About commercial milk
Many types of milk are sold in the market nowadays: homogenized, pasteurized... Here you can understand what all those names mean.
- Homogenized: Milk is an emulsion which contains droplets of fat dispersed in a mixture of water, sugars and proteins. In the homogenization process the milk is forced through tiny tubes under pressure, so fat particles are broken up and dispersed evenly. Then the cream will not separate out upon standing. Here you can find more information.
- Pasteurized: This milk has been treated to destroy potentially harmful bacteria. Pasteurization consists on heating milk to at least 72°C for about 16 seconds or 65°C for 30 minutes. This process increases also the shelf life of milk up to 15 days. More information here.
- Ultrapasteurized (UHT): This milk is processed at higher temperatures (usually 140-150°C for 1-2 seconds). It is packed in presterilized brick-style cartons and can be stored without refrigeration for about six months.
- Skimmed: This kind of milk is prepared by removing the fat from whole milk by using a cream separator. Vitamin A and other fat-soluble vitamins are removed also in the process, so this form is not preferred for infants and young children. Since the fat is removed it is suitable for many therapeutic conditions like, diabetic, obesity, high cholesterol, heart diseases, hypertension etc. Sometimes those fat-soluble vitamins are added at the end of the process, so that enriched skimmed milk will have more or less the same nutritional properties as whole milk.
- Evaporated: Half of the milk’s moisture is removed by evaporation before it is canned. Then this milk can be kept at room temperature for up to six months.
- Sweetened condensed: This type of canned milk is also made by removing half of the water from whole milk, but then it is highly sweetened. As a result this milk is very high in calories.
- Powdered: To make this product, some of the water is evaporated and then the milk is sprayed into a drying chamber to further reduce its moisture content, resulting in milk powder. The powder can be easily reconstituted for use by adding water.
Of course it is healthy to drink milk, but the commercial milk is not the same after those processes. At least we should know it when we drink it.