In Vitro Antibacterial Activity and Gas Chromatography–Mass Spectrometry Analysis of Liquid Smoke of Rice Husk

Abstract

Liquid smoke of rice husk is one of the byproducts of the biochar manufacturing process. One of its applications in the world of food production is its potential as an antibacterial. But there is no scientific data to support this information. This study aims to scientifically determine the content of the main active compounds of rice husk liquid smoke and its potential in antibacterial activity. Five liquid smoke of rice husk samples were collected from different production batches. The antibacterial activity testing was carried out at the Pharmacology laboratory of Faculty of Veterinary Medicine UGM, while the identification of active compounds with the GC-MS test was carried out at the organic chemistry laboratory, Faculty of Mathematics and Natural Sciences UGM to determine the active compound content. Antibacterial activity test was carried out by the planting disk method and diffusion method by making wells on agar media. Based on the results of tests with GC-MS it is known that the main active compounds are Acetic acid at 25.06%, Cyclopropane, 1,1-dibromo-2-chloro-2-fluoro- at 8.58%, Cyclohexanol, 1-ethynyl-, carbamate at 6.64% and 2-Propanone at 6.07%. These compounds in biological activity have the ability to inhibit the growth of gram-positive and negative bacteria. The antibacterial activity test with the diffusion method showed a real bacterial inhibition zone with a mean of 3.62 mm from all test samples. Whereas the disk planting method did not show tangible results for the bacterial inhibition zone. The difference in results between the disk and diffusion methods is probably due to the ability of the liquid smoke to diffuse to make it easier through the wells than to be implanted in the disk. Based on the results of this study indicate that liquid smoke of rice husk has the ability as an antibacterial and has the potential to be developed further as a natural disinfectant.