The destruction of the antiscorbutic vitamin in milk by the catalytic action of minute amounts of copper

Abstract

In a previous communication 1 it was shown that the antiscorbutic vitamin in milk, orange juice, or tomato juice, is, to a certain extent, destroyed by oxidation. In view of the well-known action of catalysts in increasing oxidative processes, and the frequent presence of traces of copper in milk, it seemed worth while to ascertain the effect of the addition of small amounts of copper to milk. To this end two groups of guinea pigs were fed equal amounts of milk, which, in the one instance, had been heated in a glass vessel to 60° C. for 40 minutes, and, in the other instance, had been heated in a copper vessel to the same degree. Each animal received daily dried milk to the equivalent of 100 c.c. of fluid milk, and oats in addition. Diluted dry milk was employed, so as to be able to concentrate the milk and thus insure its complete consumption.

None of the guinea pigs fed on the milk heated in the glass vessel developed scurvy during a period of four months; they did not, however, make normal gains as the quota of antiscorbutic vitamin was inadequate. On the other hand, the animals fed with the same quantity of milk, which had been heated in a copper vessel, all developed scurvy, and died after about four weeks. This milk contained 1.4 part of copper per million. That this nutritional failure was due to a lack of antiscorbutic vitamin was demonstrated by the excellent gains of a third group of guinea pigs which were given milk which had been heated in the copper vessel, but received in addition 2 c.c. daily of orange juice.

Milk frequently becomes contaminated with copper in the course of commercial pasteurization or condensation.