FATE OF SALMONELLA-ENTERITIDIS AND SALMONELLA-TYPHIMURIUM DURING THE FERMENTATION OF ERGO, A TRADITIONAL ETHIOPIAN SOUR MILK

The growth potential of Salmonella enteritidis and Salmonella typhimur ium in milk in smoked and non-smoked containers and their inhibition b y lactic acid bacteria was determined. In the absence of lactic acid b acteria, both Salmonella strains could grow to the level of 10(8) cfu/ ml with 12 h. Smoking of containers significantly retarded Salmonella growth only until 12 h. Growth of lactic acid bacteria in souring milk retarded growth of Salmonella strains and complete inhibition was obs erved between 48 and 60 h at pH and titratable acidity values of 3.7 a nd 0.70%, respectively. The synergistic effect of lower pH, acids and smoking was important in the complete inhibition of the test organisms . Although ergo was preferably consumed after 24 h of fermentation, th e Salmonella strains were not completely inhibited at this time. Thus, traditional making of ergo by the natural fermentation of raw milk co uld he hazardous to health. The use of a three-day old ergo as a start er for boiled milk is recommended to ensure the wholesomeness of ergo.