10 MASS. EXPERIMENT STATION BULLETIN 338 



which the heating takes place." For example, Guha and Chakravorty (75) 

 found that the optimum reaction for extraction of G was at pH 5.0, while 

 heating ox kidney for 15 minutes at pH 10.5 in water destroyed most of it. 

 Halliday, Nunn, and Fisher (78), also Chick and Copping (20), observed that 

 the inactivation of G increases rapidly with increasing alkalinity. 



There has been no reported work on the effect of freezing on vitamin G, 

 but it seems improbable that there would be any loss. 



In summarizing the work on vitamin G, it is found that, although fruits and 

 vegetables in general are rather poor sources of G, still it is very widely dis- 

 tributed. Furthermore, the preponderance of the existing data indicate that 

 G is not seriously injured by the usual methods of food preservation such as 

 drying, fermentation, freezing, and canning. Only in alkaline media or in 

 long heat exposure in air is the G destroyed. It is, of course, water soluble and 

 unless the juices of cooked fruits and vegetables are utilized, losses will occur. 



VITAMIN G 



Vitamin C, the anti-scurvy vitamin, is of particular interest in this review 

 because fruits and vegetables are the principal sources of it. More researches 

 have been reported on the effect of environmental factors on vitamin C than 

 on all the other vitamins combined. The writer, without claiming any degree 

 of completeness in his literature search, collected 235 references — nearly all 

 published since 1928. A literal avalanche of investigations is now being carried 

 on since the discovery by Tillmans (209) of the rapid titration technic for the 

 determination of vitamin C. 



Vitamin C is important for another reason; namely, that since the body 

 does not store the vitamin at all, it is necessary to continually replenish the 

 supply. This makes it very desirable to know which foods carry C and which 

 do not. It is likewise important to know whether the various methods of 

 food preservation such as drying, freezing, canning, and cold storage adversely 

 affect the C content of fruits and vegetables. 



Because of the impossibility of covering the entire literature in this brief 

 survey, the reader is referred to the summary compiled in 1927 by Kohman 

 (106), to that of Sherman and Smith (193) in 1931, and to the Report of the 

 British Medical Research Council (137) in 1932. A number of less complete 

 surveys have also been published by Bacharach (2, 3), Smith (196), Scheunert 

 (183), Priestly (168), Dutcher (43), Fellers (53) and Cowell (27). 



Effect of Maturity and Storage on Vitamin C 



Apples lost most of their C in 6 to 9 months according to Pelc and Podzimkova 

 (164). Storage was also harmful to the C in oranges. Bracewell and Zilva (16) 

 found no loss in C in 2 months in oranges and grapefruit. Todhunter (210,211 ) 

 and also Batchelder (7) found that the losses in Delicious and some other 

 apple varieties were approximately 17 percent in 3 months at 45° F., 25 percent 

 in 6 months, and 50 percent in one year. Fellers, Cleveland, and Clague (55) 

 determined that the loss of C in Baldwin apples stored at 36° F. for 4 to 6 

 months was 20 percent, and after 8 to 10 months, 40 percent. Van Leersum 



