Inhibition of bacterial growth on ham and bologna by lysozyme, nisin and EDTA

Ham and bologna sausages were prepared with or without addition of 500 mg kg(-1) lysozyme:nisin, 1:3, and 500 mg. kg(-1) EDTA Sausages were inoculated with one of; Brochothrix thermosphacta, Escherichia coli O157:H7, Lactobacillus sakei, Lactobacillus curvatus, Leuconostoc mesenteroides, Listeria monocytogenes, Salmonella typhimurium, Serratia grimesii or Shewanella putrefaciens, vacuum packed and stored for 4 weeks at 8 degrees C. Plate counts were made on selective and nonselective media. Inhibitor treatment reduced initial populations of B. thermosphacta and Lc. mesenteroides on both meats. Treatment of ham and bologna prevented growth of B. thermosphacta, to week 4. Treatment reduced growth of Lb. curvatus on ham and bologna, to week 3. Treatment of bologna reduced growth of Lc. mesenteroides and L. monocytogenes for 2 weeks. Treatment of ham reduced growth of E. coli O157:H7 for 4 weeks. On treated ham the growth of S. typhimurium was increased from week 3. No difference was observed between control and treatment samples with other organisms. (C) 2000 Elsevier Science Ltd. All rights reserved.