Effect of Non-Salting of Cheddar Cheese Made with Induced Starter Failure on Growth of Clostridia and Keeping Quality of Processed Cheese

Abstract

Batches of pasteurized milk inoculated with spores of Clostridium sporogenes, C. perfringens, C. butyricum and C. tyrobutyricum were used to produce 8 batches of Cheddar cheese without starter activity. At the end of cheddaring, half the curd was salted and each curd portion was pressed separately for 18 h at ambient temperature. The cheese was stored for 6 weeks at both 11 and 4 C then processed. Samples of each batch of processed cheese were maintained at room temperature and at 37 C for at least 10 months. The results showed that although the salted cheese (SC) contained 5% salt-in-moisture and less moisture content than that of the unsalted cheese (USC), no appreciable difference was observed in growth rate of clostridia in both USC and SC. After processing, there was no significant difference between spore counts in the cheese originating from either USC or SC. No defects which could be attributed to clostridial activity developed during storage. Browning of processed cheese stored at 37 C was far greater in batches originating from SC as compared with those originating from USC. Results of this investigation were compatible with results published previously regarding omission of salting of low acid Cheddar cheese with the object of retarding Staphylococcus aureus growth and enterotoxin production.