Bacteriological contamination of egg products after thermal preservation processes

Research was carried out to define the hygienic propriety of thermally trea ted eggs, i.e. eggs treated at pasteurization temperatures and those stored frozen. The average values of the number of the bacteria in the pasteurize d yolk and egg white were log 4.9 and 5.1, respectively, those in the froze n-pasteurized yolk and egg white were log 5.5 and 4.8 and in the frozen yol k and white were log 7.0 and 5.9. The contaminants Salmonella spp., Proteus spp., Staphylococcus aureus, Escherichia coli, Clostridium spp., Clostridi um perfringens, Pseudomonas spp.. Campylobacter jejuni and Yersinia enteroc olitica were tested for 306 samples of pasteurized, frozen and pasteurized and frozen products of eggs, egg-yolks and egg-whites. Presence of Salmonel la spp. in the pasteurized yolk was 12%, Clostridium spp. 16%, E. coli 16% and Proteus spp. 14%, but in the pasteurized egg white those bacteria were present in 10.8%, 15.3%, 13.8% and 10.0%. Staphylococcus aureus was isolate d in yolk at 4.6 and in white 4.0% and Clostridium perfringens 4.0 and 1.5% , respectively. The bacteriological flora indicated that the degree of cont amination of egg-products depends directly on the degree of initial contami nation and correlates with the technological egg-treatment processes applie d.