Evaluation of Antibacterial Activity of Annatto Dye on Streptococcus Pyogenes, Escherichia Coli, Enterococcus Faecalis, and Bacillus Subtilis

Evidence has identified the harmful effects of antibiotics and synthetic preservatives used in foodstuffs. Therefore, researchers are looking for natural and safe alternatives. Annatto is carotenoid dye and can be used in food industry. This dye has antimicrobial and antioxidant properties. This study aimed to evaluate the antimicrobial effects of annatto dye on the some pathogenic and spoilage bacteria. Annatto dye was extracted by maceration methods and after filtration; it was powdered by a vacuum oven. Antimicrobial activity was evaluated by disc diffusion method and the Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) were determined using agar dilution method. Then, the data were entered into the SPSS statistical software (v. 16) and analyzed using one-way ANOVA and Tukey’s test. The results revealed the effectiveness of annatto dye in the growth of all the tested bacteria. Bacillus subtilis and Escherichia Coli (E.Coli) showed the lowest and highest sensitivity to annatto dye, respectively. Moreover, E.coli had the highest MIC among the bacteria under study, but MBC was not observed in E.coli in any annatto dye concentration. Gram-positive bacteria were more sensitive than gram-negative bacteria to the antimicrobial activity of annatto dye. According to the results, annatto dye can be used as an inhibitor of bacterial growth.