Modeling of Tea Infusion Kinetics Incorporating Swelling Kinetics

Abstract

Abstract Mathematical model to predict tea infusion kinetics which accounts for swelling kinetics of tea granules is presented. Swelling kinetics of tea granules has never been taken into account for models developed so far. Differential equations (DEs) for concentration of tea constituents inside tea granule with respect to radius and time were derived. Solution methodology for these DEs is developed based on Crank-Nicholson scheme. Tea infusion profile is obtained using this model by knowing the swelling kinetics, partition constant and initial contents in tea granules. Diffusivity and product of interfacial area (As) and backward rate constant (k−1) are the fitting parameters. Model prediction is fitted to the experimental data published previously (R2 = 0.90–0.98). The fitted diffusivity (3.33 × 10−10 m2/s) and Ask−1 (2 m3/(kg.s)) predicted the infusion profile of other sized tea granules very well. This model predicts the infusion during initial stage very accurately without any empirical parameter.