MODELING AND OPTIMIZATION OF MICROWAVE DRYING OF TURMERIC SLICES
This study was conducted to evaluate the effects of microwave power at 164, 465 and 752 W on the quality of turmeric slices and determine the suitable drying model that can predict the products moisture ratio at any time of the drying process. Dried product quality was measured based on color changes using L*, a and b*. Color quality changes of dried turmeric slices were highest at 752 W quantified by L* and b* values; in contrast, a* value and total color difference (TCD) did not significantly differ with microwave power. Results were successfully determined by the Box-Behnkens response surface methodology. The experimental data were fitted to three thin layer drying models (Newton, Page and Logarithmic). The Page and Modified Page model were found as good models to predict the drying behavior of turmeric slices. The Page model was however the most satisfactory giving the highest coefficient of determination (0.9987-0.9993) and lowest chi-square (0.7×10-4-2.61×10-4) and root mean square error (0.0079-0.0142). Using the model, the optimum drying conditions that gave the lowest total color difference of 3.44 were 443.93 W microwave power with 5.1% ascorbic acid and 55.6 s drying time.
Assawarachan, R., Kalayanamitra , K. and Keokamnerd, T. (2015). MODELING AND OPTIMIZATION OF MICROWAVE DRYING OF TURMERIC SLICES. Acta Hortic. 1088, 599-604
Curcuma longa, color quality, Box-Behnken response surface methodology