A study of antimicrobial activity of dried and extrudate from ‎bitter gourd fruit against foodborne pathogens

Abstract

Momordica charantia L., bitter gourd (BG) is a common fruit found in tropical regions.  Due to its benefits to human health its cultivation has started in non-tropical countries as well. This study aims to evaluate and screen the antimicrobial properties of hot air dried, spray dried, and extrudate of bitter gourd fruit on selected Gram-negative, Gram-positive bacteria and one strain of yeast through disk diffusion, minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) assays. Time-kill curve was determined for tested microorganisms. Candida albicans was resistance to all bitter gourd dried fruit extracts in disk diffusion assay. However, K. pneumoniae and S. epidermidis were susceptible to all tested extracts. B. cereus, E. coli, S. mutans, S. aureus and P. aeruginosa recorded different potential level of growth inhibition towards extracts. The study results effectively concluded that bitter gourd ethanol extract of extrudate at 80°C and hot air dried have significant antibacterial effect recorded by having lowest MIC values. The time-kill needed to destroy the bacteria was within 4 h, except for P. aeruginosa. In conclusions, the crude extracts of bitter gourd fruit possessed bactericidal and bacteriostatic activities against foodborne bacteria.