HEATING OF MILK

Hawke's Bay Tribune, Volume XXIII, Issue 81, 17 March 1933, Page 13

HEATING OF MILK

EFFECT ON DIETETIC VALUE. I'or several years the National Institute for Research in Dairying has been experimenting at the Reading University in England o n the relative values of raw and “heated” milk from the point of view of nutrition. Some of the experiments have been conducted with rats, comparable groups of which have been kept, under uniform conditions, and given diets similar in all except the type of milk. One group of rats has been fed on raw milk, another on pasteurised, and a third on “sterilised” milk. They have all been weighed and examined at frequent intervals, and their rate and condition of breeding have been studied and carefully recorded. “We shall not be in a position to lay down any definite opinion for some considerable time yet,” one of the directors said recently. r ‘Our results, when they are published, must bo such, as to satisfy the most exacting statistician. The experiments must be continued through several generations of rats. It is obvious that the heating of milk, a process which is carried out during pasteurisation, has some effects on the nutritive value, as well as reducing the bacteria content. Any attempt, therefore, to make the pasteurisation of all milk compulsory would, in our opinion, be extremely undesirable, until there is full knowledge as to the nutritional value of milk which has been pasteurised. ’ ’

The Manchester City Corporation is seeking Parliamentary powers to enforce the sale of none but Grade A (tuberculin tested) or pasteurised milk within 11»: city area. The section in Ww Utanebeetar Bill aokutg foe tUrtM

powers was expected to meet with considerable opposition from a variety of interests when it comes before Parliament early this year. The progress of some of the experiments at the Reading Institute has been described in technical journals such as the “Lancet.” One article, published in March, 1931, and signed by Dr. Elfreida C. V. Mattick and Mr J. Golding, of the Reading Institute, stated: “Our results show definitely that some dietetic factors are destroyed when milk is sterilised and to a definite but lesser degree when it is pasteurised, and that, although . . . fresh milk is capable of supporting sustained growth and reproduction in rats, heated milk is no longer capable of doing so.” The experiments with sterilised milk showed rapidly and conclusively that rats could not be sustained on this food for long, and that their reproductive faculties were seriously affected. The station was lately rearing a seventh generation of rats fed on raw milk. The only other food available throughout the experiments has been biscuits made from ■white English flour and water. The summary of the results up to March, 1931, stated; “Raw milk with biscuits made only of white flour and water, is capable of sustaining the growth and reproduction of rats Preliminary experiments with pasteurised milk demonstrate results sufficiently marked to indicate that milk heated at a temperature of 145 T» degrees Fahrenheit for half an hour has undergone changes which considerably reduced its dietetic Milne. . , . "