Combinations of food antimicrobials at low levels to inhibit the growth of Salmonella sv. Typhimurium: a synergistic effect?

The use of many antimicrobial compounds in combination can achieve a good microbiological safety in food while decreasing the doses of each compound in the product. This is interesting in terms of consumer demand. In that context, combinations of five aromatic compounds (thymol, carvacrol, citral, eugenol, geraniol) and four acidic compounds (acetic acid, citric acid, lactic acid, pyropolyphosphoric acid) were investigated for their ability to inhibit the growth of Salmonella sv. Typhimurium. Many combinations of either acidic or aromatic compounds appear to be promising. Some antimicrobials, like citric acid or thymol, lead to a better amplification of inhibition than others, but no real synergistic effect has been demonstrated between compounds. Moreover, our results underline that it is important to take into account the cumulative effect of each compound when compounds are mixed.