184 THE VITAMINS 



tion with the drying process is the cause of their deficiency in vita- 

 min C. 



Harden and Robison (1919) showed that the antiscorbutic sub- 

 stance in orange juice is not volatiHzed nor largely destroyed when the 

 juice is distilled at 40° C. under reduced pressure. The solid residue 

 obtained by this process was found to have strong antiscorbutic prop- 

 erties which were not appreciably diminished on keeping the substance 

 in a dry atmosphere at room temperature for six months. Later tests 

 (1920, 1921) of the dried orange juice stored in a desiccator at room 

 temperature showed a gradual destruction of the antiscorbutic proper- 

 ties amounting to about 50 per cent in 15 months. 



Givens and McCkiggage (1919a) dried orange juice in two differ- 

 ent ways as follows: For one product, the juice was expressed from 

 the oranges and strained through several layers of cheesecloth until 

 a clear filtrate was obtained. This was concentrated to about two-thirds 

 the original volume by heating in a drier at from 55° to 60° C, using 

 100 cubic centimeter portions in small shallow dishes. Soy bean flour, 

 previously heated under 20-lbs. pressure for one-half hour, was then 

 added in the proportion of 12 grams to 100 cubic centimeters of the 

 original juice and mixed thoroughly. The mixture was kept in the drier 

 at from 55° to 60° C. until thoroughly dried, the whole process requir- 

 ing about 50 hours. For the other product, the juice was dehydrated by 

 a commercial process employed for making milk powder. The juice was 

 pressed from the oranges, strained, mixed with corn sirup, and dried 

 almost instantaneously by spraying into a chamber kept at from 

 75° to 80° C. In the case of the second product a dose equivalent 

 to 3 cubic centimeters of the fresh juice was sufficient to protect 

 a guinea pig against scurvy while over 12 cubic centimeters of the 

 first was required for protection. Both products retained their anti- 

 scorbutic properties after three months' storage. It was suggested at 

 this time that dried orange juice would be a convenient antiscorbutic 

 for use in infant feeding, on polar expeditions, and in navy and army 

 rations. 



Further studies of the juices of the orange, lemon and lime were 

 reported by Davey (1921). The minimum daily doses of the three 

 citrus fruits needed to protect the guinea pig from scurvy were es- 

 tablished as lemon and orange 1.5 cubic centimeters, and lime 5 cubic 

 centimeters. These values were used as a basis for comparing the anti- 

 scorbutic properties of the juice of oranges and lemons kept for vary- 

 ing times at different temperatures, alone, with the rind oil, and in the 

 case of lemon juice with the addition of sodium sulfite. Preservation 



