Today cow’s milk is still one of the most popular (especially in the United States) animal milks consumed by humans. Around the world, people drink the milk from many other animals including camels, goats, llamas, reindeer, sheep and water buffalo.
Most milk packs a nutritional punch and contains protein, calcium, phosphorus, vitamins A and D, Lactose (milk sugar) and riboflavin. On the minus side, milk’s natural sodium content is quite high. Most milk sold in the United States today is Pasteurized, which means the microorganisms that cause diseases (such as salmonella and hepatitis) and spoilage have been destroyed by heating, then quick-cooling, the milk.
Pasteurization eliminates the possibility of disease and gives milk a longer shelf life. In 1993, the Federal Drug Administration approved supplementing dairy cows with a genetically produced hormone protein known as bovine somatotropin (BST). BST is a naturally occurring growth hormone that’s found in all cows. When bioengineered BST is injected into dairy cows, their milk production increases by up to 25 percent.
Scientists assert that the composition of milk from BST-injected cows is not altered in any way and has no biological effect on humans, although many opponents are not convinced. Milk is available in many varieties.
Whole Milk is the milk just as it came from the cow and contains about 3% percent milk fat.
Lowfat milk comes in two basic types: 2 percent, meaning 98 percent of the fat has been removed; and 1 percent, which is 99 percent fat-free. A few lowfat milks contain only 1/2 percent milk fat but they’re not widely available.
Nonfat or skim milk must by law contain less than 1/2 percent milk fat. Federal law requires that both lowfat and nonfat milk be fortified with 2,000 International Units (IU) of vitamin A per quart.
Though vitamin D fortification is optional, 400 IU per quart is usually also added.
Buttermilk of times past was the liquid left after butter was churned. Today it is made commercially by adding special bacteria to nonfat or lowfat milk, giving it a slightly thickened texture and tangy flavor.
Ultrapasteurized milk has been quickly heated to about 300 degrees F, then vacuum-packed. It may be stored without refrigeration for up to 6 months until opened, after which it must be refrigerated. Though the high heat destroys spoilage-causing microorganisms, it also gives a cooked flavor to the milk.
Chocolate is whole milk with sugar and chocolate added to it. Chocolate milk (sometimes labeled simply chocolate drink) is skim milk with the same flavorings added. In either case, if cocoa is used instead of chocolate, the product is labeled chocolate-flavored drink.
There are a variety of dry milk and canned milk products on the market.
Buying milk: Always check the date on the carton to make sure the milk you’re buying is the freshest available. Pull dates are intentionally conservative, and most milk in a market with rapid turnover will keep at least a week after purchase.
Storing milk: Refrigerate milk as soon as you get it home from the store. Milk readily absorbs flavors so always close milk cartons or other containers tightly. The storage life of milk is reduced greatly when allowed to sit out at room temperature for 30 minutes or more, as it would if put in a pitcher for serving.