Changes Of Some Engineering Properties Of Coffee Beans Due To Roasting Process

The changes in physical, mechanical, and colours after roasting in two-level were investigated. Aims
of this study were to evaluate changes in the physical, mechanical, and colours due to the roasting process of the
Arabica and Robusta coffee bean grown in Cisalak Sub-District, Subang District-West Java. Results of analysis
determined that the roasting process resulted in decreasing the moisture content of green coffee bean from 13.8% to
6,54% of first-level roasted bean and 6.24 of the second-level roasted bean, while that of robusta decreased from
11.22% to 7.56 and 6.12%. First-level roasting was categorised as a light roast, while the second-level was a medium
roast. The Roast Weight Loss of arabica and robusta from green to light roast bean were 19.45 % and 16,24%,
respectively, and that to medium roast bean was 26.20% and 22.37%, respectively. The roast volume change of
arabica and robusta from green to light roast bean were 50.55% and 44.30 % respectively, and that to medium roast
bean were 54.65% and 55.92 % respectively. The total colour differences between green with light and medium roast
bean of arabica were 6.39 and 2.52, while that of robusta were 6.19 and 2.49, respectively.