INVESTIGATING ON EFFECT OF HOT AIR AND WATER TEMPERATURE ON KINETIC OF REHYDRATION OF CELERY BY USING PELEG’S MODEL

Abstract

The Peleg model was used to determine effect of drying conditions and rehydration water temperature on kinetic of moisture content and rehydration ration changes of celery. Celery cubes (1×1×1 cm) were dried at 65ºC in hot air oven. Samples were rehydrated by immersion in water during different periods of time and temperatures (25±2ºC and 100±2ºC). Rehydration kinetic was monitored by measuring samples' weights at regular intervals. Results showed that the highest final moisture content which was observed belonged to the samples which were dried at 70 °C and reydrated at 25°C water temperature, also, dried celeries which were rehydrated at a water temperature of 25°C, had higher levels of RR as a function of physical properties. The Peleg’s e constant (K1), decreased significantly while water temperature increased and in case of the Peleg capacity constant (K2), it increased slightly while water temperature increased. Decreasing of K2 values is a sign of more water absorption capacity. Finally, it was observed that the predicted and experimental values had a good correlation which indicates that the Peleg model is adequate to describe rehydration kinetics of celery cubes.