Survival of faecal streptococci in raw and pasteurised egg products

Abstract

1. The ability of Streptococcus faecalis and Streptococcus faecium strains to survive in egg albumen and liquid whole egg before and after laboratory pasteurisation was studied. 2. Pasteurisation of egg albumen caused a decrease in viable cells of less than 10-fold, while pasteurisation of whole egg caused decreases of more than 100-fold in only two of the eight strains studied. After growth in whole egg, some strains were more resistant to pasteurisation in whole egg. 3. Strep. faecalis multiplied in raw and pasteurised whole egg but not in egg albumen. 4. Strep. faecium multiplied in raw and pasteurised whole egg only after an initial decline in viability which was not shown by cells adapted to whole egg. Together with storage temperature this affected the number of viable cells after a storage period of 5 d. 5. In raw and pasteurised egg albumen Strep. faecium strains lost viability; this was maximal at 37 degrees C and more cells survived as the storage temperature decreased.

Storage Stability of Liquid Egg Products Below 0 C

“…Gram negative bacteria were predominant in the unpasteurized whites. Seviour and Board (1972), , and Suzuki et al (1979) reported that Gram negative bacteria such as Aeromonas, Enterobacteriaceae, Flavobacterium, and Pseudomonas were predominant in unpasteurized liquid egg products and in spoiled shell eggs, and Shafi et al (1970), Payne et al (1979), and Payne and Gooch (1980) stated that gram positive bacteria such as Bacillus, coryneform, Micrococcus, and Staphylococcus were predominant in pasteurized liquid egg products. The microbiological findings obtained in this study agreed generally with the results obtained by these researchers.…”