Abstract
Extraction is an experimental method wildly used in chemical analysis, but there are relatively few kinetic researches. In 2014, S. Lee, B.D. Hsu and S.M. Hung published” modelling of isothermal chloro-phyll extraction from herbaceous plants”. This model established a mathematical model to describe the kinetics of chlorophyll extraction, and had a success on herbaceous plants. In this study, we try to use this model on Camellia sinensis, which is a more complex plant, and both fresh leaves and dried leaves had been tested. We also extract caffeine, which is extracted by DI water in this study, to distinguish DI water from organic solvents. Furthermore, creep test had been accomplished to study the mechanic properties of fresh leaf, and contact angle had been executed to study surface energies of fresh and dried leaf. Finally, this model have good prediction on each condition mentioned above, and we got the diffusion coefficient, wetting time and relaxation time from extraction model. We discover that chlorophyll extraction in fresh leaves is much easier than dried leaves, but caffeine extraction is not. Rate of chlorophyll extraction depends on the polarity of solvents. The model has the potential on decaffeination and catechins extraction of tea leaf in the future.