Modelling mass transfer characteristics in microwave drying of potatoes

In microwave drying, removal of moisture is accelerated and heat transfer to the solid is slowed down significantly due to absence of convection. In a microwave dying system, quick energy absorption causes rapid evaporation of water and creates an outward flux of escaping vapor. There are several experimental and theoretical studies on transport phenomena in food industry, however, there is lake of clear and transparent works on some of foods, particularly in Iran. This paper presents some results of a work is being undertaken at university of Guilan. It describes some mass transfer characteristics such as moisture diffusivity and moisture transfer coefficient of slab and cylindrical potato samples by using an analytical model. A microwave system with different output powers was used to dehydrate potato samples with different diameters and lengths. The moisture content and moisture ratio of the sample were measured and using collected data drying coefficients and lag factors were calculated and incorporated into the model. Effects of microwave power and samples’ dimensions on drying characteristics were investigated.

کلیدواژه ها:

Microwave drying ، Analytical model ، Moisture diffusivity ، Potato