Infrared drying of food products

The aim of this work was to study the infrared (IR) drying of food products. In present article the effects of blanching, of air velocity and of different air temperatures on the drying time and on the rehydration ratio as a quality property are investigated. During research different food materials were used: apple, carrot and potato. In the article a simultaneous heat and mass transfer model is presented that calculates the rate of moisture vaporization with the approximation less than 10 % for 20-30 min of the 1st period of the drying process. The food materials slices were dried by near infrared (NIR) heating by the natural, and by the forced convections with air velocities 0.25 and 0.5 m/s and at different air temperatures 23 and 28 oC. NIR drying should give good results for dehydration of thick materials that is needed for better preservation of food quality. The qualities of dried slices were compared by a rehydration ratio.