The effect of heat,age and reaction on the antiscorbutic potency of vegetables

Abstract

The present communication is a continuation of experiments on antiscorbutics previously reported. 1 It was found that it required 35 gms. of the carrots used to feed our laboratory animals, to afford protection against scurvy to a guinea-pig. After the carrots had been cooked for three quarters of an hour, their addition to the dietary proved insufficient to protect. This was true even if the water in which they were boiled had been acidulated by the addition of 10 per cent. of vinegar. The only difference noted in the latter test was a less marked loss of weight.

A parallel test was carried out with carrots which had been picked only a few days previous to the experiment. It was found that, even subsequent to cooking, 35 gms. of these fresh carrots, when added to the dietary of hay, oats and water, were fully capable of protecting the animals. It is evident, therefore, that, in a consideration of vegetables as a foodstuff, we must take into account the factor of freshness. In dietetics this difference is intensified by the fact that older vegetables are tougher and therefore require and receive more prolonged cooking, thus further lessening their antiscorbutic value. The water in which the vegetables were cooked possessed little or none of the accessory factor, although 40 c.c. per capita were fed to the guinea-pigs; the animals did not, however, lose weight as rapidly as those receiving tap water.

In a previous communication it was shown that 5 c.c. of cannedtomatoes is sufficient to protect a guinea-pig from scurvy. If such tomatoes are boiled for five minutes, their potency is slightly diminished, so that they should not be subjected to cooking when employed as an antiscorbutic for infants.