What Does That Mean?
Pasteurization. "Raw" milk is pasteurized to destroy potentially harmful bacteria it may contain and to disable certain natural enzymes. It also increases the "shelf life" of milk. Pasteurization involves the heating of "raw" milk to 145 degrees F (63 degrees C) for 30 minutes; or heating it to 161 degrees F (72 degrees C) for 15 seconds. The pasteurized milk is then rapidly cooled to 38 degrees F. Pasteurization has negligible effect on the taste and nutritive characteristics of milk.
Ultrapasteurization. Ultrapasteurized milk is heated to at least 212 degrees F (100 degrees C) for at least two seconds. The higher temperature treatment destroys all natural bacteria that may be present, rendering the milk microbially stable. Ultrapasteurized milk must still be refrigerated, but its "shelf life" is extended to something like two months. Ultrapasteurization is valued for milk destined for certain commercial applications (i.e., fast food restaurants) and for eggnog and other specialty products where spoilage is an issue. Ultrapasteurization has negligible effect on the taste and nutritive characteristics of milk.
Ultra High Temperature (UHT) pasteurization. In UHT pasteurization, milk is heated to 280 degrees F (138 degrees C) for one-to-two seconds. The use of a very high temperature completely sterilizes all microbes that may be present in the milk, while the short exposure to high temperature minimizes impact on the milk"s taste and nutritive characteristics. UHT milk remains fresh without refrigeration for up to three months provided it remains sealed within its aseptic package. After opening, the package must be refrigerated; the milk will remain fresh about as long as conventionally pasteurized milk.
Homogenization. Homogenization achieves a more permanent and consistent suspension of milkfat in milk. By breaking up and dispersing milkfat globules, milk enjoys a smoother, more uniform texture. Without homogenization, cream would separate from other components of milk and rise to the top. Homogenization involves reducing the diameter of milkfat globules to no more than 0.001 mm by forcing milk through a small orifice under suitable conditions of temperature and pressure (50 degrees C and 200 ATM in the first stage, then 50 ATM in the second stage). Homogenization results in a softer curd in the stomach that eases digestion. Homogenization has no effect on the nutritive characteristics of milk. Homogenized milk must be pasteurized to inactivate the enzyme lipase which can cause milk to taste rancid.
Fortified milk. Few foods, including milk, naturally contain significant amounts of Vitamin D - needed for proper calcification and metabolism of bones and teeth. Approximately 98% of the fluid milk marketed in the U.S. is fortified with Vitamin D to a level of 400 IU per quart. Milk is an excellent vehicle for fortification with Vitamin D because it contains the proportion of calcium and phosphorus required for proper binding to bones and teeth. Vitamin D fortification of milk has been credited with the virtual elimination of rickets in the U.S. Vitamin A - essential for the skin, immune system and vision - is naturally present in whole milk in high but variable quantities. Fortification standardizes Vitamin A levels to 126 IU per 100 g of milk. Since Vitamin A is removed in de-fating, it must be added back to reduced fat, low fat and fat-free milks. Some milks may be fortified with added protein and/or calcium. Protein fortification involves the addition of nonfat milk solids (proteins, carbohydrates) to create a more nutrient-rich product; when added to fat-free milk, proteins enhance the taste and "mouth feel" of the milk. Fortification of milk must be disclosed on the product label.
Goat's milk. Although only a relative handful of Americans drink fluid goat's milk, it is more widely consumed around the world than cow's milk. Goat's milk contains many of the same nutrients as cow's milk. Compared with cow's milk, one cup of goat's milk contains more calories (168 vs. 150), more calcium (326 g vs. 291g), more phosphorus (270g vs. 228g), more protein (8.69 g vs. 8.03g) and more potassium (499 g vs. 370g). Perhaps the greatest benefit of goat's milk is that it can be tolerated by some people who have difficulty digesting cow's milk. However, goat's milk contains only slightly less lactose than cow's milk (4.1% milk solids vs. 4.7%), and so can produce adverse digestive reactions in some people. Goat's milk is lacking in several nutrients critical for growing infants; when feeding infants a goat's milk-based formula, dietary supplementation is necessary.
Sheep's milk. Very little fluid sheep's is consumed in the U.S. Most sheep's milk produced in North America is used to manufacture cheese and yogurt. Compared with cow's milk, sheep's milk is richer in Vitamins A, B and E, calcium, phosphorus, potassium and magnesium. It is denser in protein than cow's milk, but also contains considerably more calories and more fat. Sheep's milk is better tolerated by some people with adverse digestive reactions to cow's milk, even though the two milks contain about the same amount of lactose.
Plant-based beverages. Manufacturers of soy- and rice-based beverages call their products "milk", although legally that title can only be applied to a lacteal secretion. Soy beverage - an emulsion of oil, water and protein - is an aqueous extract of whole soybeans. It contains about the same amount of protein as cow's milk, 2% fat and 2.9% carbohydrate. It is deficient in calcium and some vitamins and is not suitable for infants. A qualified "Heart Healthy" claim approved for use with soy beverage by FDA is disputed by the American Heart Association and the American Medical Association. Rice beverage is derived from brown rice and is sweetened with sugarcane syrup. Compared with cow's milk, it contains about three times as much carbohydrate (due to sweetening). It contains less than 7% of the calcium found in cow's milk and very little protein. It contains little lactose and no cholesterol. Plant-based beverages are frequently fortified with additives to compensate for deficiencies in their nutrient profiles.
Hormones. All foods derived from animals contain trace amounts of protein hormones, usually a few parts-per-billion (ppb). All milk naturally contains a few ppb of bovine somatotropin (bST), a cow growth hormone. However, animal growth hormones are non-reactive in human beings and they produce no effect. A man-made duplicate of bST - called recombinant bovine somatotropin or rbST - is sometimes administered to cows to stimulate them to produce more milk. However, cows do not pass bST into their milk in proportion to the amount in their bloodstream, so milk from rbST-supplemented cows contains the same amount of growth hormone found in milk from unsupplemented cows. Milk from organically raised cows contains the same hormone, in the same amount, as milk from conventionally raised cows. The presence of these hormones in milk should be of no concern to consumers because they are simply proteins that are digested harmlessly in the human stomach.
Antibiotics, pesticides. No milk sold in the U.S. contains dangerous antibiotics or pesticides. Milk is repeatedly tested at the farm and the processing plant to ensure that it conforms to rigorous purity standards mandated by government authorities and the dairy industry. All milk that fails to meet these standards is destroyed before it can enter the human or animal food chains. Detection rates are approximately 100%. The most recent report of the FDA's National Milk Drug Residue testing program found that only 0.019% of all milk reaching processing plants in the U.S. failed to meet required antibiotic standards. All of this milk was destroyed before it could enter the human or animal food chains. The notion that milk is laced with dangerous antibiotics and pesticides is a myth.
ORGANIC milk. "Organic milk" refers to the process by which it was produced, not to the product itself. Organically-produced and conventionally-produced milks are identical in their composition, nutritive characteristics, taste, purity and safety attributes. Organic production methods aim at recycling resources and promoting biodiversity, and these aims are valued by some consumers. However, all milk - regardless of how it was produced - must meet the same strict standards for content, wholesomeness and product safety. Marketing claims that organic milk is different from, and better than, conventionally produced milk have not been scientifically substantiated. www.ams.usda.gov/nop/Consumers/brochure
Milk Varieties - Defenitions of many milk varieties