Dairy Chemistry

The most abundant milk protein is casein, of which there are several different kinds, usually designated a-, (1-, and K-casein. The different caseins relate to small differences in their amino acid sequences. Casein micelles in milk have diameters less than 300 nm. Disruption of the casein micelles occurs during the preparation of cheese. Lactic acid increases the acidity of the milk until the micelles crosslink and a curd develops. The liquid portion, known as whey, containing water, lactose and some protein, is removed. Addition of the enzyme rennet (chymosin) speeds up the process by hydrolysing a specific peptide bond in K-casein. This opens up the casein and encourages further cross-linking. 

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Background Briefing Steam Frothing of Milk, Dairy Chemistry, The Institute of Food Science Technology, Dairy Research and Information Center, University of California— Davis, http //drinc.ucdavis.edu/html/dairyc/index.shtml... 

Dairy Chemistry and Physics. Dairy Science and Technology, University of Guelph, http //www.foodsci.uoguelph.ca/dairyedu/chem.html acid... 

There is a colossal amount of information on the Web concerning milk. For example, see the page http //www.sciencebyjones.com/MILK NOTES.HTM or the Dairy Chemistry and Physics page at http //www.foodsci.uoguelph.ca/dairyedu/chem.html, hosted by the Canadian University of Guelph. 

Rollema, H.S. (1992). Casein association and micelle formation. In Fox, P.F. (Ed.). Advanced Dairy Chemistry, Vol. 1 Proteins, London Elsevier Applied Science, pp. 111-140. 

Walstra P., Jenness, R. (1984). Dairy Chemistry and Physics, New York Wiley. 

Ernstrom, C. A. Wong, N. P. Mllk-clottlng enzymes and cheese chemistry. In "Fundamentals of Dairy Chemistry." Eds. Webb,... 

Jenness, R. Patton, S."Principles of Dairy Chemistry", Wiley and Sons, New York, N.Y., 1959. 

The book assumes a knowledge of chemistry and biochemistry but not of dairy chemistry. As the title suggests, the book has a stronger biochemical orientation than either Principles of Dairy Chemistry or Dairy Chemistry and Physics. In addition to a fairly in-depth treatment of the chemistry of the principal constituents of milk, i.e. water, lactose, lipids, proteins (including enzymes), salts and vitamins, various more applied aspects are also covered, e.g. heat-induced changes, cheese, protein-rich products and the applications of enzymes in dairy technology. The principal physical properties are also described. 

Fox, P.F. (ed.) (1982-1989) Developments in Dairy Chemistry, Volumes 1, 2, 3 and 4, Elsevier Applied Science Publishers, London. 

Jenness, R. and Patton, S. (1959) Principles of Dairy Chemistry, John Wiley Sons, New York. 

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