Mathematical modeling of tea bag infusion kinetics

Abstract

The current work explains the development of a mathematical model for the prediction of tea bag infusion kinetics of solid-liquid extraction of polyphenols from tea. The developed model has been used to obtain tea bag infusion profile using equilibrium parameters i.e. partition constant (K), the initial content of tea solute (Csi) and tea bed permeability (κ). The Predicted infusion profiles and experimental data are in good agreement having mean relative error <10%. For all the conditions (loading in the tea bag, particle size, temperature, and dipping frequency), the Gallic acid equivalence (GAE) per unit equilibrium concentration (Cveq) eluted inside tea bag (Cbˆ) was found to be higher as compared to that in the vessel (Cvˆ). The increased loading and increase in particle size for given loading exhibit slower infusion kinetics. However, an increase in dipping frequency (Reynolds number) and temperature leads to an increase in mass transfer coefficient leading to faster infusion kinetics.