Development of a Method to Estimate Moisture Diffusivity as a Function of Local Moisture Content for the Numerical Simulation of Food Drying Process

Abstract

A method to estimate the moisture diffusivity (D_m) of fish-sausage is given as a function of local moisture content. The correlation of the moisture diffusivity is determined by matching the time history of the numerically estimated average moisture content and that obtained from an experiment. The simulation is based on a semi-two dimensional heat and mass transfer analysis with shrinkage and variable thermal properties. The data of the sausage's properties and its shrinkage during the course of drying are obtained from the experiment. The drying air conditions are 50±2^oC of temperature and 0.67±0.02 m/s of velocity with 5.1-6.2% of RH. The size of the specimen is approximately 70, 100 and 10 mm of width, length and thickness, respectively. The calculated result of the drying curve using obtained D_{m, local} gives an error less than ±1.5%.