Numerical study of the thermolysis of catechins in green tea

Abstract

AbstractTea contains health benefits due to its compounds such as catechins, which undergo thermolysis during heating. These complex reactions have been proposed as first order kinetic models at controlled conditions, and this work proposes a non‐first‐order kinetic model to cover a wide range of conditions. Afterward, these reactions were simulated via computational fluid dynamics in order to determine the concentration at different operative conditions. The system was a continuous heating reactor, where mesh and iteration tests were developed. The results indicated that the reactions presented a high thermal dependency, and a short residence time with low conversion due to the low values of the Damköhler number. Thus, the kinetic model proposed herein reached a well representation of the thermolysis of catechins, which suggests the applicability of this model and strategy in other thermal treatments of tea.Practical ApplicationThe high comsumption of green tea demands better process treatments in order to reduce the perishable compounds. Thermal processing of tea requires a thorough understanding of thermolysis in catechins. The basis of this paper can be extended into evaporation and drying of green tea under CFD simulation.