Drying and rehydration characteristics of water chestnut (Trapa natans) as a function of drying air temperature

Drying characteristics of water chestnut were evaluated in a commercially available cabinet oven at different air temperatures (50, 60, 70, 80 and 90 °C) to compare the drying rate and to analyze the effect of different drying air temperature on rehydration properties. The product dried at 70 °C had better rehydration characteristics. The rate constants of the exponential and Page’s model for thin-layer drying were established by regression analysis of the experimental data which were found to be affected by drying air temperature. The rate constant (k) increased (0.254–0.940 h−1) with the drying air temperature. The ΔE value decreased while increasing the temperature with the values varied from 91.17 to 89.66. Rehydration characteristics were significantly affected by the drying air temperature and found to decrease with increase in drying air temperature.