SCREENING OF POTENTIAL MICROBIAL ISOLATES FROM CIVET FECES IN TANGKUBAN PERAHU AS A STARTER CULTURE OF WEST JAVA ARABICA COFFEE (COFFEA ARABICA) WET FERMENTATION

• Main Author: Nauli Triputri Siagian, Monica
• Format: Final Project
• Language: Indonesia
• Subjects: Ilmu hayati ; Biologi
• Online Access: https://digilib.itb.ac.id/gdl/view/85711
• Institution: Institut Teknologi Bandung

Coffee consumption continues to increase, reaching 10 million tons by 2023. The wet post-harvest method is the most commonly used in coffee processing. However, this method is still done traditionally, causing fermentation to occur spontaneously and uncontrolled, resulting in inconsistent coffee flavor quality. One of the famous coffees from Indonesia is kopi luwak, which is known to be influenced by microbes from its digestive system and can be a source of fermentation starter culture. Therefore, this study aimed to screen microbial isolates from civet feces in Tangkuban Perahu as starter cultures for wet fermentation of Arabica coffee in West Java. The selection of starter culture was based on the enzymatic ability of microbes, namely amylolytic, cellulolytic, pectinolytic, and proteolytic. The research began by conducting qualitative enzyme production tests and semi-quantitative enzymatic activity tests on 17 microbial isolates obtained from previous studies. Two yeast isolates with the best enzyme performance were identified as Hanseniaspora uvarum and Nakaseomyces glabratus. H. uvarum was able to produce amylase (4.57 ± 0.31 cm), cellulase (5.90 ± 0.16 cm), and pectinase (4.27 ± 0.09 cm) enzymes. N. glabratus was able to produce amylase (5.61 ± 0.22 cm), cellulase (5.55 ± 0.04 cm), and protease (7.96 ± 0.36 cm). Based on the observation of microbial growth, the best harvesting time for H. uvarum was 7.5 hours and N. glabratus was 6 hours. Controlled fermentation of Arabica coffee was carried out by adding 10% (v/w) starter culture with a cell count of 107 CFU/mL. The fermentation variations were single H. uvarum, single N. glabratus, combination of both yeasts 1:1, and control (without the addition of starter culture). Fermentation was carried out at room temperature for 12 hours by observing microbial growth, measuring temperature, and pH. After 12 hours, the coffee beans were washed and dried until the moisture content reached 11-12%. The results of microbial enumeration showed that the addition of starter culture was able to increase the number of yeast at hour 0th to 6th, as well as the number of bacteria and lactic acid bacteria (LAB) at hour 6th to 12th. The starter culture was also able to dominate during fermentation. The variation of the single addition of N. glabratus had a significant effect on coffee flavor, by consistently getting the best cupping score in the SCA2004 and CVA2024 tests, namely 81.75 and 80.81, and in the hedonic test this variation got the highest cupping score, namely 85. The coffee produced by the single variation of N. glabratus was well received by Q-graders and coffee consumers.