Kueh, Adrian Tow Tze Phin (2009) Determination of selected polyphenols in Cameron tea leaves of different maturity. Universiti Malaysia Sabah. (Unpublished)
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Abstract
This study is to determine and compare the proximate composition (crude protein, crude fat, crude fibre, ash content and carbohydrate content), content of flavanols (EGCG, EGC, ECG and EC) and f1avonols (quercetin and kaempferol) in Cameron tea leaves of different maturity stages. Young tea leaves comprised of the apical bud and the terminal two leaves, mature leaves of the third to fifth leaves, while old tea leaves were of the sixth leaves and onwards. A sample of commercialized tea leaves (Boh Cameron Tea - green tea) was analysed as well to compare it to fresh tea leaves. Analysis was done by means of the high performance liquid chromatography (HPLC). Separation of flavanols was achieved using a RP18 column and a gradient elution system of (A), 0.1% orthophosphoric add in water and (8), acetonitrile. As for the investigation of flavonols, a C18 reversed phase column with an isocratic elution of the mobile phase 30% acetonitrile in O.025M KH2P04 buffer solution was used. Young tea leaves and commercial leaves contained, in order of decreasing concentrations, EGCG > EGC > ECG > EC. As for mature leaves, it is EGC > EGCG > ECG > EC. Old leaves composition was EGC > EGCG > EC > ECG. The highest EGCG content was found in young leaves at 38.58mg/g. The EGCG level was also significantly higher (P<0.05) than those in mature and old leaves. On the other hand, old leaves had the highest amount of EGC (37.37mg/g) and it was significantly higher (P<0.05) than young and commercial leaves. Quercetin and kaempferol content was highest in young leaves (3.51mg/g and 1.79mg/g respectively) and significantly decreased (P<0.05) with leaf maturity. The mature and old tea leaves were found to possess high amounts of EGC, and so may be utilized for further applications.
| Item Type: | Academic Exercise |
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| Keyword: | Determination of selected polyphenols, Cameron tea leaves of different maturity, Crude protein, Crude fat, Crude fibre, Ash content, Carbohydrate content |
| Subjects: | Q Science > QK Botany > QK1-989 Botany > QK710-899 Plant physiology |
| Department: | SCHOOL > School of Food Science and Nutrition |
| Depositing User: | ADMIN ADMIN |
| Date Deposited: | 07 Jun 2012 18:37 |
| Last Modified: | 23 Oct 2017 11:46 |
| URI: | https://eprints.ums.edu.my/id/eprint/4209 |
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