Journal of Food Engineering, Vol.263, 38-45, 2019
Drying kinetics, quality and moisture diffusivity of spouted bed dried Sri Lankan black pepper
Drying of black pepper has been investigated in a lab-scale conventional spouted bed dryer. Spouting behavior of black pepper was studied, and the minimum spouting velocity was determined. The effect of operational conditions; drying temperature, air velocity and stagnant bed height on drying kinetics was analysed. The higher values of drying rates were achieved when the dryer was operated with moderately high temperatures, high airflow rates and shallow beds. The results show an increase in effective moisture diffusivity with increasing drying temperature. The highest effective moisture diffusivity of 2.03 x 10(-10) m(2)/s was obtained at a hot air temperature of 75 degrees C. Extraction and analysis of essential oil from dried black pepper showed that the variation of oil yield with drying temperature is significant for drying temperatures from 45 degrees C to 75 degrees C 65 degrees C was selected as the best drying temperature for black pepper drying in the conventional spouted bed dryer.
Keywords:Spouted bed dryer;Black pepper;Black pepper essential oil;Drying kinetics;Moisture diffusivity