Milk Products
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Milk in its natural form, directly from a cow, is called raw milk. It is an extremely versatile product from which a myriad of commercial products are derived.
A. Whole Milk, Low-fat Milk, and Skim Milk
Since the fat in raw milk is lighter in weight than the rest of the milk, it will naturally rise to form a layer of cream if allowed to stand. Spinning the milk in a large machine, called a centrifuge, accelerates the formation of a cream layer, or the separation of fat, from raw milk. Varying amounts of fat are removed from the raw milk, resulting in different kinds of fresh milk. If the fat content is lowered to 3.25 percent, the milk is sold as whole milk. Low-fat milk typically has 1 percent or 2 percent fat. Skim milk, or nonfat milk, is the liquid that remains after removing all the cream; it contains about half a percent milk fat. About half of the milk produced in the United States is consumed as one of these types of fresh milk; the rest is processed into other products such as cream, butter, cheese, yogurt, and ice cream.
Once the fat level has been reduced to the desired level, most fresh milk is homogenized to prevent the further separation of a cream layer. Homogenization is accomplished by forcing hot milk under high pressure through small nozzles. The fat globules become so small that they remain evenly dispersed throughout the milk. In order to insure its safety for human use, almost all milk undergoes pasteurization, in which milk is heated to a high temperature for a specified length of time to destroy pathogenic bacteria. Pasteurized milk can be stored in a refrigerator for a week or longer. Ultrapasteurized milk, common in Europe and Canada, is heated to an even higher temperature and can be stored at room temperature for several weeks.
Condensed, evaporated, and powdered milk are produced by evaporating some or all of the water in milk. Sweetened condensed milk is sweetened with the addition of sugar. These products have very long shelf lives.
B. Cream, Butter, and Ice Cream
C. Yogurt, Cheese, and Other Fermented Milk Products
Milk in its natural form, directly from a cow, is called raw milk. It is an extremely versatile product from which a myriad of commercial products are derived.
A. Whole Milk, Low-fat Milk, and Skim Milk
Since the fat in raw milk is lighter in weight than the rest of the milk, it will naturally rise to form a layer of cream if allowed to stand. Spinning the milk in a large machine, called a centrifuge, accelerates the formation of a cream layer, or the separation of fat, from raw milk. Varying amounts of fat are removed from the raw milk, resulting in different kinds of fresh milk. If the fat content is lowered to 3.25 percent, the milk is sold as whole milk. Low-fat milk typically has 1 percent or 2 percent fat. Skim milk, or nonfat milk, is the liquid that remains after removing all the cream; it contains about half a percent milk fat. About half of the milk produced in the United States is consumed as one of these types of fresh milk; the rest is processed into other products such as cream, butter, cheese, yogurt, and ice cream.
Once the fat level has been reduced to the desired level, most fresh milk is homogenized to prevent the further separation of a cream layer. Homogenization is accomplished by forcing hot milk under high pressure through small nozzles. The fat globules become so small that they remain evenly dispersed throughout the milk. In order to insure its safety for human use, almost all milk undergoes pasteurization, in which milk is heated to a high temperature for a specified length of time to destroy pathogenic bacteria. Pasteurized milk can be stored in a refrigerator for a week or longer. Ultrapasteurized milk, common in Europe and Canada, is heated to an even higher temperature and can be stored at room temperature for several weeks.
Condensed, evaporated, and powdered milk are produced by evaporating some or all of the water in milk. Sweetened condensed milk is sweetened with the addition of sugar. These products have very long shelf lives.
B. Cream, Butter, and Ice Cream
C. Yogurt, Cheese, and Other Fermented Milk Products
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