levels of phthalates in commercial PET-bottled water

This study was conducted to determine the effects of storage temperature and time on the levels of phthalates in commercial PET-bottled water. Freshly-produced water samples consisted of drinking, mineral, and sparkling in PET bottles were collected from a manufacturing site and subjected to different storage temperatures (refrigeration temperature of 4 °C, room temperature of 25 °C, and 40 °C) and times (0 month as control, 1.5 months, 3 months, and 6 months). Six different phthalates were analyzed using LC-MS/MS with deuterated bis(2-ethylhexyl)phthalate (DEHP) as internal standard. DEHP in the PET-bottled water was detected in the range from 2.32 to 27.6 ng/mL for 3- and 6-month storage samples; higher than di-n-octyl phthalate (DnOP) detected in the range from 1.57 to 12.6 ng/mL. Higher levels of DEHP and DnOP in PET-bottled mineral water were detected at room temperature of 25 °C when compared to refrigeration temperature of 4 °C, and 40 °C at 6-month storage. Higher level of DEHP and DnOP in drinking water was found at 6 months compared to 3 months in refrigeration temperature of 4 °C. The pronounced effects of storage temperatures on the levels of phthalates was observed only after 6 months of storage in which DEHP levels exceeded the maximum established limit of 6 ng/mL

Conceptualising the influence of total quality management and organizational performance in Klang Valley service industry

Studies on Total Quality Management (TQM) practices in service industry are scarce. This conceptual study sought to investigate the TQM best practices dimensions that could be applied by the service industry. The research in TQM in Malaysia have been explored quite extensively focusing particularly on manufacturing industry but not in other industry including service industry. The preliminary result indicated that seven dimensions of TQM could be applied for TQM best practice. The discussion and arguments in this conceptual study would be used further in the actual study to address the lacuna in research on TQM and provide insights for organizations to use TQM best practices in the service industry today. The main aim of this study is to determine the best practice dimensions of TQM in Malaysia’s service industry, taking into consideration the dimensions proposed by previous research (i.e.: leadership, supplier management, strategic planning, human resource management, customer focus, information and analysis and process management). This study will further identify how TQM could influence service industry organizational performance in Malaysia to fill the gap in TQM and service industry

Assessing the performance of Food Safety Management System using Food Safety Management System Diagnostic Tools and Microbial Assessment Scheme: A case of powdered beverage manufacturers

Background: The objective of the study is to assess the performance of the Food Safety Management System (FSMS) among powdered beverage manufacturers using Food Safety Management System Diagnostic Tools (FSMS-DI) and Microbial Assessment Scheme (MAS). Methods: FSMS-DI was used to evaluate the context factors, core control and core assurance activities of five powdered beverage manufacturers with different types of FSMS certification. Manufacturer A is not certified with any FSMS, while manufacturers B, C, D and E are complied with MeSTI, GMP, HACCP and ISO 22000, respectively. For MAS, samples were collected from the selected critical sampling locations of two manufacturers who complied FSMS with the least (manufacturer B) and the most stringent (manufacturer E) requirements. The samples consisted of two different types of powdered beverage products were analysed for total plate count (TPC), Salmonella, Escherichia coli, Staphylococcus aureus, yeast and mould count (YMC). Results: The food safety (FS) output of powdered beverages for manufacturer E was better (overall score of 3) than manufacturer B (overall score of 2–3). Manufacturer E was able to achieve their FS objectives. The FSMS activities of manufacturer C, D and E were better (overall score of 2–3) than manufacturer A and B (overall score of 1–2). Conclusion: The study demonstrated that FSMS-DI and MAS can be used to differentiate the FSMS performance of powdered beverage manufacturers with different types of FSMS certification. Higher scores of FSMS activities obtained by the manufacturer who complied with stringent FSMS certifications contributed to better microbiological safety performance of powdered beverages