Experimental study and mathematical modelling of convective thin-layer drying of noni (Morinda citrifolia L.)

Abstract

In this study, the drying kinetics of noni (Morinda citrifolia L.) was investigated in a laboratory tunnel dryer at air temperatures of 50, 60, and 70 °C and velocities of 1.0, 1.5, and 2.0 m/s. Noni showed only a falling drying rate period. Further, a non-linear regression procedure was used to determine the characteristic drying curve. The experimental drying data of noni were employed to fit thin-layer models. Under the evaluated experimental conditions, the Page model provided the best representation of thin-layer drying characteristics of noni. The effective moisture diffusivity ranged from 1.77 × 10-7 to 3.33 × 10-7 m2/s. The activation energy was found to be 3.34 kJ/mol.