title: Reduction of Listeria monocytogenes and Escherichia coli O157:H7 numbers on vacuum-packaged fresh beef treated with nisin or nisin combined with EDTA.
abstract: Nisin or nisin combined with EDTA was used to treat fresh beef. Beef cubes (2.5 by 2.5 by 2.5 cm) that were inoculated with approximately 7 log CFU/ml of Listeria monocytogenes Scott A or Escherichia coli O157:H7 505 B were dipped in the following solutions: (i) H2O, (ii) HCl, (iii) nisin, (iv) EDTA, or (v) nisin combined with EDTA, respectively, for 10 min each, with an exception of one set of control beef samples without treatment. Beef samples were then drip-dried for 15 min, vacuum packaged, and stored at 4 degrees C for up to 30 days. The pH on beef after different treatments was not a key factor in preventing bacterial growth. Treatment with nisin or with nisin combined with EDTA reduced the population of L. monocytogenes by 2.01 and 0.99 log CFU/cm2 as compared to the control, respectively, under the conditions of vacuum package and storage at 4 degrees C for up to 30 days. However, the effect of nisin and nisin combined with EDTA against E. coli O157:H7 505 B was marginal at 1.02 log CFU/cm2 and 0.8 log CFU/cm2 reductions, respectively.
authors.affiliation: Department of Food Science and Human Nutrition, University of Missouri, Columbia 65211, USA.
authors.forename: S
authors.initials: S
authors.lastname: Zhang
authors.forename: A
authors.initials: A
authors.lastname: Mustapha
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000494:pharmacology*; D002417:Cattle; D004492:Edetic Acid / Q000494:pharmacology*; D019453:Escherichia coli O157 / Q000302:isolation & purification*; D018857:Food Packaging; D005519:Food Preservation / Q000379:methods*; D008089:Listeria monocytogenes / Q000302:isolation & purification*; D008460:Meat / Q000382:microbiology*; D009561:Nisin / Q000008:administration & dosage / Q000494:pharmacology*; D014618:Vacuum
chemical_list: D000900:Anti-Bacterial Agents; D009561:Nisin; D004492:Edetic Acid