The Kinetic Study of Dampit Robusta Coffee Caffeine Degradation by Saccharomyces cerevisiae

About 2–2.8% of robusta coffee contains caffeine. The maximum caffeine content in coffee should be between 0.45–2% according to the standard. Consequently, the fermentation process is required to lower the caffeine content in robusta coffee. Saccharomyces cerevisiae produces enzymes during fermentation process that can break down caffeine into uric acid, 7-methylxanthine, and xanthine. In this study, simulation is used to obtain data on fermentation’s kinetics. The goal of this study is to determine the effect of Dampit robusta coffee fermentation using S. cerevisiae on the caffeine level in coffee beans and to simulate the fermentation process using the Monod equation. This study employs two techniques: laboratory-scale investigation and simulation of fermentation kinetics. Ultraviolet-visible spectrophotometry is used to analyze the caffeine content. The caffeinelevel data is used in fermentation kinetic simulation using microsoft Excel software. Simulation data is validated using the coefficient of determination (R2) on the regression results and the least significant difference method. Caffeine-level data is tested with 24, 36, 48, 60, and 72 h as the fermentation time variables. The study’s findings indicate that fermentation using S. cerevisiae can reduce caffeine content to 15.0063 mg/g. Simulation of robusta coffee fermentation using the Monod equation yields the valid values of reaction rate constant (k) and Monod constant (CM) as −0.01047 and −24.978, respectively. Monod fermentation is suitable for simulating the fermentation of Dampit robusta coffee using S. cerevisiae with a fermentation time of 24–60 h.