In-vitro antibacterial activity of plant based phenolic compounds for food safety and preservation

•Antibacterial activity of five important plant derived antimicrobials were evaluated.•Resveratrol at 240 μg/ml resulted in 5.95 log10 CFU/ml reduction of E. coli W1485.•Cinnamaldehyde at 240 μg/ml resulted in 6.2 log10 CFU/ml reduction of B. cereus within 4 h.•Resveratrol and cinnamaldehyde are promising natural antimicrobials for food safety.

Certain plant based natural phenolic compounds exhibit antimicrobial and antioxidant properties. These properties are known to provide health benefits by improving human health. However, their application in the area of food safety is relatively recent. Our objective was to evaluate antibacterial activity of plant derived curcumin, resveratrol, cinnamaldehyde, p-coumaric acid and coniferyl alcohol against E. coli W1485 and B. cereus, as models of common pathogenic microorganisms. Each phenolic compound was studied at four concentrations of 60 μg/ml, 120 μg/ml, 180 μg/ml and 240 μg/ml. E. coli W1485 and B. cereus were inoculated into the phosphate buffer saline (PBS) containing different levels of phenolics. Reductions in cell numbers of test cultures were enumerated by plating aliquots of diluted cultures on tryptic soy agar media and results were expressed in log10 CFU/ml. Up to 5.95 log10 CFU/ml of E. coli W1485 were reduced by resveratrol at 240 μg/ml of concentration and 6.2 log10 CFU/ml of B. cereus were reduced by cinnamaldehyde at 240 μg/ml of concentration within 4 h of incubation. Resveratrol and cinnamaldehyde are promising natural antimicrobials for food safety and preservation.