Week: 14 REFRIGERATED STORAGE. INTRODUCTION PRINCIPLES OF REFRIGERATED STORAGE CONTROL OF MICROBIAL GROWTH DURING REFRIGERATEED STORAGE ESTABLISHING SHELF-LIFE IN REFRIGERATED FOODS DETERIORATION OF PRODUCT QUALITY. INTRODUCTION.
PRINCIPLES OF REFRIGERATED STORAGE
CONTROL OF MICROBIAL GROWTH DURING REFRIGERATEED STORAGE
ESTABLISHING SHELF-LIFE IN REFRIGERATED FOODS
DETERIORATION OF PRODUCT QUALITY
Primary purpose of refrigerating foods is to extend shelf life by slowing down degradation reactions and limiting microbial growth. Through reduction in rates of chemical, biochemical, and microbial kinetics, low--temperature storage can extend the shelf life of fresh and processed foods
By holding food in the temp. range of -l to 8℃.
Factors influencing shelf life of refrigerated foods
Proteases present in foods can alter flavor and texture of many products, including meat and fish, dairy products, and cheese. These enzymes attack protein matter in the food, breaking them down into peptides or shorter chain amino acid sequences. Many of these peptides contribute greatly to flavor changes during storage, while stiffness or texture may also be affected. In meats, for example, proteolysis is in part responsible for softening of tissue after slaughter. This process may take place over a 2 to 5week period in refrigerated storage. In cheese, proteolysis is thought to contribute to generation of characteristic flavors through release of peptides from casein.
Lipases, whether already present or added as part of a product formulation, catalyse hydrolysis of triacylglycerols into fatty acids and other glyceride breakdown products (mono- and diglycerides). Since many fatty acids have characteristic flavors and odors, some of them unpleasant lipolysis causes loss of product quality. An exception to this occurs in certain types of cheeses, where these lipid breakdown products enhance the flavor of the final product after ripening.