Milk represents a major ingredient in our diet- poured over cereals, drunk in glasses, in tea and coffee- but it also enters the composition of many dishes especially desserts such as ice-cream, custard, pancakes, rice puddings, etc. It is particularly high in calcium, but it is also fairly in fat.
There are many types of milk consumed though mostly it is cow’s milk, goat’s milk and sheep’s milk.
PASTEURIZATION OF MILK:
Raw milk may contain bacteria that can cause serious illnesses, such as tuberculosis. Pasteurization destroys 100% of pathogenic bacteria, yeast and mould and 95% to 99% of other bacteria. Almost all fresh milk is marketed as pasteurized these days, as this is a precaution to guard against food poisoning. To pasteurize milk one has to heat it to a high temperature below boiling point by one of the two methods:
1) The flash Method: Milk is brought to 71*c. And held there for not less than 15 seconds.
2) Holding Method: In this method the milk is heated to 62*c. and held at this temperature for not less than 30 minutes.
Kinds of Milk:
- Whole milk is often called for in dessert recipes and adds just a touch of extra richness in coffee, soups and other savoury dishes. It can be used in any recipe calling for milk. It is available in cartons, bags, bottles or jugs.
- Partly skimmed milks are the most popular types of milk for everyday use. You can use both 1% and 2% interchangeably in recipes calling for milk. Both are available in cartons, bags, bottles or jugs.
- Skim milk can be used in recipes calling for milk, though it may not provide enough creaminess in recipes using more than 2 cups (500 mL), or in those that specifically call for 1%, 2% or whole milk. It is available in cartons, bags and jugs.
- Chocolate milk provides all the good nutrition of white milk and the same 16 nutrients. A deliciously satisfying drink, its ingredients are basically fresh milk, cocoa and sugar.
- Buttermilk is fresh milk with an added bacterial culture (similar to yogurt) that gives it a tangy flavour and thick, rich texture. Buttermilk adds tenderness to baked goods, and a light, tangy flavour to soups and salads.
- Calcium Fortified Milk Beverage: Regular milk to which calcium is added, in addition to its natural calcium. While regular milk is a tasty and nutritious choice, calcium fortified milk beverages can help people meet their calcium requirements if their intake is inadequate.
- Filtered Milk: Regular milk passed through fine filters to remove most microorganisms, making it seem creamier.
- Lactose-Free Milk: Regular milk that has been processed to break down lactose (sugar) in milk to help people with lactose intolerance to easily digest milk.
- Milk with DHA: Milk that comes from cows that are fed a conventional diet that has been enriched with DHA, a type of Omega-3 fat, from natural sources. This enriched diet allows cows to produce milk that is naturally higher in DHA (docosahexaenoic acid), which supports the normal development of the brain, eyes and nerves.
- Omega-3 Milk Beverage: Regular milk with added ingredients, such as flax oil, which add Omega-3 polyunsaturated fatty acids.
- Organic Milk: Milk from cows that are fed crops that are organically grown. Regular and organic milk are equally safe and nutritious.
- Prebiotic Fibre Milk Beverage: Regular milk with prebiotic fibre added. Prebiotic fibre promotes and enhances the activity of beneficial bacteria that naturally inhabit our digestive tracts and help us to digest foods and keep our bodies healthy by controlling harmful bacteria and other microorganisms.
- Probiotic Milk Beverage: Regular milk with added probiotic culture (bacteria that have an effect on health).
- Evaporated Milk: About 60% of the water is evaporated from fresh skim, 2% or whole milk. The high temperature needed to sterilize the milk causes a browning reaction to occur, giving this milk a slightly darker colour. Evaporated milk is sealed into cans and is heat tolerant, making it excellent for baked goods and slow-cooker recipes.
- Sweetened Condensed Milk: Made commercially by condensing milk to one third of its original volume and then adding sugar. Sweetened condensed milk is very thick and sweet and is available in cans. It is most often used in sweet baked goods; it is not interchangeable with other types of milk.
- Powdered Milk (Skim or Whole Milk Powder): Partly evaporated milk is heated and dried instantly. Powdered milk is made from whole or skim milk and is available in bags and in bulk. There are instant and regular formulas. Once the package is opened, it should be used within one month. This is whole milk with from which the water is removed by either spray drying or by roll drying processes.
- UHT Milk: Sterilized milk that has been heat-treated at an ultra-high temperature (138 to 158°C). Once it has cooled down, the milk is poured into a sterilized package without air contact, usually a Tetra Pak type box. Unopened, UHT milk keeps for several months at room temperature. Once opened, it must be refrigerated and consumed within 3 days.
Cream is the butter fat content of whole cow’s milk, separated from the water.
- Single Cream: contains not less than 18% butterfat. It cannot be whipped due to their being too little butterfat.
- Double cream: contains not less than 45% butterfat. It can be whipped but not too much as it will turn to butter. It can be used to enrich sauces, but may curdle if boiled along with acid ingredients.
- Whipping Cream: contains not less than 38% butterfat. It is perfect for whipping as its name indicates. After whipping you will find a difference in texture and a change in volume. Sweetened or unsweetened cream can be used in desserts or can be used as an accompaniment, and is incorporated in mousses to lighten them.
- Clotted Cream: contains not less than 55% butterfat. It is already very thick so it can be used as it is and not whipped.
- Soured Cream: These are single creams which contain about 20% butterfat, but have a souring culture in them, and they are matured.
- Half and Half: is a mixture of milk and cream in equal quantities and contains about 10-12% butterfat.
Curds are a dairy product obtained by curdling (coagulating) milk with rennet or any edible acidic substance such as lemon juice or vinegar, and then allowing it to set.
The increased acidity causes the milk proteins (casein) to tangle into solid masses, or curds. The remaining liquid, which contains only whey proteins, is the whey. In cow’s milk, 80% of the proteins are caseins. Milk that has been left to sour will also naturally produce curds, and sour milk cheese is produced this way.
In the Indian subcontinent, the word “curd” is widely used to refer to what is known as “yogurt”, but it appears to be a misnomer in the opinion of many. In India, another word “paneer” is used to denote the dairy product discussed in this article.
Cheese is a food derived from milk that is produced in a wide range of flavors, textures, and forms by coagulation of the milk protein casein. It comprises proteins and fat from milk, usually the milk of cows, buffalo, goats, or sheep. During production, the milk is usually acidified, and adding the enzyme rennet causes coagulation. The solids are separated and pressed into final form. Some cheeses have molds on the rind or throughout. Most cheeses melt at cooking temperature. (Read More About Cheese)
Yogurt, yoghurt, or yoghourt is a fermented milk product produced by bacterial fermentation of milk. The bacteria used to make yogurt are known as “yogurt cultures”. Fermentation of lactose by these bacteria produces lactic acid, which acts on milk protein to give yogurt its texture and its characteristic tang. Worldwide, cow’s milk, the protein of which mainly comprises casein, is most commonly used to make yogurt, but milk from water buffalo, goats, ewes, mares, camels, and yaks is also used in various parts of the world.
Yogurt is nutritionally rich in protein, calcium, riboflavin, vitamin B6 and vitamin B12. It has nutritional benefits beyond those of milk. Lactose-intolerant individuals can sometimes tolerate yogurt better than other dairy products, because the lactose in the milk is converted to glucose and galactose, and partially fermented to lactic acid, by the bacterial culture.
Reference: http://www.dairygoodness.ca/; http://en.wikipedia.org/wiki/Milk