14 MASS EXPERIMENT STATION BULLETIN 338 



was evacuated before freezing and the fruit stored in nitrogen; while the C of 

 fresh prunes was not injured by freezing, even when the air was not removed. 

 Both Shrader and Johnson (195) and Morgan, Langston, and Field (153) found 

 no difference in the C content of fresh and frozen orange juice. Blueberries and 

 strawberries showed no losses in C on freezing, (58, 60). In fact, strawberries 

 could be packed with sugar (frozen-pack) and later made into ice cream with no 

 measurable loss in C. 



In this laboratory, Fellers, Young, Isham, and Clague (64) found no loss in 

 freezing asparagus. Fellers and Stepat (62, 63) found that freezing either peas 

 or lima beans in itself caused little loss of C, but the manufacturing operations 

 incidental to shelling, washing, blanching, and freezing often removed 50 

 percent of this vitamin. However, once frozen, there was but little further 

 change at storage temperatures of -9.4° to -20.2° F. The defrosting of peas, 

 lima beans, and spinach unless quickly done was very destructive to vitamin C. 

 Losses of 70 to over 80 percent were found after defrosting these vegetables for 

 several hours. Obviously, the moral is not to defrost frozen fruits or vegetables 

 until they are ready to be cooked or served raw. By plunging the still-frozen 

 vegetables into boiling water, loss of C is reduced to a minimum. 



Effect of Germination and Fermentation on Vitamin C 



It is interesting to note that Ghosh and Guha (70) found an 8-fold increase in 

 the C content of mung beans during germination. Germination of potatoes 

 greatly increased the C at first, but this was followed by a marked decrease 

 according to Pett (165). Biswas and Ghosh (11) found the maximum C content 

 in mature peas after soaking 3 days in water. Germination increased the 

 vitamin C 21 to 47 times. 



Chang, Ma, Hoo, and Sah (19) examined over 50 Chinese vegetables for C. 

 They found the juices of the lotus and turnip rich in C and possible substitutes 

 for orange juice. It was demonstrated by Yarusova (227) that whereas fresh 

 cucumbers contained 0.08 to .16 unit of C per gram, the salt pickles made from 

 them contained none. Ivanova (97) showed that pumpkin lost one-half the C 

 on pickling. Krauss (115) claimed that apple and some other commercial fruit 

 juices contain little vitamin C. Oxidation destroys the C in stored and 

 fermented cider. Sauerkraut juice is of variable C content as shown by Clow, 

 Marlatt, Peterson, and Martin (22), Lavrov and Yarusova (119), and others. 

 In general, kraut juice and canned kraut are considered only fair sources of C by 

 Parsons and Horn (162), Von Hahn (76), and Clow, Parsons, and Stevenson (24) . 



Effect of Heat on Vitamin C 



A vast amount of research has been carried on relative to the effect of 

 cooking and canning on the C content of foods. Only the more recent studies 

 can be considered here. Attention is again called to the excellent summaries 

 by the British Medical Board (137), Kohman (106), Sherman and Smith 

 (193), the White House Conference Report (12), and others which bring 

 the subject up to about 1931. The use of the rapid titration technic with 2, 

 6-dichlorophenolindophenol dye (10) has greatly facilitated work in this field. 

 With the Sherman assay method it was difficult to determine under plant 



