Karakterisasi mutu fisikokimia dan sensorik kopi bubuk arabika dan robusta berdasarkan tingkat roasting

Abstract

The roasting level is a primary factor determining the physicochemical and sensory quality of ground coffee. This study aimed to investigate the influence of roasting levels on the physicochemical and sensory characteristics of Arabica ground coffee—with Robusta coffee as a comparison—and to determine the optimal treatment using the De Garmo effectiveness index method. A factorial Completely Randomized Design (CRD) was employed, with coffee variety (Arabica and Robusta) and roasting level (Light Roast/R1, Medium Roast/R2, and Dark Roast/R3) as factors, each performed in triplicate. Observed parameters included moisture content, ash content, pH, caffeine content, fat content, antioxidant activity, color (L*, a*, b*), and organoleptic properties (taste, color, aroma, and texture). Physicochemical data were analyzed using One-Way ANOVA followed by a Tukey test at a 95% confidence level, while sensory data were analyzed using the Friedman test. The results indicate that the roasting level significantly affects most physicochemical and sensory parameters for both Arabica and Robusta ground coffee. Increasing the roasting level reduces moisture content and lightness (L*), while also influencing ash content, pH, caffeine content, fat content, antioxidant activity, and the color values a* and b*. Organoleptic evaluations reveal that panelists generally preferred coffee with higher roasting levels in terms of taste, color, and aroma. Based on the De Garmo effectiveness index analysis, the optimal treatment for Arabica ground coffee was the Light Roast (effectiveness index of 1.0994), whereas for Robusta ground coffee, it was the Medium Roast (effectiveness index of 1.1333), demonstrating that the optimal roasting level varies between coffee varieties.