REDUCTION OF MICROORGANISMS ON BEEF SURFACES WITH ELECTRICITY AND ACETIC-ACID

This study determined the effect of a 2% acetic acid spray, pulsed-pow er electricity, pulsed-power electricity with a spray of sterile deion ized water, and a combination of acetic acid spray and pulsed-power el ectricity in reducing the pathogens Escherichia call O157 and Salmonel la typhimurium and aerobic plate counts on beefsteaks compared to an i noculated control. Ten steaks per treatment were inoculated with 1 ml of E. coli O157 (10(5) CFU/ml) or S. typhimurium (10(5) CFU/ml) for 2 min and then subjected to one of the five treatments. Acetic acid spra y and acetic acid spray and pulsed-power electricity treatments signif icantly (P <.05) reduced the incidence of Escherichia coli O157 compar ed to inoculated controls and produced a 1-log CFU/cm(2) reduction in the incidence of S. typhimurium. Ten steaks per treatment were also in oculated with 1 ml of S. typhimurium (10(5) CFU/ml) for 2 min, treated with acetic acid spray, pulsed-power electricity and a sterile deioni zed water spray, or acetic acid spray and pulsed-power electricity and stored in an incubator at -2 degrees for 48 h to stimulate chill-cool er conditions in the beef industry. Acetic acid spray with and without pulsed-power electricity caused a 1-log CFU/cm(2) reduction in S. typ himurium. These data indicate a need for the use of both 2% acetic aci d and pulsed-power electricity in packinghouse facilities to help achi eve the goal of improved microbiological safety of beef.