Synergistic effect of selected herb and spices extracts against bacterial strains causing food spoilage

Cinnamon, clove and mustard belongs to class of spices while oregano is herb. They are found to have the bioactive compounds. Phytochemical present in cinnamon is 70%-90% cinnamaldehyde, in clove eugenol content is around 95%, in mustard 71% allyl-isothiocyanate is present and oregano contains carvacrol and thymol 30% and 27% respectively along with many others phytochemicals. These plant derivatives possess antimicrobial activity against food borne pathogens and food spoilage bacteria. So, the present study was intended to analyze synergistic effect existed for various combinations of extracts used against selected food spoilage and pathogenic bacteria. For this purpose, the aqueous and ethanolic extracts of cinnamon, clove, mustard and oregano were prepared and concentrated by using shaking incubator and rotary evaporator. Various combinations were made out of these extracts and different concentrations of these extracts were used to analyze the antimicrobial potential against Bacillus subtilis, Pseudomonas aeruginosa, Klebsiella pneumoniae and Escherichia coli by using disc diffusion method. Ethanolic extract of combination of cinnamon, clove and mustard revealed the best zones of inhibition (13.87 ± 0.78 mm), (13.27 ± 0.38 mm), (13.47 ± 0.38 mm), (12.27 ± 0.56 mm) against B. subtilis, P. aeruginosa, K. pneumoniae and E. coli, respectively. The minimum zone of inhibition was observed in case of aqueous extract. The results revealed that cinnamon, clove, mustard and oregano extracts have significant results against these microorganisms. Conclusively, these extracts can be utilized as biopreservatives or to control spoilage in different food products after toxicological studies.