Impact of gas micro‐nano‐bubbles on the efficacy of commonly used antimicrobials in the food industry

Aim To study the impact of incorporating micro‐nano‐bubbles (MNBs) in commonly used food antimicrobials (AMs) against Escherichia coli O157:H7 (EC) and Listeria monocytogenes (LM). Methods and Results Air, carbon dioxide (CO 2 ) and nitrogen (N 2 ) were used to incorporate MNBs in city water. AM solution (with or without MNBs) of 9 ml was individually taken into sterile test tubes and mixed with 1 ml of inoculum grown in brain heart infusion (BHI) broth to get the net AM concentrations of 28·4 ppm peracetic acid (PAA), 200 ppm chlorine (Cl 2 ), 5·4% citric acid (CA) and 4·5% lactic acid (LA). After treatment time of 1·5 and 3·0 min, 1 ml of sample was neutralized using Dey–Engley neutralizing broth and plated on BHI agar. For EC, Cl 2 ‐CO 2 solutions resulted in significantly greater log reductions (5·2 logs) compared to that of Cl 2 solutions without MNBs (3·8 logs). For LM, PAA‐CO 2 solutions resulted in significantly greater log reductions (4·4 logs) compared to that of PAA solutions without MNBs (1·7 logs). Conclusions This study demonstrated that the efficacy of Cl 2 and PAA AM solutions could be increased by incorporating CO 2 ‐MNBs against EC and LM in microbiological growth medium. Significance and Impact of the Study Incorporation of CO 2 ‐MNBs in AM solutions could increase the efficacy of AMs against pathogens on/in food matrices, which should be tested in future research.