Russian doctor Osip Krichevsky
first produced powdered milk in 1802. It
is made by drying or dehydrating milk until it forms a fine white powder. This can be achieved either by spraying a
fine mist of milk into a heated chamber or by adding the milk in a thin layer
to a heated surface, from which the dried milk solids can be scraped off. Freeze-drying is now used because it
conserves more nutrition and the milk cane be fortified to improve its
nutritional value. The resulting powder
can then be stored for a long periods, because the dry environment means it is
less prone to bacterial contamination that
would spoil fresh milk.
As well as its potential for long
term storage, powdered milk has several practical advantages over fresh
milk. In the developing world, its
relative light weight and the fact that is does not need refrigerating mean
that it is easy to transport over long distances, without the need for
expensive refrigerated trucks.
Powdered milk has found an
additional use in modern science in a technique for separating proteins called
Western Blotting. In this process, the
protein rich milk is used to block inappropriate binding of the antibodies
used, and therefore produced a much clearer result experiments.
