Dehydration is the one of the simplest ways to improve the shelf-life of fruits and vegetables by reducing the moisture content. Dehydration operations are important steps in food processing industry, which involves a process of moisture removal due to simultaneous heat and mass transfer. Drying provides a longer shelf-life to the food, cheaper transportation cost, and smaller space demand during storage. Hot-air drying of hamcho pieces were carried out to compare the influence of blanching at 90℃ for 5 min as a pre-treatment on the drying kinetics at temperatures of 50℃, 60℃, and 80℃ at a constant airflow velocity of 0.66 m/s. The pretreatment had significant effects on the moisture content of the hamcho samples. In all the drying temperature selected, the blanched samples had shorter drying time than the control. Based on these comparisons it is seen that blanching treatment prior to drying could improve the drying kinetics of hamcho samples at all drying temperatures. The activation energy was calculated by plotting the natural logarithm of drying rate constant (k) versus the reciprocal of the absolute temperature. It turned out to be 36.90 and 30.76 kJ/mol for the control and blanched sample, respectively.

• Jun Ho Lee(Department of Food Engineering, Daegu University)