Milk is important as a food among animal and vegetarian foods that provides essential nutrients for our body.Mammals depend entirely on milk in their early stage of life.
Moreover, it can be considered as a natural drink suitable for everyone including young, elder and ill persons because of its liquid form and easily digesting nature.
Other products of milk are also important because of their nutrients and some milk are easily digestive than fresh milk.
Fresh cow milk has its unique taste, smell and colour. They are caused by proteins, calcium, and salt dissolved in milk. There are various factors for milk to be popularized as a food.
1. Substitution for breast milk for infants
2. A nutritious food for growth of children
3. People are used to drink milk for ages and appreciate its freshness and taste.
4. Various new products that are produced with modern technology.
5. Milk products can be kept for a relatively longer period
Composition of milk
Milk consists less than 8.3 percent of solid particles, and fat less than 3.36 percent.
Milk contains Carbohydrate, lipids, proteins, minerals, vitamins, and enzymes. Carbohydrate is mainly composed of lactose and protein is comprised of casein, albumin and globulin.
Casein is easily digested and when boiled albumin and globulin are clabbered. Oil particles are mixed and compose the scum.
Comparison between breast milk and cow milk
Constituent breast milk Cow milk
Composition of milk
Milk consists less than 8.3 percent of solid particles, and fat less than 3.36 percent.
Milk contains Carbohydrate, lipids, proteins, minerals, vitamins, and enzymes. Carbohydrate is mainly composed of lactose and protein is comprised of casein, albumin and globulin.
Casein is easily digested and when boiled albumin and globulin are clabbered. Oil particles are mixed and compose the scum.
Comparison between breast milk and cow milk
Constituent breast milk Cow milk
Water 87.5 87.5
Protein 1.2 3.3
Lactose 6.9 4.6
Fat 3.8 3.7
Calcium 0.1 0.1
Milk production and its composition depend on various factors such as species and type of the animal, milking time, status of milk, climate and milking method and according to the milkmaid.
Importance of Calcium/Phosphorous ratio
Many foods contain more phosphorous than calcium but milk contains them in 1:1 ratio.
Vitamins - A,B,D,K
Cow milk is a good vitamin source that contains more B, D vitamins and less A, K vitamins.
Importance of milk in nutrition
1. Natural drink with many nutrients. Good for all age groups.
Milk production and its composition depend on various factors such as species and type of the animal, milking time, status of milk, climate and milking method and according to the milkmaid.
Importance of Calcium/Phosphorous ratio
Many foods contain more phosphorous than calcium but milk contains them in 1:1 ratio.
Vitamins - A,B,D,K
Cow milk is a good vitamin source that contains more B, D vitamins and less A, K vitamins.
Importance of milk in nutrition
1. Natural drink with many nutrients. Good for all age groups.
2. High calcium food that helps growth and gain energy.
3. It helps in preventing the lack of lysine, a kind of essential amino acids.
4. Its natural composition helps in absorbing many nutrients in foods.
5. It helps in getting the vitamin requirement which lacks in a certain meal.
Methods of preserving milk and its advantages and disadvantages
Milk is a good environment for the growth of microbes and hence it is easily spoiled. Therefore various methods are used to preserve them and all these methods emphasis following facts.
A Preserve its quality and prevent the penetration of harmful material
Methods of preserving milk and its advantages and disadvantages
Milk is a good environment for the growth of microbes and hence it is easily spoiled. Therefore various methods are used to preserve them and all these methods emphasis following facts.
A Preserve its quality and prevent the penetration of harmful material
B Preserve its freshness, nutrition and taste
C Cleanliness and freshness
D Not using artificial flavours and preservatives
There are three main preserving methods.
1. Thickening by boiling
There are three main preserving methods.
1. Thickening by boiling
2. Preserving by using healthy microbes
3. Cheese production.
Some of these methods help in preserving the product as well as easy digestion and absorption of nutrients.
Methods of preservation
Pasteurized milk
Pasteurization kills pathogenic bacteria by heat to preserve milk till its consumption.
There are two methods. They can be heated to 63 Celsius and kept in the same temperature for 30 minutes and should be immediately cooled to 4 Celsius.
This pasteurized milk can be kept for 48 hours in 20 Celsius and 72 hours in 15 Celsius. They should be kept in 10 Celsius till they are obtained by consumers.
Advantages of pasteurization
1. Preserve nutrients as it is not boiled to high temperature.
Some of these methods help in preserving the product as well as easy digestion and absorption of nutrients.
Methods of preservation
Pasteurized milk
Pasteurization kills pathogenic bacteria by heat to preserve milk till its consumption.
There are two methods. They can be heated to 63 Celsius and kept in the same temperature for 30 minutes and should be immediately cooled to 4 Celsius.
This pasteurized milk can be kept for 48 hours in 20 Celsius and 72 hours in 15 Celsius. They should be kept in 10 Celsius till they are obtained by consumers.
Advantages of pasteurization
1. Preserve nutrients as it is not boiled to high temperature.
2. Provides proteins and energy for growing children and adults.
3. Free of pathogenic bacteria
4. Can be kept for 72 hours in a refrigerator
5. Eases digestion.
6. Preserve natural taste.
Sterilized milk
Milk is boiled to 120 Celsius and should be bottled at a temperature of 60-70 and again boiled to 120 Celsius for 20-60 minutes to keep same temperature within bottles.
Advantages
1. Slight change in flavour.
Sterilized milk
Milk is boiled to 120 Celsius and should be bottled at a temperature of 60-70 and again boiled to 120 Celsius for 20-60 minutes to keep same temperature within bottles.
