Behavior of Staphylococcus aureus in Cheddar Cheese Made with Sodium Chloride or a Mixture of Sodium Chloride and Potassium Chloride

Publisher Website
Google Scholar
Abstract
Stirred-curd Cheddar cheese was manufactured from milk artificially contaminated with < 1000 Staphylococcus aureus cells/ml. Lactic starter culture was added to the milk at the rate of 1.0 or 0.5% (v/v). Curds were divided and salted with either NaCl or a mixture of KCl/NaCl to achieve final salt concentrations of approximately 2.4 or 1.2%. Some portions of curd remained unsalted. Cheeses were analyzed for moisture and salt content and were stored at 4 or 10°C for 8 weeks. Bacterial counts and pH values were determined during manufacture and storage of cheeses. Unsalted cheeses had the lowest and the 2.4%-salted cheese had the highest S. aureus counts. Cheeses salted with KCI/NaCl had considerably lower S. aureus and non-S. aureus counts than did cheeses salted with NaCl. All cheeses made with 1.0% starter culture had appreciably lower counts of S. aureus than did cheeses made with 0.5% starter culture. Low levels (0.05 to 0.52 ng/g) of enterotoxin A were found in 16 of 17 samples tested with the radio im...