THE FATE OF SALMONELLA-ENTERITIDIS PT4 IN DELIBERATELY INFECTED COMMERCIAL MAYONNAISE

A total of 30 samples (24 different varieties) of commercial mayonnais e deliberately inoculated with Salmonella enteritidis PT4 have been st udied. The fastest death rate of the test organism was obtained with a fat-free mayonnaise pH 2.6. There was a trend indicating that the ant imicrobial attributes of mayonnaise were enhanced when the pH became m ore acid, especially with acetic acid as the acidulant. The looseness of the correlation of death rates with pH in the range 4-5 may well re flect the contribution. of the diverse range of ingredients other than acids to the antimicrobial properties of this commodity. One general statement is possible, in, the majority of mayonnaises S. enteritidis was protected to a limited extent by storage at 4 degrees C viz a viz storage at 20 degrees C.