Balsamic vinegar from Modena: an easy and effective approach to reduce Listeria monocytogenes from lettuce

The microbiological safety of fresh produce is a significant concern of consumers and industry. After applying at an inoculated level (6-7logCFU/mL) of Listeria monocytogenes on Iceberg lettuce, the antilisterial properties of balsamic vinegar from Modena, white wine vinegar and acetic acid solutions were investigated.Different proportions of the vinegars, acetic acid (58.7g/L), and deionized water were evaluated to determine the role of those solutions at the stage of washing Iceberg lettuce to remove L.monocytogenes. The maximum observed log reduction of L.monocytogenes was 2.15±0.04 for balsamic vinegar (50% (v/v)), 1.18±0.06 for white wine vinegar ((50% (v/v)) and 1.13±0.06 for acetic acid ((50% (v/v)). Washing with water only reduces 0.05±0.04logCFU/mL of L.monocytogenes numbers.Listeria reductions observed for balsamic vinegar are similar or higher than those of chlorine-based sanitizers evaluated in other studies with lettuce. In the case of balsamic vinegar solutions, Listeria inhibition followed a linear reduction according to the model: Log (N/N0)=-4.09×balsamic vinegar proportion % (v/v)-0.13; R2=0.95. Balsamic vinegar washings may be a promising method for reducing other foodborne pathogens present in produce or other foods, at home and retail environments.