Convective dehydration kinetics of noodles prepared from taro (Colocasia esculenta), rice (Oryza sativa) and pigeonpea (Cajanus cajan) flours

Abstract

Drying characteristics of noodles prepared from 50% taro and remaining equal proportions of rice and pigeonpea flours were investigated in a convective type dryer for a temperature range of 50°C to 80°C at a constant air velocity of     1.5 m s^-1.  Results indicated that drying took place in falling rate period.  The sample dried at 50°C was found better in color as compared to samples at 60°C, 70°C and 80°C.  The rehydration weight of noodles decreased with the increase in drying temperature.  Moisture transfer from noodles was described by applying Fick’s diffusion model and the effective moisture diffusivity was calculated.  Effective moisture diffusivity increased with increase in temperature.  An Arrhenius relation with activation energy of 38.53 kJ mol^-1 expressed the effect of temperature on moisture diffusivity.  Mathematical models were fitted to the experimental data and the performance of these models were evaluated by comparing the coefficient of determination (R²), Root mean square error (RMSE), reduced chi-square (χ²), percent mean relative deviation modulus (E%) between observed and predicted moisture ratio.  Verma model gave the best results for describing the drying behaviour of noodles.

Keywords: noodle, taro, dehydration kinetics, temperature, moisture