Definition Of Milk, Type And Nutrient Value In Diet

Definition: 

Milk is whitish liquid containing protein, fats, lactose, various vitamins and minerals that is produced by the mammary glands of all mature female or nourish their young for a period of beginning immediately after birth. It is the primary source of nutrition for young mammals, including breastfed human infants before they are able to digest solid foods. Milk has been used by human since the beginning of recorded time to provide both fresh and storable nutritious foods. In some countries almost half the milk produced is consumed as fresh pasteurized whole, low fat or skim milk.

How ever most milk is manufactured into more stable diary products of world wild commerce, such as butter, cheese, dried milk, ice cream, and condensed milk. Milk and any of the foods made from milk are referred to product of milk.

Nutrients Composition of Milk.

• Water: 87%.
• Protein: 3.5% (casein and whey).
• Fats: 3.5-3.7%.
• Carbohydrates: 4.9% (lactose).
• Vitamins: A, B6, B12, C, D, K, E, thiamine, niacin, biotin, riboflavin, folate and pantothenic acid.
• Minerals: Ca is present as calcium caseinate, calcium phosphate and calcium citrates.
• Other minerals: Chloride, magnesium, potassium, sodium and sulfur.
• Enzymes: Lipase, proteases, peroxidase.

Examples Of Milk And Milk Products 

• Raw milk.
• Whole milk.
• Dry milk.
• Evaporated milk.
• Condensed milk.
• Fortified milk.
• Flavored milk.
• Organic milk.
• Skim milk.

• Raw milk: This is an unpasteurized milk straight from cow.

• Whole mill: This is the milk from which no constituent is removed.

• Dry milk: This is a dehydrated milk from which 95% of water is removed.

• Evaporated milk: Evaporated milk is also a dehydrated milk by which 60% of water is removed.

• Condensed milk: Is an evaporated milk with sugar added.

• Fortified milk: These are milk enrich with one or more nutrients.

• Flavored milk: This is a sweetened drink made with milk, sugar, coloring and artificial flavoring added to it in order to give give it a good taste and good looking.

• Organic milk: These are milk that comes from cow. Organic milk is produce by diary farmers that use only organic fertilizers and organic pesticides, and their cows are not supplemental hormones.

• Skim milk: These are milk in which all cream has been removed. Skimmed milk has a fat content of between 0.1-0.3%.

Examples Of Milk Products

1. Fermented milk products.
2. Non fermented milk product.

Types Of Fermented Milk Products 

• Butter.
• Yoghurt.
• Ghee.
• Cheese.
• Buttermilk.

Butter: This is a concentrated form of fluid milk produce through churning of cream. It is mad from sweet or sour cream. Milk is churned to form butter and the watery buttermilk. Butter may have a yellow color due to fat soluble animals, pigment, carotene, or an additive.

Yoghurt: Yoghurt is a food produced by bacterial fermentation of milk. The bacteria used to make yogurt are known as yogurt cultures. Fermentation of sugars in the milk by these bacteria produces lactic acid, which acts on milk protein to give yoghurt its texture and characteristic tart flavor. Whole low fat skim milks and even cream can be used to make yoghurt. In production of yoghurt, a mixed culture of streptococcus thermophilus, lactobacillus acidophilus is usually added to the pasteurized milk and incubated at 42-46 degree centigrade.

Ghee: It is a type of clarified butter, it is prepared by simmering butter and removing the residue. The texture, color and taste of ghee depends on the quality of the butter and the duration of the boiling milk.

Cheese: These may be the most popular fermented milk product cheese is produced throughout the world in wide range flavors, textures, and form. Cheese consist of protein fats from milk, usually  or commonly the milks of cows, buffalo, goat or sheep etc. And it is produced by coagulation of the milk protein casein. 

Types Of Non Fermented Milks

• Skim milk.
• Evaporated milk.
• Sweetened milk.

Skim Milk:

Fat content is reduced to 0.5-2 per cent by centrifugation. By removing fat from the milk not only taste or flavor is reduced but fat-soluble-vitamins like vitamin A and D are deducted. Normally this milk is fortified with vitamins A and D. Condensed skim milk finds extensive use in the baking industry and manufacture of confectionery. Skim milk is normally used for low calorie diets and for children who need high protein.

Evaporated milk:

This is type of milk by which about 50-60% of the water has been evaporated. Raw milk is concentrated in a vacuum pan at a standard temperature of 74-77°C. It is fortified with vitamin D, homogenized, sterilized in cans at a temperature of 118°C for 15 minutes and cooled. This heat treatment gives evaporated milk a light brown color owing to sugar protein interaction and its characteristic flavor. As per PFA rules, the condensed milk should contain 26 % milk solids of which 8% is fat.

Sweetened condensed milk:

Sweetened condensed milk unlike the evaporated milk is not sterile. Multiplication of micro-organisms in the product is prevented by the preservation action of sugar. The product is made from pasteurized milk that is concentrated and sweetened with sucrose. Sugar concentration is 65%. This milk cannot be substituted for the ordinary fresh milk for children. As per PFA rules, the milk solids should be about 31% of which 9% is fat.