Originally the heat treatment of milk was carried out primarily to improve the keeping qualities of raw milk so as to permit transportation in bulk over comparatively long distances with a minimum of loss due to spoilage. Only later with the realization that pasteurization was effective in destroying pathogenic organisms which might be present did the public health aspects of pasteurization assume their present importance.
The question is sometimes raised as to whether or not pasteurization entails any considerable sacrifice of some of the important nutritive properties of milk. A review by Kay1 presents some observations on this aspect of pasteurization. Recent well controlled investigations carried out by different workers on the comparative nutritive value of raw milk and pasteurized milk when fed to calves have shown that little difference exists between the two types of milk. In these studies not only rate of growth, physical condition and bodily