THE SHELF-LIFE OF DAIRY-PRODUCTS .2. RAW-MILK AND FRESH PRODUCTS

In the second of this series of articles, the specific factors control ling the shelf-life of raw milk, pasteurized milk and cream, cottage c heese and yogurt are considered. The shelf-life of raw milk depends on the quality of the milk ex-farm and on subsequent transport and stora ge conditions. Shelf-life may be enhanced by deep cooling or thermizat ion. Post heat treatment contamination by Gram negative psychrotrophic bacteria is the major determinant of shelf-life of pasteurized produc ts. In cultured dairy products, yeast and mould contamination is the m ost usual cause of spoilage.