Milk & Cream : Meaning, Types, Uses

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 promise 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 detoriation and prolonging the length of time if can be stored.

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 detoriation and prolonging the length of time if can be stored.

PROCESSING TECHNIQUES:

From the time it is milked from the animal to the time of sale, milk has to undergo processing to improve the keeping quality and to make it fit for consumption. The various stages are:

1. Collection

Milk is brought to the dairy in clean sterilized vessels, preferably stainless steel.

2. Holding tanks

The milk is immediately transferred to holding tanks and is held at 10°C to keep it safe. Cooling is done either in a tank, jacketed with pipes in which runs a brine solution. Else the milk is run over very cold water pipes.

3. Filtration

The milk is passed through a series screens and filters to remove sediment and floating particles.

4. Pasteurization

It is the process of heating milk to 63.7°C and holding it at that temperature for 30 minutes. This is known as the “Holder Process of Pasteurization”. Nowadays, the Flash Pasteurization is more commonly used. It is also called the HTST or High Temperature Short Time method, where the milk is heated to 71.6°C for only 15 seconds. Pasteurization makes milk safe for human consumption by destroying pathogenic germs (pathogens). It also helps to increase the shelf life. Flavour of the milk remains unaffected at pasteurization temperature.

5. Homogenization

At temperature of 60°C, milk is passed under high pressure through small opening of a machine called homogenizer. The main purpose is to subdivide the fat globules in milk and disperse them evenly in the entire mass. Fat has a low density and tends to rise to the surface during heating. Homogenization prevents this by first breaking up the fat into tiny particles and then dispersing them throughout the milk. This adds to the flavour and results in a better body.

6. Bottling

The bottles of selected and uniform size have to be sterilized by steam and hot water and then they are filled with milk, which are capped automatically. Nowadays milk is filled in plastic pouches and these are more economical, easily transported and save storage space. Plastic pouches are easily disposed and are safe to handle.

7. Sterilization

The sealed bottles are now heated for 30 to 40 minutes at temperatures ranging from 104-110°C in steam chambers called autoclaves and then allowed to cool. Milk can also be sterilized before bottling. It is subjected to temperatures of 135-150°C for just 1 second. This is called the UHT or Ultra Heat Treatment. This process kills off all microorganisms and the very short holding temperature reduces the changes in colour and lined with aluminum foil. Milk is then distributed through various outlets.

Various types of milk:

1. Untreated milk: it retains its entire natural flavor. It is advised to boil for 15 minutes before using. It remains good in refrigerator for 24 hrs.

2. Pasteurized milk: To kill bacteria by heating milk or other liquids to moderately high temperatures for a short period of time. Milk must be heated to at least 145°F for not less than 30 minutes or at least 161°F for 15 seconds, and then rapidly cooled to 40°F or lower.

3. Sterilized milk: is homogenized milk, heated to about 112ºC under pressure for 15 mins in sealed bottle. The bottle is rapidly pulled to 80ºC and then allows reaching lower temperature.

4. Skimmed milk: this is the milk without any fat. Basically it is a fat buster, low calorie produce

5. Fortified milk: extra nutrients are added to make the milk more nutritive. Usually vitamin B is used.

6. Flavored milk: flavor and color added. Treated with high temperature of 100ºC for about 15 mins, so that they may be kept later at room temperature.

7       Untreated milk: it retains its entire natural flavor. It is advised to boil for 15 minutes before using. It remains good in refrigerator for 24 hrs.

8  Pasteurized milk: To kill bacteria by heating milk or other liquids to moderately high temperatures for a short period of time. Milk must be heated to at least 145°F for not less than 30 minutes or at least 161°F for 15 seconds, and then rapidly cooled to 40°F or lower.

9  Sterilized milk: is homogenized milk, heated to about 112ºC under pressure for 15 mins in sealed bottle. The bottle is rapidly pulled to 80ºC and then allows reaching lower temperature.

10  Skimmed milk: this is the milk without any fat. Basically it is a fat buster, low calorie produce

11  Fortified milk: extra nutrients are added to make the milk more nutritive. Usually vitamin B is used.

12  Flavored milk: flavor and color added. Treated with high temperature of 100ºC for about 15 mins, so that they

may be kept later at room temperature.

