Pasteurization of Milk
In pasteurizing milk it is heated to a temperature of 60° C. (140° F.) for a period of twenty minutes. This destroys the so-called pathogenic germs, yet does not destroy the ordinary milk ferments. It does not change its digestibility nor alter the taste or appearance.
All of the so-called pathogenic germs, such as tuberculosis, typhoid, dysentery and diphtheria, for example, are completely destroyed by pasteurization, but the ferments are not destroyed and the milk is in no way altered. This process may be accomplished on a large scale and thus furnish as safe milk for commercial consumption. Pasteurized milk should be rapidly cooled after heating, and if kept cool furnishes a clean, healthy milk entirely safe and satisfactory for infant food as well as for adults.
Pasteurization furnishes a purified milk but not a pure milk. It is undoubtedly the best means of preservation and may be considered as bearing the same relation to purification of milk as filtration bears to purification of water.
The use of formaldehyde, borax and boracic acid is as objectionable in artificial preservation of milk as in the preservation of meat and other foods and should not be tolerated.