Antibacterial effects of natural tenderizing enzymes on different strains of Escherichia coli O157:H7 and Listeria monocytogenes on beef

This study determined the efficacy of actinidin and papain on reducing Listeria monocytogenes and three mixed strains of Escherichia coli O157:H7 populations on beef. The average reduction of E. coli O157:H7 was greater than that of L. monocytogenes and higher concentrations of either protease yielded greater reduction in bacterial populations. For instance, actinidin at 700mg/ml significantly (p≤0.05) reduced the population of L. monocytogenes by 1.49logcfu/ml meat rinse after 3h at 25 & 35°C, and by 1.45logcfu/ml rinse after 24h at 5°C, while the same actinidin concentration significantly reduced the populations of three mixed strains of E. coli O157:H7 by 1.81logcfu/ml rinse after 3h at 25 & 35°C, and 1.94log cfu/ml rinse after 24h at 5°C. These findings suggest that, in addition to improving the sensory attributes of beef, proteolytic enzymes can enhance meat safety when stored at suitable temperatures.