Physicochemical properties of robusta coffee during roasting temperature and time degradation

Coffee has excellent bioactive compounds which have a positive effect on improving human health. Among the process of coffee, roasting has a pivotal role in the maintenance of the bioactive compounds of coffee. Hence, coffee should be roasted at an appropriate temperature and time. This study aimed to determine coffee’s physicochemical properties during changes in roasting temperature and roasting time. This research was conducted with two treatments. There were fixed temperatures (with various times) and varied temperatures (with fixed times). In the first treatment, robusta coffee was roasted at 180°C, 190°C, and 220°C for 7 minutes, and the second was roasted at 200°C for 4, 6, and 8 minutes. The research was designed to use a completely randomized 2 factor with three replications. The variables observed were weight loss, pH, total dissolved solids (TDS), color intensity (L*, a*, b*), moisture content, ash content, and antioxidant capacity. The increased roasting temperature and roasting time decreased L*, a*, b*, moisture content, and antioxidant capacity. Meanwhile, the weight loss, pH, and ash content increased due to the increase in temperature and time. The difference between roasting temperature and roasting time had changed antioxidant capacity from 82.51% (180°C) to 62.31(190°C) and from 83.32% (6 min) to 46.57% (8 min), respectively.