Influence of Superheating on Antirachitic Properties of Irradiated Foods.

Abstract

There is some evidence that superheating destroys the antirachitic effect of irradiation. 1 In order to test this point further we have compared over a period of 10 weeks the growth performance of rats which were receiving a rachitic ration 2 with that of animals receiving (1) similar rations which had been irradiated; and (2) the irradiated ration which had been subsequently superheated. This rachitic ration which consisted of a mixture of grains was finely ground, mixed with distilled water and heated until it was of a thick gelatinous consistency. Since even at 15 pounds pressure mixtures of this consistency seldom reach throughout temperatures above 97° C., it was thought that results with these rachitic rations might not be valid. Therefore, we have tested the effects of the addition to the ration of (1) boiled milk; (2) irradiated boiled milk; and (3) irradiated milk which was subsequently autoclaved.

In order to test further the effect of superheating on the antirachitic properties of milk, we have used in the rachitic ration comparable amounts of evaporated milk, as well as evaporated milk supplemented with calcium phosphate, thereby ruling out the influence of the possible calcium deficiency of the evaporated milk.

The rickets ration was irradiated in thin layers (⅛ inch) for ½ hour at a distance of 2 feet. Part of this was then autoclaved at 15 pounds for 6 hours. The milk was irradiated in ¼ inch layers for 20 minutes at a distance of 2 feet. Before autoclaving this was diluted with distilled water and heated at 15 pounds pressure for one hour.

The results of the investigation indicate that superheating, at least to the extent involved in the experiment, does not affect the antirachitic properties of food. This is shown not only by the animals which received the irradiated milks, but by those receiving the evaporated milk as well.