| dc.description.abstract | Drying method is an important process in determining the quality of coffee beans. Traditional drying methods have constraints such as the low efficiency of solar intensity, the presence of dust and dirt contamination, thus affecting the quality of the final product of coffee beans. The solar energy drying method using a drying room is a solution in maintaining the quality of coffee beans from contamination. In addition, the drying speed and temperature of the drying room have a very large role in determining the quality of coffee beans. The speed of airflow into the drying chamber (forced convection) is proven to increase the drying speed of coffee beans. However, the determination of the proper drying speed and drying temperature for coffee bean quality has not been explained in more detail. So in this study, the design of 5 (five) solar dryer units with different airflow speeds and testing were carried out with the aim of obtaining drying speed and drying temperature to produce quality coffee bean drying quality such as moisture content according to SNI standards and protein content, carbohydrate content, and free fatty acids. The solar energy dryer system with a forced convection system designed is to use solar energy then convert it into heat energy using a solar collector, the heat energy will heat the air in the solar collector then forced to flow using a fan to enter the drying room. Variations of air velocity into the solar energy drying chamber include 1.0 m/s; 1.5 m/s; 2.0 m/s; 2.5 m/s; and 3.0 m/s. The initial mass of coffee beans is 1500gram and the initial moisture content is 65%. Testing of the five solar energy drying units was carried out simultaneously and the drying process was stopped when one of the solar energy drying units reached a moisture content of 12% coffee beans according to SNI standards. The final results showed from 5 units of solar energy dryers with forced convection that the final moisture content in the dryer tool 1 (BD1) was 12%, tool 2 (BD2) was 13.6%, tool 3 (BD3) was 18.5%, tool 4 (BD4) was 12.9%, and tool 5 (BD5) was 15.2%. The drying process to reach a moisture content of 12% requires a drying time of 27 hours. The average drying temperature in the drying chamber of tool 1 (BD1) was 41.10C, tool 2 (BD2) was 42.60C, tool 3 (BD3) was 40.60C, tool 4 (BD4) was 40.20C, and tool 5 (BD5) was 400C. Protein content in tool 1 (BD1) was 11.7%, tool 2 (BD2) was 12.2%, tool 3 (BD3) was 11.5%, tool 4 (BD4) was 11.6% and tool 5 (BD5) was
11.3%. Carbohydrate content in tool 1 (BD1) 21.7%, tool 2 (BD2) 22.8%, tool 3 (BD3) 19.9%, tool
4 (BD4) 18.1% and tool 5 (BD5) 20.4%. Free Fatty Acid content in tool 1 (BD1) 0.05%, tool 2
(BD2) 0.05%, tool 3 (BD3) 0.09%, tool 4 (BD4) 0.09% and tool 5 (BD5) 0.08%. In this study, it was found that the drying speed and drying temperature with quality coffee beans according to SNI standards were found in dryer 1 (BD1), namely the drying speed of coffee beans of 27 hours where the solar radiation that still exists in one day is 10 hours, and on the third day the decrease in coffee mass in tool 1 has reached a balanced weight or 12% moisture content and the average temperature in the drying room is 41.10C. In addition, based on calculations, the efficiency of the tool 1 dryer collector (BD1) is 46%. | en_US |
