VITAMIN C 195 



be expected to vary considerably in their content of antiscorbutic vita- 

 min according to their freshness and age. While young carrots v^ere 

 much superior to old carrots in antiscorbutic value, he found that 

 slightly green tomatoes contained less antiscorbutic vitamin than did 

 those which were fully ripe. So far as fruits and vegetables are con- 

 cerned, our present limited knowledge would seem to suggest that the 

 degree of maturity at which the fresh food is most prized will prob- 

 ably approximate that at which it has greatest vitamin value. 



Dried carrots were found by Hess and Unger to have lost anti- 

 scorbutic vitamin to a serious extent but not necessarily entirely. In 

 the quantities which they fed, the carrots which had been allowed to 

 age before drying, failed after drying to prevent scurvy, whereas 

 protection was afforded by an equal amount of carrot which had been 

 quickly dried when young and fresh. 



The emphasis laid by Hess upon the importance of the time factor 

 in problems connected with the destruction or conservation of anti- 

 scorbutic vitamin will be discussed in connection with other experiments 

 to be described beyond. 



Potatoes while containing the antiscorbutic vitamin in distinctly 

 lower concentration than do oranges, lemons and tomatoes, are yet of 

 great importance as antiscorbutics because of the quantities in which 

 they are consumed. Hess (1920) estimated that in the countries of the 

 temperate zone the consumption of potatoes is probably twice that of 

 all other vegetables combined and that for this reason our protection 

 from scur\y actually rests very largely upon the potato. "Therefore if 

 this crop fails scurvy will develop in the spring." Weight for weight, 

 cooked potatoes are comparable as antiscorbutics with apples and 

 bananas and have only around one-fourth of the concentration of 

 vitamin C which we find in oranges, lemons and tomatoes. 



Givens and Cohen (1918) reported a number of experiments with 

 potatoes cooked in different ways and in some cases dried before feed- 

 ing. From the variable results obtained the authors were led to suggest 

 the possibility that the factors involved in the destruction of the anti- 

 scorbutic vitamin are not only the degree of heat and the duration of the 

 heating but also the enzyme content and the reaction of the food being 

 dried. By employing a high temperature for a short time, as in the 

 case of baked potatoes, the enzymes are destroyed, while at any tem- 

 perature below 80° C. enzymes may still function and probably play 

 an important role in the destruction of the antiscorbutic vitamin. (It 

 is presumably the oxidizing enzymes that would be chiefly destructive 

 of vitamin C.) 



