Antibacterial Activity of Star Fruit Extract against Vibrio cholera Isolated from Tuna Fish

Aims: This study aims to determine the effect of ethanol concentration and extraction temperature on the characteristics of star fruit extract, that content of bio active, compounds (polyphenol, flavonoid, alkaloids, saponin, and tannin of star fruit) can inhibit bacterial activity as a preservative for tuna.

Study Design: This research was carried out in 2 stages, namely: (1) determine the ethanol concentration and temperature to produce the best extract and (2) determine the antibacterial power of the extract against Vibrio cholera - BSFIL Randomized block design (RBD) with two factors, namely 1 (ethanol concentration 96% and 70%) and 2 (temperature extraction 30ºC, 40ºC and 50ºC. and analysis of variance with Tukey’s honestly significant difference was used to analyze the data.

Place and Duration of Study: This research was conducted at Food Technology laboratory, Faculty of Agriculture Technology, Udayana University on November – April 2022.

Results: The best quality (P=0.05) of star fruit extract by 96% ethanol at 30ºC, such as: yield (77%), total flavonoid (7.10%), total tannin (0.914 mg QE /g), total acids (34.24%). and with a concentration of 80% the extract was able to inhibit the growth of Vibrio cholera (VC-BSFIL) with very strong criteria (inhibition zone diameter: 20.78 mm).