8 MASS. EXPERIMENT STATION BULLETIN 338 



Fomin and Makarova (65) found that B was lost in acid-preserved spinach, 

 but vitamin C was not. 



Effect of Heat on Vitamin B (B,) 



Newton (160) found that both raw and canned turnip greens contained 0.5 

 unit per gram. No vitamin B was lost by boiling the greens. However, 

 Munsell and Kifer (157) reported a 50 percent loss of B in cooking broccoli. 

 Scheunert and Wagner (185) found no loss on boiling for 30 minutes or in 

 pressure cooking for 10 minutes. The vegetables used were brussels sprouts, 

 cabbage, spinach, and potatoes. Scheunert (182) claimed that B was not 

 greatly injured by either boiling or canning. Still, Douglass and Richardson 

 (40) found that oven canning destroyed a part of the B of carrots. Pressure 

 cooker canning was without effect. Langley, Richardson, and Andes (117) 

 found a noticeable loss of B in cooking and a decided loss in canning carrots. 

 Van Veen (215) discovered that 50 percent of the B of unpolished rice was 

 retained after washing and steaming. Polished rice lost much B by washing 

 but none by steaming. Hoff (90) reported that cooking was more destructive 

 to B than canning. 



Daniels, Giddings, and Jordan (34) ascertained that both heat and oxidation 

 are harmful to the vitamin B of milk. On bubbling air through milk, or on 

 boiling, no loss in vitamin B was obtained by Spruyt and Donath (201). In 

 canning animal tissues, Elvehjem, Sherman, and Arnold (49) found that as 

 much as 80 percent of the vitamin B could be lost. In cooking oysters, 

 Whipple (222) observed no loss of B. 



The British Medical Research Council (137) states, "Continuous heating of 

 foodstuffs at 212° F., however, leads to some loss of vitamin B. In preserving 

 and canning foodstuffs the temperatures employed are frequently much higher 

 than 212° F., and canned foods of all descriptions may contain very [little or 

 no vitamin B (B x ) and, as a practical rule, should therefore be regarded as free 

 from it unless they have been especially investigated and found to contain it. " 

 Many of the earlier experiments on effect on vitamin B of environmental 

 factors are invalidated because of inability to differentiate the several factors 

 involved in the B complex. Kohman (106) has summed up a number of investi- 

 gations conducted previous to 1927 on the vitamin B complex. He states that 

 vitamin B is generally regarded as being less affected by oxidation than the other 

 vitamins. Commercially canned tomatoes, canned pineapple, peas and peaches 

 lose no appreciable amount of vitamin B (complex) in the canning process. 



Effect of Acidity 



Sherman and Burton (191) showed that by decreasing the acidity of tomato 

 juice from pH 4.28 to 5.2 the rate of destruction of vitamin B was increased. 

 This destruction was seemingly not influenced by oxidation and the loss was 

 presumably catalyzed by hydroxyl ions. On both sides of neutrality, the 

 rate of destruction was a function of the medium in which the vitamin B 

 was dissolved. 



