MATHEMATICAL MODELS OF SWEET BASIL (OCIMUM BASILICUM LINN.) DURING MICROWAVE DRYING

The drying characteristics of sweet basil in microwave drying at 335, 400 and 545 W were determined and the applicability of different drying models was investigated in order to find the product’s moisture ratio at any time of the drying process.
The time required to reduce the moisture content of sweet basil from 5.23±0.82 to 0.064±0.005 g_water/g_{dry matter} were 241, 335 and 462 s, respectively.
To evaluate the drying kinetics, the obtained experimental data was applied to three mathematical models (Newton, Page and Logarithmic) and the model with the best fit was determined.
The results showed that the Page model could describe the drying characteristics at the most satisfactory level because it gave the highest coefficient of determination (0.9987-0.9998), the least chi-square (0.71×10^-4-4.82×10^-4), and the lowest root mean square error (0.0079-0.0191). Effective moisture diffusivities were determined to be 3.6×10-10, 5.1×10^-10 and 5.9×10^-10 m² s^-1 respectively.
The activation energy was calculated using an exponential expression based on Arrhenius equation.
The relationship between the drying rate constant and effective moisture diffusivity was also estimated and showed a linear relationship.

II Southeast Asia Symposium on Quality Management in Postharvest Systems

R. Assawarachan, K. Kalayanamitra

sweet basil, microwave drying, semi-empirical model

https://doi.org/10.17660/ActaHortic.2015.1088.113