VITAMIN C 191 



to be related to the soil in which it was produced, the age of the tree, 

 or the season. Apples picked before complete maturity were as active 

 as those picked from the same tree 14 days later. Next in order of 

 vitamin C value was the Dabinett, a cider variety, while Cox's Orange 

 Pippin, a dessert variety, ranked last. Canadian dessert apples had about 

 the same vitamin C value as the corresponding English varieties, but 

 Australian and New Zealand apples were less potent, probably on ac- 

 count of increased time elapsing between the picking and testing of 

 the fruit. Little loss in vitamin C value was demonstrated in the English 

 grown apples during three months' storage in air at 1° C. Storage in a 

 mixture of carbon dioxide, nitrogen, and oxygen at 10° C. for the 

 same period resulted in a slightly greater loss in activity. Apples of 

 the Bramley variety were baked for 50 minutes in their skins without 

 noticeable loss in antiscorbutic properties. The remarkably high content 

 of vitamin C in this one variety of apple was not accompanied by any 

 detectable differences in such factors of chemical composition as are 

 shown by analysis in vitro, with the possible exception of the nitrogen 

 content which appeared to be higher in the variety of high vitamin C 

 content. i , | 



Kohman, Eddy, Carlsson and Halliday ( 1926) found that 5 grams 

 of raw peaches purchased in the New York market during August, 

 September and October was about the minimum protective dose. The 

 same peaches cooked by the open kettle method contained only about 

 one-fifth as much vitamin C as the fresh peaches, but peaches canned 

 in California by commercial methods appeared as rich as the fresh New 

 York City market peaches. Unlike apples the elimination of the oxygen 

 from the peaches previous to processing was without appreciable effect 

 on the vitamin C content of the canned product. 



In a recent study by Morgan and Field (1929) of the effect of 

 various methods of drying upon the antiscorbutic properties of fruits, 

 the minimum protective dose of fresh Muir peaches was given as eight 

 grams daily. Unsulfured sun-dried or dehydrated peaches retained no 

 detectable amount of vitamin C, but the sulfured fruit dried by either 

 method showed no measurable loss in vitamin C. In commenting upon 

 the protective action of sulfur dioxide upon vitamin C as thus demon- 

 strated the authors state : 



"The mechanism of protection of vitamin C by the sulfur dioxide treatment 

 in these fruits is of interest and is being studied in this laboratory. Whether the 

 result is due to decreased oxidation because of a surface coagulation of the fruits, 

 or because of the reducing action of the sulfur dioxide, or to greater stability of 

 the vitamin in the possibly more acid medium provided by the sulfurous acid, or 

 to some other cause remains to be discovered. In any case, a definite advantage 



