Antibacterial Potential of Radish Extract (Raphanus sativus L.) Against Fish Spoilage Bacteria

Abstract

Radish ( Raphanus sativus L.) root is commonly used  as flavor enhancing additive or side dish. Previous research revealed the presence of active compound in which could inhibit bacterial growth. Thus, a research concerning natural antibacterial for fish products that are categorized as high-risk food being contaminated by spoilage bacteria ( Pseudomonas aeruginosa, Bacillus cereus, dan Staphylococcus aureus ) was done. Radish root extraction was made by using ethyl acetate (semi polar) for 3 days. Well diffusion was performed using 4 extract concentration (10, 20, 30, dan 40% (w/v)) againts  three fish spoilage bacteria. Based on our results, 30% concentration was the best concentration which inhibit more than 10 mm in inhibition zone with MIC  and MBC. The scores were of 0.06% and 0.24% ( P. aeruginosa ), 0.13% and 0.50% ( S. aureus ), and 0.12% and 0.48% ( B. cereus ). Moreover, based on stability test against heating temperature showed that this extract concentration was more stable in 80°C with duration times for 5 minutes and pH 3 which resulting the lowest inhibition zone reduction compares to control extract. Radish extract was categorized as low toxic compound (LC 50 = 839.52 ppm) functioning in antibacterial compound containing major antibacterial compound ( bis(2-ethylhexyl) phthalate , 1,2- benzenedicarboxylic acid , 9,12,15-octadecatrienoic acid ), fatty acid ( n-hexadecanoic acid , butanedioic acid ), carboxylic acid ( isobutyric acid , malic acid , oleic acid ), and minor antibacterial compound ( n-Hydroxymethylacetamide , 2,4-bis(1,1-dimethylethyl) , 2,4-pentanedione , 2-Cyclohexen-1-one , hydrazine , cyclohexene oxide , gamma-sitosterol ).