THE EFFECT OF BACTERIAL AND YEAST CONSORTIUM VARIATIONS IN FERMENTATION OF ROBUSTA COFFEE (COFFEA CANEPHORA) ON COMMUNITY ECOLOGY AND COFFEE TASTE

• Main Author: Caroline, Theresia
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/53721
• Institution: Institut Teknologi Bandung

Coffee is a commercial product in 50 countries with an average daily consumption of more than 3 billion per cup. The largest types of coffee produced by Indonesian plantations are Robusta (± 83%) and Arabica (± 17%). The price of Arabica coffee continues to increase every year by around 4,7% while Robusta continues to decrease by around 0,1% because the taste is preferred by consumers. One way to improve the taste of Robusta coffee is controlled fermentation. This study aims to determine the effect of controlled fermentation on the dynamics of the microbial community during the Robusta coffee fermentation process and the possible effects on the taste of coffee. This research was conducted in several stages. First, microbial screening was carried out for the Robusta coffee fermentation process based on the antagonostic test between bacterial and yeast isolates by using the compatibility test method. Next, a growth curve was made and the identification of selected isolates was carried out by 16s partial sequencing for bacteria and ITS region 1 and 4 rRNA for yeast. The next research stage is to determine the ecological profile of microbes involved in the coffee fermentation process using cluster analysis, species richness, Shannon-Wienner diversity index, Simpson dominance index, and evenness index. From the results of previous research, 20 microbial isolates were found in natural fermentation of Robusta coffee. Screening was carried out to determine the dominant isolate with the enzymatic capacity required for coffee fermentation and from the results of the study it was found that none of the selected isolates had mutually inhibited growth. The indigenously selected microbial species from natural fermentation of coffee are Butiauxella gaviniae (B3), Klebsiella Sp. , Pantoea dispersa (B12), Cyberlindnera fabianii (Y2), Wickerhamomyces anomalus (Y3), and Candida quercitrusa (Y10). In the second screening, 4 isolates were selected to be used in controlled fermentation of coffee. Based on the growth curve, the inoculum age of the selected isolates were determined, namely 4 hours (B3 and B12), 10 hours (Y2), and 7 hours (Y3). The effect of adding inoculum in controlled fermentation can reduce the number of species richness. The coffee sample with the highest total cupping score in the community was dominated by Butiauxella gaviniae, which has the physiological ability to use various sugars l-arabinose, cellobiose, maltose, d-mannose, l-rhamnosa, d-xylose, and salicin to produce acid products whose complexity is suspected influence on the taste of coffee. Based on statistical analysis, the diversity index, dominance, and evenness of each sample with a cupping value ? 80 were not significantly different (p> 0.05).