investigation of mass transfer diffusivity dependency in drying process of lemon

Achieving the rate and the amount of mass transfer is of paramount importance in selecting optimum conditions for drying and affects the development of the quality of drying. note that, to obtain the amount of mass transfer, the conditions of mass transfer such as temperature, pressure, geometry, and diffusion coefficient should be completely determined. in this research, an experiment is conducted in atmospheric conditions and then the amount of mass flow in a spherical body is measured. utilizing the newman equation and the experimental results, the diffusion coefficient is found to be in the range of 10^-11 m^2/s. additionally, the experimental data reveal the linear and exponential variation of diffusion coefficient with a constant coefficient of 1306.8 and exponent of 2.0883 which is against size and time.