VITAMIN C 189 



tomatoes do not ordinarily contain as much vitamin C as field-ripened 

 tomatoes on account of the fact that they are not as ripe when used, 

 but if allowed to ripen thoroughly give comparable results. Green 

 tomatoes ripened at 70° F. after picking were reported to contain as 

 much vitamin C as the vine-ripened fruit. House, Nelson and Haber 

 (1929) on the other hand found vine-ripened tomatoes to be richer 

 in vitamin C than air-ripened or ethylene-ripened, although this was 

 not the case with vitamin A or B. No differences could be detected in 

 their experiments between the vitamin C content of air-ripened or 

 ethylene-ripened fruit. 



Jones and Nelson (1930), using in their tests only that portion of 

 the tomato which passed through a fine muslin cloth, concluded that 

 naturally ripened tomatoes contained the most vitamin C, followed by 

 full grown green tomatoes and then by the small immature fruit. 

 Ethylene treatment of the green fruit produced no change in the vita- 

 min C content. No tests were reported for air-ripened fruit. 



Berries are much sought as antiscorbutics in northern regions but 

 appear to have been little studied. Hoist and Frolich (1912) reported 

 raspberries and cloudberries to be good antiscorbutics and state that 

 their juices can be boiled, canned and kept for months with relatively 

 little loss of antiscorbutic potency. 



Kohman, Eddy and Halliday (1928) found strawberries to be as 

 rich as tomatoes in vitamin C and to show no appreciable loss in this 

 vitamin when canned by the usual commercial methods. In their experi- 

 ments, from two to three grams daily of the fresh berries, or the 

 equivalent in canned, provided sufficient vitamin C for protection of 

 guinea pigs against scurvy. Scheunert (1929) considered strawberries 

 to be a good source of vitamin C. In his experiment, protection was 

 secured with five grams daily. No appreciable differences were noted 

 between different varieties, and canning or preserving brought about 

 only a slight decrease in the vitamin C content. Raspberries, red and 

 white currants, and gooseberries were also reported by Scheunert to 

 be good sources of vitamin C and in general to retain their antiscorbutic 

 properties when canned or preserved. Commercial fruit juices (manu- 

 factured according to the German Pharmacopoeia) were very low in 

 vitamin C. 



Other fruits tested by Scheunert included apples which he con- 

 sidered a fairly good source of vitamin C on account of their being 

 eaten so extensively raw ; pears, apricots, peaches and plums all of 

 which were low in vitamin C, and cherries, a good source of vitamin 

 C when raw but poor when cooked or canned. 



