Milk powder: which drying process
The manufacture of a milk powder consists in transforming the liquid milk into powder. This process generally involves 2 successive operations. The first is to concentrate the liquid milk by evaporating the water in a vacuum. The second step is to continue to remove the remaining water.
The condensed milk is finely sprayed through a turbine into a stream of hot, dry air (around 150 °C) inside a drying tower, which results in the evaporation of the water. This operation takes a few seconds.
Depending on the raw material used (full cream, semi-skimmed or skimmed milk), the milk powder will be full cream, semi-skimmed or skimmed. Dehydration does not alter the nutrients of the milk: calcium, protein, lactose, mineral salts and milk fat (if not skimmed) are contained in the resulting powder.
It is an effective way to store milk, easy to store and transport: powdered milk has the advantage of being shelf stable for several months at room temperature.
There are many types of dairy powders, including skimmed milk powder, full cream milk powder, whey powder, buttermilk powder and casein powder.
Various uses
The most common use of skimmed milk powder is for infant milk. This provides babies with the proteins necessary for their growth. The manufacture of infant formulas is subject to strict regulations.
Milk powders are also an ingredient used in the food industry (bakery, chocolate, delicatessen, formulated dishes, soups, sauces, etc.) for their texturising utility (foaming, emulsifying or thickening), and to improve the nutritional properties of various products thanks in particular to the proteins and minerals in milk.