aidilla mubarak - final web - uwa institute of agaidilla mubarak school of medicine and pharmacology...
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Aidilla Mubarak School of Medicine and Pharmacology and School of Plant BiologyFaculty of Medicine, Dentistry and Health SciencesFaculty of Natural and Agricultural Sciences
Aidilla completed a Bachelor of Science degree with Honours in Molecular Bioscience, followed by a Masters in Nutrition in her home country of Malaysia. After working as an academic fellow and later a tutor in the Department of Agriculture and Food Science, at the Universiti Malaysia Terengganu, she was sponsored by the government of Malaysia to undertake full-time PhD at UWA. Upon completion of her PhD she will take up a lecturing position at her former university in Malaysia.
Her current research investigates the links between plant polyphenol compounds and dietary health. Dietary polyphenols have been associated with reduced risk of cardiovascular disease. Fruit such as plums are a rich source of polyphenolic antioxidants. The objective of her study was to evaluate and quantify total phenolic content, selected individual polyphenols and total antioxidant capacity in 32 new Western Australia plum cultivars.
Plum Polyphenol Composition In Relation To Total Antioxidant Capacity
Aidilla Mubarak
Supervisors: Assc. Prof Michael Considine, Prof Kevin Croft, Prof Jonathan Hodgson
The UWA Institute of Agriculture
Acknowledgement
• Supervisors• Dr Ewald Swinny (ChemCentre)• Dr Simon Ching (PathWest)• Department of Agriculture and Food, Western Australia
• ARC (LP0882884) • Malaysian Ministry of Higher Education
Polyphenols
Secondary metabolites of plants
Widely dispersed in plants
Diverse biological functions
Chlorogenic Acid CatechinQuercetin
Why is polyphenol important?
Quality in fruits
• Visual appearance
• Taste
Interest from consumers and food manufacturers. Why?• Prevention of diseases• Acts an antioxidant
• Most abundant antioxidant from diet
Why is polyphenol important?
Dietary sources
Distribution In Fruits
Varies with different factors
Different cultivar Storage condition
0
100
200
300
400
500
600
700
Empire McIntosh Cortland Red Delicious Northern Spy
Concentrationµg/g FW
Apple Cultivars
Polyphenol distribution in apple skin of different cultivars
Catechin
Epicatechin
Tsao et al, J. Agric. Food Chem., 2003, 51 (21), pp 6347–6353
0
20
40
60
80
100
120
140
Cortland Cortland Red Delicious Red Delicious
Concentration µg/g FW
Apple cultivars
Polyphenol distribution in apple skin and flesh
Chlorogenic acid
Catechin
Skin Flesh Skin Flesh
Tsao et al, J. Agric. Food Chem., 2003, 51 (21), pp 6347–6353
Information on phenolic content • few cultivars• single group of compounds
Polyphenol compositions among different cultivars of plums is important – breeding program
Research Objective
To quantify polyphenols and antioxidant capacity of 32 new Western Australia plum
cultivars (DAFWA)
To demonstrate a correlation between polyphenols composition and the
antioxidant capacity
Methods
Selected individual polyphenol identified & quantified:
Reversed‐phase HPLC‐DAD
Total phenolic content measurement:
Folin Ciocalteu’s colorimetric reaction
Total antioxidant capacity quantified:
Antioxidant inhibition of oxygen radicals (AIOR) assay
32 Western Australian Plum
Major polyphenol compound in plums
• Neo‐chlorogenic acid Mean: 29 ± 54 mg/kg Range: 0 – 221 mg/kg
• QuercetinMean: 52 ± 41 mg/kg Range: 9 ‐ 240 mg/kg
0
50
100
150
200
250
300
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32
Conc. (mg/kg)
Plum cultivars
Neo‐chlorogenic acid
Quercetin
Variation of polyphenol amongst cultivars
0
200
400
600
800
1000
1200
1400
1600
1800
2000
1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31
TPC (mg/kg GAE)
Plum cultivar
Mean: 701 ± 322 mg/kg GAERange: 222 – 1711 mg/kg GAE
Total Phenolic Content in Plum
0
5000
10000
15000
20000
25000
30000
35000
40000
1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31
TAC (mol/kg TE)
Plum cultivar
Mean: 13720 ± 6142 mol/kg TERange: 4795 – 36187 mol/kg TE
Total Antioxidant Capacity in Plum
Relationship of total antioxidant capacity with measured polyphenol content
Measurements N Pearson Correlation
Sig. (2‐tailed)
Total Phenolic Content
32 0.954 ** 0.000
Neo‐chlorogenic acid content
32 0.242 0.182
Quercetin content 32 0.180 0.324
Conclusion
Total phenolic content – positive relationship with the antioxidant capacity (P<0.001)
Neochlorogenic acid & quercetin glycoside –predominant polyphenols
Do not individually account for the antioxidant capacity
Future analysis
• Ascorbic acid, glutathione and total thiols
• Controlled human intervention study: effect of chlorogenic acid on cardiovascular function
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