Fermentasi Biji Kopi Robusta (Coffe canephora) Menggunakan Yeast Komersial (Saccharomyces cerevisiae) sebagai Starter dengan Variasi Media dan Lama Fermentasi

Abstract

Robusta coffee at the farm level is generally only processed into dry coffee beans without involving specific processes. As a result, the coffee produced is of low quality with simple flavours. Nowadays, interest and demand for coffee with complex flavours is increasing, especially by specialty coffee lovers. An alternative solution to improve coffee quality is fermentation. The addition of Saccharomyces cerevisiae starter and control of fermentation variables such as media and duration are intended to improve and optimize the fermentation process. This study used an experimental method with a complete randomized design involving two media variations (water media and mixed media) and three fermentation durations (24, 48 and 72 hours). Coffee analysis included pH, volatile compounds using GCMS, total phenolics and antioxidant activity. The results showed that volatile compounds increased in all fermented coffee compared to unfermented coffee. The number of volatile compounds identified was 103 to 135, higher than unfermented coffee which only identified 85 compounds. The fermentation process also caused changes in coffee characteristics, namely: pH decreased as fermentation time increased; total phenols decreased from 137.98 mg GAE/g to 101.64 mg GAE/g. However, the antioxidant activity increased from 24.25% to 28.88%. In conclusion, this study contributes to understanding the effect of media and fermentation duration on the quality of robusta coffee, so that it can be used as a tool to improve the quality of robusta coffee.