TONNED MILK : toning is done to make buffalo milk resemble in appearance and flavor to cow’s milk. It is done by dilution and addition of skimmed milk powder. 40 % of skimmed milk is added to 60 % of buffalo milk. The addition of skimmed milk powder makes up for the dilution of the nutrients, the fat content remains diluted and equal to that of cow’s milk.

Concentrated milk:

·      Evaporated milk – unsweetened milk, evaporated under reduced pressure and reduced to 60% and canned.

·      Sweetened milk- same as above but sugar is added before processing. Sugar acts as preservatives also.

·      Milk powder-This is the whole milk from which the water is removed by either spray drying or by drying processes

CULTURED DAIRY PRODUCTS:

Cultured dairy products such as yoghurt, butter milk, and sour cream are produced by adding specific bacterial cultures to fluid diary products. The bacteria convert the lactose to lactic acid, giving the products their body, and tangy and unique flavor.

USES OF MILK

1)  Used in soups & sauces.

2)  Used in vegetables preparation.

3)  Used for making puddings, cakes & sweet dishes.

4)  It is used for the preparation of non-alcoholic drinks such as milk shakes

5)  Used in preparation of hot drink such as tea, coffee, hot chocolates etc. Notes :

WHOLE MILK: It comes as pasteurized & has fat content of 3.9 %.

CREAM

Cream is the butter fat content of whole cow’s milk, separated from the water.

Cream is commercially separated from milk in a creamery, by means of a mechanical separator. The milk is first heated to between 32-49°C (90-120°F) before being run into the separator which operates like centrifugal machine, rotating at very high speed and forcing the milk, which is heavier, to the outside; while the cream, which is lighter, remains at the centre. The cream and the skimmed milk are drained out through separate outlets and by means of a control valve, the fat content is adjusted. The skimmed milk is then heated to 79.5°C (175°F) to kill off any harmful bacteria before being further processed into dried milk etc.

The principal difference between the various types of cream -single cream, double cream, whipping cream, clotted cream and soured cream - is the balance between water and butterfat. This will make them liquid or of a very thick consistency.

Other differences are in the way they have been made and their time for maturing which results in different tastes.

Cream has a slight yellow or ivory color and is more viscous than milk.

Cream is used in kitchen to give flavor and body to sauce, soups and desserts.

Types of Cream

1. Single Cream: contains not less than 18% butterfat. It cannot be whipped due to their being too little butterfat.
2. 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.
3. Whipping Cream: containing 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. 
4. Clotted Cream:  contains not less than 55% butterfat. It is already very thick so it can be used as it is and not whipped.
5. Soured Cream: These are single creams which contain about 20% butterfat, but have a souring culture in them, and they are matured.
6. Half and Half: is a mixture of milk and cream in equal quantities and contains about 10-12% butterfat.

Note: Cream should be whipped at around 4ºC. And for this it will be helpful to chill the bowls also so as to allow little dissipation of heat.

Manufacture Cream 1. Reconstituted Cream

It is made by emulsifying butter with skimmed milk or skimmed milk powder. This is not true cream, but a substance which resembles it in appearance.

2. Imitation or Synthetic Cream

It is made by the emulsification of vegetable fats with dried egg and gelatin, and then sugar and flavourings are added. It is a product which is frequently used in catering and baking trade, but which is very easily contaminated and liable to cause food-poisoning.

Uses of Cream

1.  To serve with hot or cold coffee and chocolate.

2.  To serve as an accompaniment (fruit based salad).

3.  To be used fro decorative purposes in cakes and gateaux and for garnishes in soups and desserts.

4.  As a main ingredient in certain desserts such as ice-cream and custards.

 Storage of Cream

Fresh cream must be treated in the same way as fresh milk, as far as storage is concerned. Whipped cream must be covered and stored in sterilized containers in the refrigerator and used in the same day. Reconstituted and intimation cream must be refrigerated and only small quantities be whipped, when required for immediate use.