Physicochemical Properties of ‘Cisalak’ Robusta Coffee With Hot Air Based Roasting Method

Abstract

The roasting technique is considered one of the coffee processing stages that can continue to be developed for sustainable innovation, both in the process and in the equipment. It is an important factor that determines the coffee’s quality. This study aimed to assess the impact of the roasting method using a hot air roaster on the physicochemical properties of Cisalak robusta coffee. The method for roasting green coffee beans was conducted under six conditions based on the speed and level of roasting: slow-light, slow-medium, slow-dark, fast-light, fast-medium, and fast-dark. The bulk density, hardness of coffee beans, water content and lightness of coffee powder decreased as the roasting level increased, whereas the ash content, pH level and caffeine content increased. The slow roasting speed produced a coffee with a lower water content and hardness, whereas the ash content, L values and pH level was higher than fast roasting method. Based on the results, robusta coffee which was roasted using various methods in this study had a range 0.309-0.357 g/ml of bulk density, 5932.99-7164.87 gf of hardness, 34.44-39.98 of lightness, 0.8073-1.5556 % of water content, 4.8010-5.3643 % of ash content, 5.62-6.23 of pH level and 0.96-1.36% of caffeine content.

Keywords

• coffee roasting
• physicochemical properties
• hot air roaster
• cisalak robusta coffee
• sustainable innovation