Casein

Casein, group of proteins precipitated when milk is mildly acidified. Casein constitutes about 80% of the total proteins in cow's milk and about 3% of its weight. It is the chief ingredient in cheese. When dried, it is a white, amorphous powder without taste or odor. Casein dissolves slightly in water, extensively in alkalies or strong acids.

Casein is used as a food supplement and as an adhesive, a constituent of water paints, and a finishing material for paper and textiles. A variety of casein, known by the modified name paracasein, is preferred for making a plastic, through the reaction of the casein with formaldehyde, that goes into the manufacture of buttons and other small objects. It is produced by adding the enzyme rennin to milk, forming a precipitate different from the material precipitated by acids.

Calorie

Calorie, metric unit of heat measurement. The small, or gram, calorie (cal) is usually specified in science and engineering as the amount of heat required to raise the temperature of 1 g of water from 14.5° to 15.5° C. The temperature interval is sometimes specified in other ways. The definition now generally accepted and standard in thermochemistry, is that 1 cal equals 4.1840 joules (J).

A slightly different calorie is used in engineering, the international calorie, which equals 1/860 international watt-hour (W h). A large calorie, or kilocalorie (Cal), usually referred to as a calorie and sometimes as a kilogram calorie, equals 1000 cal and is the unit used to express the energy-producing value of food in the calculation of diets.

Antioxidants in Industry

Antioxidants are also used in industry as product additives and in food processing and preservation. Industrial antioxidants slow or prevent oxidative damage that causes food to spoil, rubber to harden, fats and oil to change color or go rancid, and gasoline to oxidize. Foods that are commonly preserved with antioxidant additives include cheese, bread, and oil. Antioxidants used as food preservatives include vitamin C and the synthetic antioxidants butylated hydroxytoluene (BHT) and butylated hydroxyanisole (BHA). These antioxidants are added to foods in concentrations of much less than 1 percent.