Behavior of Salmonella enteritidis During the Manufacture, Ripening, and Storage of Feta Cheese Made from Unpasteurized Ewe's Milk

Abstract

The ability of Salmonella enteritidis to grow during the Feta cheese-making process and to survive during ripening and storage of the cheese was investigated. Unpasteurized whole ewe's milk was inoculated to contain 106–107 CFU/ml of S. enteritidis and was processed into Feta cheese following standard procedures. All samples were examined for S. enteritidis both quantitatively and qualitatively, while moisture, fat, water activity, and pH values were also measured. S. enteritidis was enumerated in duplicate samples by surface plating on SS agar. Selected Salmonella colonies were identified biochemically and serologically. The enumerations have shown that S. enteritidis was entrapped in curd with the population increasing to a maximum during the First 48 h. Thereafter, the growth of S. enteritidis was inhibited and surviving cells persisted in the curd for up to 20 d.