Small-scale Demucilager Machine for Arabica Coffee (Coffea arabica)

Abstract

Natural fermentation is time- and water-consuming, laborious, and causes weight loss in the coffee beans. It is the conventional method to remove coffee mucilage in the Philippines that can take up to 48 hours. This study aimed to develop a small-scale demucilager machine and evaluate its demucilaging capacity, demucilaging efficiency, product recovery, damaged parchment coffee, and electrical power consumption. It also aimed to compare the use of the demucilaging machine and the natural fermentation in terms of processing time, human labor, and water consumption. The developed demucilaging machine is a continuously-fed horizontal machine that separates mucilage from the parchment coffee by abrasion. It consisted of the following components: the hopper, which receives the freshly depupled parchment coffee: the demucilaging cylinders, which separate the mucilage to the parchment coffee: the water supply system that delivers water to the hopper and the demucilaging cylinders: the output chute, that discharges the parchment coffee: the power transmission system, transmit power from the electric motor to the machine: and, the frame, that holds other components in place. Evaluation results showed that the machine has a 37.87 kg/hr capacity, 79.0% demucilaging efficiency, 4.87% parchment coffee damage, 96.96% product recovery, and 41.54 W-hr electrical energy consumption at 1.23m/s peripheral speed and 0o inclination. It also reduced processing time from 12-24 hours using natural fermentation to 2.64 hours using the machine. Human labor was also reduced from 4 in natural fermentation to 2 operators using the machine. Water consumption from natural fermentation to machine use is 0.87-1.60 L/kg to 0.22 L/kg, respectively. Lastly, the use of the machine is economically feasible at a custom rate of 1.75 Php/kg with a break-even weight of 11,517.00 kg/yr. The payback period of the machine is 2.49 years with a benefit-cost ratio of 0.62.