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Microwave effect on drying behavior and quality parameters of green tea leaves

Mert Köse, Haydar Küçük, Adnan Midilli


This study aims to investigate the effect of microwave on drying behavior and quality parameters of green tea leaves experimentally and to perform mathematical modeling of microwave drying of green tea leaves. For this purpose, experiments were performed at 100 W, 300 W, 600 W and 800 W microwave powers and the mass loss and drying time were measured. Depending on the measured parameters, dimensionless moisture ratio, moisture content, mass shrinkage ratio, and drying rate were estimated. The quality parameters such as water extract, cellulose, total ash, caffeine, and total polyphenol were also determined. Furthermore, the best thin layer drying curve equation was obtained by using mathematical modeling for microwave drying of green tea leaves. As a result, improved Midilli-Kucuk model was determined as the best drying curve equation that describes the drying behavior of green tea leaves at all microwave power levels adopted. Also, it was determined that the highest water extract is 35.44% at 300 W, the highest caffeine is 1.93% at 800 W, the highest polyphenol is 11.20% at 300 W, the lowest total ash is 5.95% at 800 W, and the lowest cellulose is 17.79% at 300 W. It was observed that green tea leaves retain their natural color in its best at 800 W.  

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