16 MASS. EXPERIMENT STATION BULLETIN 338 



on the C content of oranges, grapefruit, or their juices. Fermented or candied 

 citron lost all the C but retained the A in experiments reported by Fellers and 

 Smith (61). Blueberries (58, 138) gave variable results as to C retention; some 

 experimental packs showed good retention while others showed poor retention. 

 Retention of C could not be correlated with blanching, kettle cooking, or 

 vacuumization. 



Clow and Marlatt (23) found that tomatoes canned by the open-kettle 

 method were slightly inferior to those canned by other methods. They also 

 showed that green tomato pickles retain but little C. Daggs and Eaton (30), 

 and Spohn (200) reported that canned tomatoes and juice were inferior to 

 fresh in C content. Results in this laboratory (54) show that while commer- 

 cially canned tomato juices are variable in vitaminC content, in general they are 

 good antiscorbutics. Some juices had 6 units per gram while others had only 1 

 to 2 units per gram. In general, home canned tomato juice was as satisfactory 

 as commerically canned. No significant differences in C content could be 

 observed between homogenized and non-homogenized tomato juices. Kohman, 

 Eddy, and Zall (111), and Kohman, Eddy, and Gurin (110) found some loss 

 in C in the concentration of tomato juice to puree; but the loss was not pro- 

 portional to the concentration, the tomato concentrate being weight for 

 weight richer in vitamin C than the original tomato. Mathieson (135) found 

 that concentrated tomato pastes with 20 percent total solids contained no 

 more C than paste with 40 percent. Similarly, Aschehoug (1) determined the 

 minimum protective levels for guinea pigs at 8 and 10 grams respectively, for 

 tomato pastes containing 18 and 25 percent total solids. Daniel, Kennedy, and 

 Munsell (31) found definite losses in vitamin C of both tomato and orange juices 

 when prepared 6 hours before use. This loss increased with storage time. 

 Also, Daniel and Rutherford (33) showed that both the canning process and the 

 storage of canned tomatoes and tomato juice had significant destructive 

 effects on vitamin C. The losses varied from 21 to 55 percent. Both factors 

 caused about equal losses of C in canned tomatoes and juice. Losses of vitamin 

 C were greater when storage was carried on in glass containers. Tomato 

 conserve was found to retain only 14 to 15 percent of the original vitamin C 

 of the tomatoes by Soloveichik (199). Giroud, Ratsimamanga, Macheboeuf, 

 Cheftel, and Thuillot (71) showed good retention of vitamin C in canned 

 acid vegetables. According to Hess and Unger (86, 87), and Sherman, La Mer, 

 and Campbell (192), the neutralization of tomato juice destroyed much of its 

 C. Kenny (103) proved that the loss in vitamin C during the heating of 

 tomato juice was correlated with the oxidation potential. Kohman (107) and 

 Kohman, Eddy, and Gurin (110) applied the principle of deaeration and ana- 

 erobic handling to the manufacture of tomato juice with good results. Barnby 

 and Eddy (5) found no differences in C content in tomato juice packed in tin or 

 in glass containers. They also found viscolization of the juice to be without effect 

 on its vitamin C activity. 



Rigobello (175) pointed out that lemon jelly retained approximately 50 per- 

 cent of the C value of the lemon. Bacharach, Cook, and Smith (4) showed that 

 citrus marmalade retained only 10 to 30 percent of the C in the fruit. Fellers 

 Isham, and Smith (59) and also Todhunter (210) found that apple sauce lost 

 over 50 percent of the C of the fresh fruit. They found apple pie to be only 



