THE SHELF-LIFE OF DAIRY-PRODUCTS .3. FACTORS INFLUENCING INTERMEDIATEAND LONG-LIFE DAIRY-PRODUCTS

In this, the third part of a series of four reviews, the factors which control the shelf-life of long and intermediate life daily products a re discussed. Two distinct types of product degradation are addressed. Firstly, the degradative potential of heat-resistant lipase, protease and phospholipase, derived from psychrotrophic bacteria commonly foun d in refrigerated milk, is examined. Secondly, the chemical compositio n of milk is reviewed and lipid oxidation, calcium induced aggregation of milk protein and Maillard reaction are identified as likely routes to product spoilage. The relative importance of these reactions to sp ecific products will be discussed in the final part of this series of articles.