The general objective of this study was the evaluation of a system for coffee drying, using partial drying in fixed bed dryer and complementary drying in an intermittent concurrent flow batch dryer. The experiment was carried out in the Vegetable Products Processing Area, DEA-UFV. The drying tests were accomplished in completely randomized design. The coffee was harvested on the ground by manual striping process. The fruits were pre-processed by drying of ripe, overripe and greenish cherries. For the preliminary drying, the initial coffee moisture content varied from 68.9 to 71.3% w.b. with the drying being interrupted with moisture content between 44.0 and 47.5% w.b. In the complementary drying phase the final moisture varied between 12.2 and 13.8% w.b. The temperature of the drying air, in the fixed-bed dryer, varied from 50.4 to 76 °C, and in the concurrent flow batch dryer, between 87.2 and 110 °C. The specific enthalpies were 8.4 to 9.1 MJ kg-1 and 7.1 to 16,9 MJ kg-1 for the fixed-bed dryer and concurrent flow batch dryer, respectively. In comparison with the control tests, the final quality of the product presented better commercial characteristics. It was concluded that with preliminary drying in fixed bed dryer and complementary drying in a concurrent flow dryer, besides reducing the total drying time, the combined system contributes to a better preservation of qualities acquired in field.
energy; fixed-bed; concurrent flows; coffee quality
