Milk

Milk:

is one of the most basic of all food. Milk constitute a complete diet and even for adults, cow’s milk includes many essential nutrients particularly calcium.

SOURCE

Mankind from time immemorial has used the milk of animals. The milk of cow, buffalo and goat is generally used. In some countries, milk of sheep, mare and camel is also used.

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.

COMPOSITION

Whole milk – that is, milk comes from the cow- is composed of water ( 88%), milk fat ( 3.25 %),  other milk solids( protein, lactose and minerals)- 8.25%.

There are many types of milk consumed though mostly it is cow’s milk, goat’s milk and sheep’s milk.

HISTORY OF MILK

Milk can be defined as a white opaque slightly sweet nutritious liquid secreted by the mammary glands, Milk has always been a symbol of fertility and wealth since biblical times and the promised land was described to be flowing with milk and honey.  In India and Asia, zebus and water-buffalo’s milk were considered sacred while the Romans and the Greeks were partial to the goat’s and ewe’s milk they also drank mares, camels, and asses milk.

Milk has a flourishing population of microbes. This is vital for natural coagulation of milk, but it can be harmful that is why various methods are used to pasteurize or sterilize the milk, thus avoiding deterioration and prolonging the length of time it can be stored.

TYPES OF MILK

1.Pasteurized milk:

  • Milk is heated to 71.7 degree C to crease bacteria growth and then cooled immediately.
  • It contains around 3.9% fats. Most commercial milk and cream are pasteurized.

2.Homogenized milk:

  • In this type of milk fat molecules remains suspended in the milk or cream.
  • This is done by forcing the milk through a series of extremely small holes to separates the fat particles into small pieces.
  • So that they resultant milk does not readily separate. It gives a better quality to use.

3.UHT (Ultra Heat Treated):

  • Homogenized milk heated at 172 degree C for 1 sec and then packed in sterilized conditions.
  • It is also bacteria free milk.

4.Sterilized milk:

  • Homogenized milk which is boiled at 115 degree C to 130 degree C and stored at 50 degree C. it is done to make the milk bacteria free.

5.Fortified milk:

  • Milk with addition of vitamins A and D, and others extra non fat solids.

6.Skimmed or non fat milk:

  • it has a most or all of the fat removed from the milk.
  • It contains 0.5 -2% fat. However it can’t be a substitute for whole milk in the making of the soup, sauce, dessert and others culinary preparations.

7.Flavored milk:

  • this type of milk is added with a distinguish flavoring ingredient like coffee, chocolate, vanilla, cardamom, strawberry etc. they are available in commercially ready to use packs or bottles.

8.Condensed milk:

  • The milk boiled and reduces till it achieves the thick consistency usually one third.
  • It contains maximum percent of milk solids.

9.Dry milk powder:

  • it contains all the necessary milk solids and contents. It has 5% of moisture in it.
  • It is the costliest one from all the above mentioned types of milk.

PASTEURIZATION PROCESS/STEPS

  • Milking is done twice a day, the process is mechanical in big farms. Temperature and taste of the milk is checked at this stage
  • The milk is transferred to large refrigerated tanks in which it is transported to the processing units through huge trucks.
  • Separation and clarification of the milk takes place in separators to separate milk from germs and useless remains.
  • Fortification of milk with minerals and vitamins takes place after separation and clarification
  • Pasteurization of the milk takes place which involves heating the milk to kill harmful microorganisms
  • Homogenization removes fat from the milk
  • Milk is then packed in cartons or plastic covers. Labelling is done with the expiry date and the packs are distributed to different states
  • Pasteurization refers to the process of heating a liquid to below the boiling point to destroy microorganisms.
  • The process was named after its developer, Louis Pasteur who implied it initially to improve the keeping quality of the wine.
  • The main motto behind pasteurization was to control tuberculosis causing bacteria, which is no longer a concern as cows are tested for TB annually and removed from herds and treated if shown positive.