Study of the combined effect of Trachyspermum ammi and Lavandula officinalis essential oils on some foodborne pathogenic bacteria

In this study, the effects of different concentrations of trachyspermum ammi and lavandula officinalis essential oils (eos) were investigated individually and in combination against certain foodborne pathogens, including e. coli, salmonella typhimurium, l. monocytogenes, bacillus cereus, and staphylococcus aureus. the mic of t. ammi essential oil alone against the studied bacteria was as follows: e. coli (1000 ppm), s. typhimurium (2000 ppm), l. monocytogenes (1000 ppm), b. cereus (2000 ppm), and s. aureus (2000 ppm). on the other hand, the mic of l. officinalis alone against the studied bacteria was higher: e. coli (>4000 ppm), s. typhimurium (>4000 ppm), l. monocytogenes (1000 ppm), b. cereus (1000 ppm), and s. aureus (2000 ppm). interestingly, the combined effect of t. ammi and l. officinalis eos demonstrated that a combination of 500 ppm t. ammi eo and 1000 ppm l. officinalis eo could effectively inhibit the growth of e. coli. similarly, a combination of 500 ppm t. ammi eo with 500 ppm l. officinalis eo and 125 ppm t. ammi eo with 1000 ppm l. officinalis eo effectively inhibited the growth of s. aureus. furthermore, the combined mic values for specific bacteria were 1000 ppm t. ammi eo with 3000 ppm l. officinalis eo for salmonella typhimurium, 500 ppm t. ammi eo with 500 ppm l. officinalis eo for l. monocytogenes, and 1000 ppm t. ammi eo with 500 ppm l. officinalis eo for bacillus cereus. overall, the combination of these two essential oils led to an increase in the lag phase and a decrease in the growth rate of the target bacteria, which is significant in food microbiology. in conclusion, the study highlights the importance of the combination application of t. ammi and l. officinalis eos as natural antimicrobial agents in food safety.