A multiple regression approach to the combined microwave and air drying process Original Research Article

A semi-empirical approach was used to develop mathematical models to evaluate the performance of various combinations of microwave power and air conditions during the drying of Solanum tuberosum (potatoes). An experimental system was developed whereby air was introduced into the cavity of a domestic microwave oven. A multiple linear regression technique was employed to relate the drying rate constant to the design and operational parameters, which included air temperature, air velocity and microwave power as well as sample specifications. This allows the models to take into account the microwave characteristics as well as the surrounding air effects. The modelling equations verified the experimental results and proved to be an important tool in predicting the drying rate under any drying conditions. The models indicated that microwave power levels and sample specifications are the most important parameters, with statistically significant effects on the drying constants. Air temperature and velocity were of less significance within the range considered in this study.