Abstract

The hot air drying characteristics of celery root were evaluated in a laboratory scale dryer at the drying temperatures of 50, 60, 70 and 80°C. The effect of hot air drying on drying time, drying rate, moisture content, moisture ratio and effective moisture diffusivity of celery root was investigated. Fifteen thin layer drying models were fitted by using experimental drying data. The fitting effect of model predictions was evaluated by using the values of coefficient of determination, sum squared error, root mean square error and chi-square. The results showed fitting accuracy of model 15 (Hii et al., 2009) gave a better fit for all drying conditions applied. The average values of effective moisture diffusivities of celery root ranged from 1.957×10^-9 to 9.016×10^-9 within the given drying temperature range. With in a certain temperature range (50-70°C), the average effective moisture diffusivities of celery root increased with increased temperature. The activation energy was estimated as 21.817 KJ/mol using an exponential expression based on the Arrhenius equation.

Keywords:

Activation energy, celery root, effective moisture diffusivity, hot air drying, thin layer drying models,

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