Pengaruh Paparan Medan Elektromagnetik Extremely Low Frequency (ELF) terhadap Proses Fermentasi Biji Kopi Arabika (Coffea arabica)

Abstract

The Extremely Low Frequency (ELF) electromagnetic field is an electromagnetic wave within the 0–300 Hz frequency range. This work aimed to evaluate the effect of ELF-EMF exposure on the Arabica coffee beans' fermentation process, particularly evaluating the pH during fermentation, as well as the final pH, density, and caffeine content of the fermented coffee beans. A 3 × 2 factorial design was performed, with the first factor being intensity (control, 300 µT, and 500 µT) and the second factor being exposure time (30 and 60 min). Statistical analysis by ANOVA showed a significant difference compared to the control group at 20 h of fermentation, with the LSD post-hoc test revealing that the treatment exposed to 300 µT for 30 min had the highest pH compared to the control. Meanwhile, the Kruskal-Wallis analysis indicated a significant difference in the coffee beans' pH and density. The Mann-Whitney post-hoc test demonstrated that the 300 µT for 60 min treatment presented a higher pH than the control. Furthermore, the highest density was observed in the treatment exposed to 500 µT for 60 min. The treatment exposed to 300 µT for 30 min showed a decrease in caffeine content after fermentation compared to the control. Thus, these results indicate that ELF-EMF influences the Arabica coffee beans' fermentation process, which is dependent on the appropriate intensity and exposure time.