Rennet

Abstract: Volume 1: Cheese: An Overview. General and Molecular Aspects of Rennets. The Enzymatic Coagulation of Milk. Secondary (Non-Enzymatic) Phase of Rennet Coagulation and Post. Coagulation Phenomena. The Syneresis of Curd Cheese Starter Cultures. Salt in Cheese: Physical, Chemical and Biological Aspects. Cheese Rheology. Cheese: Methods of Chemical Analysis. Biochemistry of Cheese Ripening. Water Activity in Cheese in Relation to Composition, Stability and Safety. Growth and Survival of Undesirable Bacteria in Cheese. Application of Membrane Separation. Technology for Cheese Production. Acceleration of Cheese Ripening. Nutritional Aspects of Cheese. Index. Volume 2: Cheddar Cheese And Related Dry Salted Cheese Varieties. Dutch-Type Varieties. Swiss-Type Varieties. Mold-Ripened Cheeses. Bacterial Surface Ripened Cheeses. Iberian Cheeses. Italian Cheeses. Ripened Cheese Varieties Native to the Balkan Countries. Cheese of the Former USSR. Domiati and Feta Type Cheeses. Mozzarella and Pizza Cheese. Fresh Acid Curd Cheese Varieties. Some Non-European Cheese Varieties. Processed Cheese Products from Ewe's and Goat's Milk. Index.

Abstract: Rennet-coagulated cheeses are ripened for periods ranging from about two weeks to two or more years depending on variety. During ripening, microbiological and biochemical changes occur that result in the development of the flavour and texture characteristic of the variety. Biochemical changes in cheese during ripening may be grouped into primary (lipolysis, proteolysis and metabolism of residual lactose and of lactate and citrate) or secondary (metabolism of fatty acids and of amino acids) events. Residual lactose is metabolized rapidly to lactate during the early stages of ripening. Lactate is an important precursor for a series of reactions including racemization, oxidation or microbial metabolism. Citrate metabolism is of great importance in certain varieties. Lipolysis in cheese is catalysed by lipases from various source, particularly the milk and cheese microflora, and, in varieties where this coagulant is used, by enzymes from rennet paste. Proteolysis is the most complex biochemical event that occurs during ripening and is catalysed by enzymes from residual coagulant, the milk (particularly plasmin) and proteinases and peptidases from lactic acid bacteria and, in certain varieties, other microorganisms that are encouraged to grow in or on the cheese. Secondary reactions lead to the production of volatile flavour compounds and pathways for the production of flavour compounds from fatty acids and amino acids are also reviewed.