Efficiency of cinnamon and clove essential oils as sanitizers in the food industry

The traditional chemical sanitizers used in the food industry have the disadvantage of a possible development of bacterial resistance and adaptation, interfering with their minimum bactericidal efficiency. Essential oils with antimicrobial activity arouse great interest in the food industry for their possible use as active ingredients of sanitizers. This study aimed to determine the minimum inhibitory concentration (MIC) of cinnamon and clove essential oils (EOs) against Gram-positive (Staphylococcus aureus and Listeriamono cytogenes) and Gram-negative (Escherichia coli and Salmonella sp.) bacteria, as well as compare it with the MIC of sodium hypochlorite, and to determine the minimum bactericidal concentration (MBC) of EOs for L. monocytogenes. The microdilution method was used and the EOs were chemically characterized by gas chromatography - mass spectrometry. The main components of the cinnamon and clove EOs were respectively cinnamaldehyde (67.58%) and eugenol (77.58%). The cinnamon EO MIC was 0.04% for Gram-positive bacteria and < 0.02% for Gram-negative bacteria. The clove EO showed MIC of 0.04% for Salmonella sp., 0.06% for E. coli and S. aureus and 0.08% for L. monocytogenes. For all bacteria tested the sodium hypochlorite MIC was > 0.2%. The MBC for L. monocytogenes of the clove EO was 0.18%, while the cinnamon EO distinguished itself for presenting MBC < 0.02%, demonstrating the possibility of using these EOs, especially the cinnamon one, as active principles of sanitizers.