Impact of extremely low frequency magnetic field-assisted fermentation on Arabica coffee caffeine content

Abstract

Arabica coffee exhibits a superior flavor profile compared to other coffee varieties; however, its relatively high caffeine content necessitates an environmentally friendly decaffeination method. The purpose of this study was to analyze the reduction of caffeine levels, fermentation pH, bean pH, and bean density through a wet fermentation process assisted by an Extremely Low Frequency (ELF) magnetic field. The research was conducted using a 3×2 factorial design. The process was carried out using variations in magnetic field intensity (control, 300 µT, and 500 µT) and contact times (30 and 60 minutes). Fermentation was carried out for 20 hours utilizing tape yeast as a starter, followed by the measurement of fermentation pH every 5 hours, and the subsequent characterization of bean pH, density, and caffeine levels. The application of an ELF magnetic field during fermentation holds the potential to increase microbial activity, thereby reducing the caffeine levels of the coffee beans. The results showed that the fermentation and bean pH values decreased, accompanied by an increase in density; however, these values were not significantly different among the groups (p-value > 0.05). The best treatment was obtained from an intensity of 300 µT with a contact time of 30 minutes, resulting in a caffeine content of 0.0234%. This was lower than the negative control (0.0329%), representing a 28.9 percent reduction. Based on the results of the study, it was concluded that ELF magnetic field exposure at specific intensities and contact times optimizes fermentation, allowing effective caffeine degradation.

Keywords: ELF Magnetic Field, Arabica Coffee, Fermentation, Caffeine.