Advantages
1. Slight change in flavour.
2. Can keep for some period as all bacteria have been destroyed.
3. Protected from germs.
4. Not necessary to keep in refrigerator till opening.
5. No artificial flavours or preservatives.
Pasteurized and sterilized milk should be transported and stored as not to connect with sunlight as it could damage the nutrition of milk.
Condensed milk
Milk is heated to 80 Celsius for 15 minutes and adds sugar and condensed at a low pressure and sealed. They may be of low fat hence suitable for elder persons.
Advantages
1. Preserves taste, nutrition and healthiness
Pasteurized and sterilized milk should be transported and stored as not to connect with sunlight as it could damage the nutrition of milk.
Condensed milk
Milk is heated to 80 Celsius for 15 minutes and adds sugar and condensed at a low pressure and sealed. They may be of low fat hence suitable for elder persons.
Advantages
1. Preserves taste, nutrition and healthiness
2. Not necessary to keep in refrigerator till opening.
3. Easy to store and transport.
4. Free of chemical preservatives.
5. Provides proteins and energy for adults.
6. Can be used in preparing desserts.
Yoghurt/curd
Heat the milk after mixing with sugar. After it is cool add culture and keep 24-72 hours and yoghurt is made.
In Sri Lanka milk from both cows and buffalos are used for curd production and milk from buffalo has 7-9 percent fat which is more beneficial for production.
Curd is easily digestible than fresh milk and vitamins are absorbed more in curd including thiamine, riboflavin and vitamin E12, that improves the nourishment of curd.
It has been proved that curd has more capacity in absorbing nitrogen, calcium, phosphorous and iron.
Advantages
1. Eases the digestion.
Yoghurt/curd
Heat the milk after mixing with sugar. After it is cool add culture and keep 24-72 hours and yoghurt is made.
In Sri Lanka milk from both cows and buffalos are used for curd production and milk from buffalo has 7-9 percent fat which is more beneficial for production.
Curd is easily digestible than fresh milk and vitamins are absorbed more in curd including thiamine, riboflavin and vitamin E12, that improves the nourishment of curd.
It has been proved that curd has more capacity in absorbing nitrogen, calcium, phosphorous and iron.
Advantages
1. Eases the digestion.
2. Vitamins are absorbed effectively.
3. Improves nourishment with increased thiamine, riboflavin and vitamin E12.
4. Good appetizer for growing children.
Milk powder
There are several forms of milk powder.
1. Full cream
Milk powder
There are several forms of milk powder.
1. Full cream
2. Low fat
3. Non fat
There are two methods of preparing milk powder.
One is called 'spray drying'. Milk is sprayed into a huge chamber and heated air is blown from the other end. The droplets of the milk dry up very quickly in the hot air and fall down. The powder can then be scraped off and packed into jars or sachets.
Another way is 'drum drying'. In this, milk is sprayed onto huge drums, which are heated by electric current. The heat makes the water in the milk evaporate and the powder stays behind on the drum. Drum-dried milk is often flaky and sticky, while spray dried milk is powdery and non-sticky.
Composition of milk powder
In full cream milk powder there are 26.5% protein, 27% fat and 37.5% lactose.
There are two methods of preparing milk powder.
One is called 'spray drying'. Milk is sprayed into a huge chamber and heated air is blown from the other end. The droplets of the milk dry up very quickly in the hot air and fall down. The powder can then be scraped off and packed into jars or sachets.
Another way is 'drum drying'. In this, milk is sprayed onto huge drums, which are heated by electric current. The heat makes the water in the milk evaporate and the powder stays behind on the drum. Drum-dried milk is often flaky and sticky, while spray dried milk is powdery and non-sticky.
Composition of milk powder
In full cream milk powder there are 26.5% protein, 27% fat and 37.5% lactose.
In low fat milk powder there are 31% protein, 16.5% fat and 43% lactose.
Matters to be noted in consuming milk powder
A. Should be stored not to contact with air, or it will cause them to spoil.
Matters to be noted in consuming milk powder
A. Should be stored not to contact with air, or it will cause them to spoil.
B. Water ratio when storing should be less than 4% or it will cause changes in solubility, flavour and colour.
C. When milk [powder is produced vitamins A and D are removed with water and fat and some amino acids are destroyed due to heat.
Economic benefits of fresh milk use
Expenditure for a person to drink a glass of milk a day:
Economic benefits of fresh milk use
Expenditure for a person to drink a glass of milk a day:
General price of a glass of fresh milk - Rs. 50.00
Volume of a glass – 200 ml
No of glasses in a litre of milk - 5
Cost of a glass of milk - Rs. 10.00
Hence drinking fresh milk is economic than consuming other prepared products and cool drinks.
Advantages of promoting fresh milk
1. As fresh milk is more available in rural areas it will reduce malnutrition and generate a healthy society in those areas.
Hence drinking fresh milk is economic than consuming other prepared products and cool drinks.
Advantages of promoting fresh milk
1. As fresh milk is more available in rural areas it will reduce malnutrition and generate a healthy society in those areas.
2. Beneficial to producer when demand is increased.
3. Promotion of dairy farming as an additional income for farmers.
4. Save foreign exchange spent for importing milk related food.
5. Cost reduction for transportation, production and processing of milk.
This article is based on a publication by the Ministry of Livestock and Rural Community Development and Department of Animal Production and Health.
This article is based on a publication by the Ministry of Livestock and Rural Community Development and Department of Animal Production and Health.
