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) againstEscherichia coliO157:H7 (EC) andListeria monocytogenes(LM). Methods and Results Air, carbon dioxide (CO2) 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 center dot 4 ppm peracetic acid (PAA), 200 ppm chlorine (Cl-2), 5 center dot 4% citric acid (CA) and 4 center dot 5% lactic acid (LA). After treatment time of 1 center dot 5 and 3 center dot 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 center dot 2 logs) compared to that of Cl(2)solutions without MNBs (3 center dot 8 logs). For LM, PAA-CO(2)solutions resulted in significantly greater log reductions (4 center dot 4 logs) compared to that of PAA solutions without MNBs (1 center dot 7 logs). Conclusions This study demonstrated that the efficacy of Cl(2)and PAA AM solutions could be increased by incorporating CO2-MNBs against EC and LM in microbiological growth medium. Significance and Impact of the Study Incorporation of CO2-MNBs in AM solutions could increase the efficacy of AMs against pathogens on/in food matrices, which should be tested in future research.