Yen, Catherine Shiuk Ting (2008) Polyphenol and flavonoid contents, antioxidative property and nutritional values of Sabah Tea (Camellia Sinensis). Universiti Malaysia Sabah. (Unpublished)
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Abstract
There were twelve types of extracts (T01 - T12) prepared from tea samples (Camellia sinensis) collected from Sabah Tea Plantation which were evaluated for their total polyphenol and flavonoid contents and antioxidative activity. The total polyphenols, as analyzed using the Folin-Ciocalteu method, varied from 410 mg GAE/g to 2138 mg GAE/g in the tea extracts. TOI and T08 (young tea leaves extracts) contained extremely high phenolic compounds (2138 mg GAE/g and 1246 mg GAE/g, respectively) with potent inhibition of free radicals (94% and 77%, respectively at 0.02 mg/mL) in DPPH assay . All the tea extracts showed stronger antioxidative potential compared to BHT (butylated hyroxytoluene, a synthetic antioxidant). T11 and T12 (processed BOPF and Dust tea extracts) contained the highest flavonoids content (29.88 - 35.13 mg QE/g) among all the tea extracts. Seven of the potent antioxidation tea extracts were selected to undergo nutritional values (lipid, caffeine, protein, minerals and phosphorus) determination. The lipid content ranged from 0.5 - 2.25%. T03 (organic open-air young tea leaves extract) showed the highest lipid content while T08 (conventional open-air young tea leaves extract) showed the lowest. T01 and T03 (organic young tea leaves extracts) contained the highest content of caffeine, 8.87% and 13 .05%, respectively using UV analysis and 14.31 % and 18.55%, respectively using HPLC analysis. Whereas, T02 and T09 (old tea leaves extract) showed the lowest caffeine content. Sodium was the major mineral while copper and zinc were the minor minerals in all the extracts. T03 contained the highest content of all the minerals (2.318 mg Na, 0.042 mg Cu, 0.053 mg Ca, 0.123 mg Fe, 0.028 mg Zn, and 0.766 mg P per gram of tea extract). Moreover, T11 and T12 showed moderate contents in all nutritional tests. In conclusion, organic shaded young tea leaves extract (T01) is the best tea extract to develop as a nutraceutical product due to the highest contents of polyphenols, antioxdative properties and some minerals content. It is also free from pesticide and thus healthier compared to other tea extracts.
| Item Type: | Academic Exercise |
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| Keyword: | Camellia sinensis, Sabah Tea Plantation, polyphenol, flavonoid content, antioxidative activity, tea extract, nutraceutical product |
| Subjects: | Q Science > QD Chemistry T Technology > TX Home economics > TX1-1110 Home economics > TX341-641 Nutrition. Foods and food supply |
| Department: | SCHOOL > School of Science and Technology |
| Depositing User: | SITI AZIZAH BINTI IDRIS - |
| Date Deposited: | 20 Feb 2014 11:22 |
| Last Modified: | 12 Oct 2017 08:10 |
| URI: | https://eprints.ums.edu.my/id/eprint/8243 |
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