Nutritional information
The ‘Milky Way’ to good health!
Milk is an important component of a balanced diet. It is considered one of the world’s most ‘complete’ foods and the richest dietary source of calcium. The nutrients in dairy foods can help to prevent dental cavities, osteoporosis, high blood pressure, stroke and kidney stones. Milk contains over 10 essential nutrients:
Calcium
Strong bones and teeth. Muscle function.
Osteoporosis prevention.
Carbohydrate (Lactose)
Fuel for the body. Assists growth and vitality.
Magnesium
Muscular function. Energy transfer within body.
Phosphorus
Strong bones and teeth. Release of energy.
Potassium
Blood pressure control, muscle and nerve function.
Protein
Growth and development. Muscle strength. Healing wounds.
Riboflavin (Vitamin B2)
Growth. Healthy eyes and skin.
Vitamin A (Retinol)
Immune function. Healthy eyesight and skin.
Vitamin B12
Brain and nerve function. Production of red blood cells.
Zinc
Immune function. Growth and development.
These days, new beneficial components of milk are being discovered, such as whey protein, sphingomyelin and conjugated linoleic acid. Now there are even more reasons to enjoy a glass of milk!
Proximate Composition of Some Australian Milks
Type per 100g
| Protein (g)
| Fat (g)
| Carbohydrate (g)
| Energy (kj)
| Calcium (mg)
|
|---|
Regular
|
3.3
|
3.8
|
4.7
|
271
|
114
|
UTH / Longlife
|
3.5
|
3.7
|
4.6
|
272
|
117
|
Skim
|
3.6
|
0.1
|
5.0
|
144
|
123
|
Reduced Fat (modified milk)
|
3.9
|
1.4
|
5.3
|
204
|
137
|
Low Fat (modified milk)
|
4.6
|
0.2
|
6.5
|
187
|
160 |
Milk Composition
Milk is composed of:
- Water 87.6%
- Carbohydrates 4.7%
- Fat 3.8%
- Protein 3.3%
- Vitamins and Minerals 0.6%
Source: Proximate composition of Australian Dairy Foods, 1999.
What Makes Milk White?
Casein (milk protein) is present in the form of very small complexes which reflect light, giving milk its whiteness.
Milk composition varies throughout the year due to the quality of feed available and weather conditions. However, these variations are usually standardised during processing.
Technology, Management and Methods
Today’s technological farming methods, cattle management and factory methods give more control and therefore more consistency in milk production. Cows on irrigated pastures will produce milk with the most consistent composition.
Milk composition can be adjusted using today’s technology. Special varieties of milk require adjustment to either reduce fat levels or increase nutrient content. The following methods also assist in standardising the milk composition for year round consistency, although regional differences may still occur.
Centrifugal Separation
Removes some or all of the cream to produce reduced fat, low fat or skim milk. Skim milk solids may then be added to retain taste and increase the level of important nutrients such as protein and calcium. These additions make the flavour and mouthfeel of the milk more appealing.
Ultrafiltration (UF)
Pumps milk across a membrane under moderate pressure. This process holds back the protein and fat globules, together with a high proportion of the valuable calcium complexes, while allowing some of the water and lactose to pass through. The result is a product enriched in protein and calcium with a fat content adjusted to suit the consumer.
Reverse Osmosis
A similar process to UF, however the membrane holds back nearly all the milk solids and only allows water to pass through. Note that lactose is retained in this process. There is no impact on flavour.
Ultra Osmosis
A hybrid of the previous two processes, it holds back milk solids but allows water and salt to pass through.
Spray Drying
Removes the remaining water from milk to create powdered milk products. The high nutritional value of the milk product is unimpaired.