Submitted to: American Chemical Society National Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 12/1/2012
Publication Date: 4/7/2013
Citation: Tunick, M.H. 2013. Using milk and cheese to demonstrate food chemistry. American Chemical Society 245th National Meeting Abstract. CHED:0025.
Technical Abstract: Students usually do not realize how much chemistry is involved in making a food like cheese, and teachers may use milk and cheese to reveal interesting principles. Cheese is made by lowering the pH of milk, coagulating the protein with enzymes, and removing the whey with heat and pressure. Studies by the USDA's Agricultural Research Service have shown that variations in the procedures lead to different chemical reactions in the curd during processing and storage, resulting in an array of flavors and textures. Some of the chemistry involved may be demonstrated with simple experiments, such as acidifying milk to precipitate casein (demonstrating the isoelectric point) and heating different varieties to compare how far they stretch and the amount of oil coming off (illustrating the importance of the physical state of the protein matrix). Related experiments include adding drops of milk to a glass of water to illustrate light scattering. Experimentation with common foods such as milk and cheese ought to elevate a classroom's interest in chemistry.