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 700 mg/ml significantly (p <= 0.05) reduced the population of L monocytogenes by 1.49 log cfu/ml meat rinse after 3 h at 25 & 35 degrees C, and by 1.45 log cfu/ml rinse after 24 h at 5 degrees C, while the same actinidin concentration significantly reduced the populations of three mixed strains of E. coli O157:H7 by 1.81 log cfu/ml rinse after 3 h at 25 & 35 degrees C, and 1.94 log cfu/ml rinse after 24 h at 5 degrees 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. (C) 2013 Elsevier Ltd. All rights reserved.