title: New Sample Preparation Method for Quantification of Phenolic Compounds of Tea (Camellia sinensis L. Kuntze): A Polyphenol Rich Plant.
abstract: Chemical analysis of the Sri Lankan tea (Camellia sinensis, L.) germplasm would immensely contribute to the success of the tea breeding programme. However, the polyphenols, particularly catechins (flavan-3-ols), are readily prone to oxidation in the conventional method of sample preparation. Therefore, optimization of the present sample preparation methodology for the profiling of metabolites is much important. Two sample preparation methodologies were compared, fresh leaves (as in the conventional procedures) and freeze-dried leaves (a new procedure), for quantification of major metabolites by employing two cultivars, one is known to be high quality black tea and the other low quality black tea. The amounts of major metabolites such as catechins, caffeine, gallic acid, and theobromine, recorded in the new sampling procedure via freeze-dried leaves, were significantly higher than those recorded in the conventional sample preparation procedure. Additionally new method required less amount of leaf sample for analysis of major metabolites and facilitates storage of samples until analysis. The freeze-dried method would be useful for high throughput analysis of large number of samples in shorter period without chemical deterioration starting from the point of harvest until usage. Hence, this method is more suitable for metabolite profiling of tea as well as other phenol rich plants.
authors.affiliation: Institute of Biochemistry Molecular Biology and Biotechnology, University of Colombo, 00300 Colombo, Sri Lanka.
authors.forename: P A Nimal
authors.initials: PA
authors.lastname: Punyasiri
authors.affiliation: Department of Food Science and Technology, Faculty of Agriculture, University of Peradeniya, 20400 Peradeniya, Sri Lanka.
authors.forename: Brasathe
authors.initials: B
authors.lastname: Jeganathan
authors.affiliation: Tea Research Institute of Sri Lanka, 22100 Talawakelle, Sri Lanka.
authors.forename: Jeevan
authors.initials: J
authors.lastname: Dananjaya Kottawa-Arachchi
authors.affiliation: Tea Research Institute of Sri Lanka, 22100 Talawakelle, Sri Lanka.
authors.forename: Mahasen A B
authors.initials: MA
authors.lastname: Ranatunga
authors.affiliation: Tea Research Institute of Sri Lanka, 22100 Talawakelle, Sri Lanka.
authors.forename: I Sarath B
authors.initials: IS
authors.lastname: Abeysinghe
authors.affiliation: Coordinating Secretariat for Science, Technology & Innovation, 3rd Floor, Standard Charted Building, Janadhipathi Mawatha, 00100 Colombo, Sri Lanka.
authors.forename: M T Kumudini
authors.initials: MT
authors.lastname: Gunasekare
authors.affiliation: Department of Chemistry, Faculty of Science, University of Peradeniya, 20400 Peradeniya, Sri Lanka.
authors.forename: B M Rathnayake
authors.initials: BM
authors.lastname: Bandara