HYDRODYNAMICS STUDY OF COFFEE BEANS (Coffea arabica L.) ROASTED IN FLUIDIZED BED
In this work, the hydrodynamics of fluidization of green and roasted coffee beans was studied at three different levels of temperature, processing time and superficial air velocity Uo. Also, the effect of these variables on color, weight loss, moisture content, bulk density, increase in volume and equivalent diameter of the coffee bean were studied. Green coffee beans Typical var. was applied as testing material. A factorial design 23 was used, adding a central point to determine the effect of independent variables on hydrodynamics parameters. Low level, central point and high levels values were 220, 230 and 240oC for air temperature; 5, 7.5 and 10 minutes for processing times and 3, 3.5 and 4 m/s for Uo. Results showed that temperature and processing time had a significant effect (p<0.05) on color of the bean, loss of weight, moisture content, bulk density and increase in volume of grain. Time-temperature and time-air velocity combination also had significant effect on loss of weight and on the increase of grain volume.
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