Treatments with nisin and chelators to reduce salmonella and escherichia coli on beef

Salmonella typhimurium ATCC 14028 or Escherichia coli 0157:H7 attached to lean beef tissue were treated with citrate, lactate, sodium hexametaphosphate, or EDTA, alone or in combination with nisin in simple buffers, and incubated at 4°C for up to 3 days. Lactate with nisin reduced S. typhimurium attached to beef by 040 log₁₀ CFU/cm², while EDTA and nisin reduced E. coli O157:H7 by 0.42 log₁₀ CFU/cm². Unlike earlier in vitro studies in which treatments with nisin and chelating agents resulted in reductions of > 4 log₁₀ CFU/cm2, such reductions were not observed in situ.