Finite Element Modeling of Freezing of Coffee Solution

C. Anandharamakrishnan, R. Gopirajah, and N. Chhanwal
Central Food Technological Research Institute
Mysore
Karnataka, India

Freeze-drying is a popular method of producing shelf stable particulate products and is of particular value for drying thermally sensitive materials (volatiles and biological based), which can be heat damaged by higher temperature methods, such as spray-drying. Porous structures are formed by the creation of ice crystals during the freezing stage, which subsequently sublime during the drying stage and this often leads to good rehydration behaviour of the powdered product .

In this study, a finite element model was developed to describe the dynamic behavior of the primary and secondary stages of the freeze-drying of coffee solution using COMSOL. The model predictions were validated with the experimental measurements of temperature. This developed model predicts the temperature, partial pressure of water vapour and concentration of sorbed water with respect to time.