OCCURRENCE IN FOODSTUFFS 



onion, 0*005 to 0-015 ; pea (freeh), o-oi to 0-28 ; potato, 0*0075 to 

 0-2 ; radish, 0-02 ; spinach, 0-057 to 0-089 i tomato, 0-05 to 0-236 ; 

 and turnip, 0-04 mg. per 100 g. 



The effect of storage and cooking on the riboflavine content of 

 vegetables was studied with spinach and asparagus.^ The amounts 

 present in the fresh materials were 0-21 and 0-32 mg. per 100 g. respec- 

 tively. On storage for twenty-four hours at i8-8 to 25-5° C, the loss 

 of potency was only 5 and 22 % respectively and, on storage for one 

 week at o to 4-4°'C., only 17 and 27 %. The losses on freezing, how- 

 ever, were 40 and 42 % respectively. From 52 to 91 % of the ribo- 

 flavine was retained on cooking. Cabbage lost little of its riboflavine 

 content on dehydration with or without sulphiting, and the loss on 

 cooking was 20 to 40 % ; a similar loss occurred on cooking potatoes.^ 



Cow's milk contained 0-027 to 0-3 mg. per 100 ml., most recorded 

 values being between o-i and 0-15 ; colostrum contained 0-6 mg. per 

 100 ml.^o A decrease in the riboflavine content of milk from 0-18 to 

 0-13 mg. per 100 ml. occurred when cows were transferred from pasture 

 to artificial feeds. ^^ Pasteurising at 143 to 145° F. for thirty minutes 

 scarcely affected the riboflavine content of milk.^^ Dried whole milk 

 contained somewhat larger amounts of riboflavine when prepared by 

 spray drying (1-54 mg. per 100 g.) than when prepared by roller- 

 drying (1-48 mg. per 100 g.).^^ A similar relationship existed between 

 the two types of dried skim milk, which contained 1-98 and 1-88 mg. 

 per 100 g. respectively. 



Ewe's colostrum and milk contained 2-0 and 0-44 mg. per 100 ml. 

 respectively.^^ 



Butter contained 0-008 and cheese 0-12 to 0-8 mg. per 100 g.^* 

 The older values recorded for eggs were : yolk, 0-5 to o-6 and white, 

 0-4 to 0*5 mg. per 100 g., whereas lower values were obtained more 

 recently ,^^ namely : yolk, 0-24 to 0-4 and white, 0-19 to 0-29 mg. per 

 100 g. 



Fish muscle contained relatively large amounts of riboflavine, 

 ranging from 0-046 to 0-31 for cod ; o-i to 0-4 for herring ; and aver- 

 aging 0-2 for flounder ; 0-165 for haddock ; 0-185 tor halibut ; and 

 0-66 mg. per 100 g. for mackerel. Hard roe was much richer in ribo- 

 flavine than was muscle from the same species of fish, with one excep- 

 tion, the following values being recorded : cod, 0-7 to 1-13 ; flounder, 

 0-48 to 0*57 ; haddock, 1-42 ; and mackerel, 1-14 mg. per 100 g. 

 Herring roe, however, contained only 0-385 mg. per 100 g. Soft roe 

 was generally a poorer source of riboflavine than hard roe. 



Some crustaceans were found to contain relatively enormous 

 amounts of riboflavine, and some of the tissues from certain crabs 

 are among the richest known sources. ^^ The antennary glands of 

 certain melanin-containing crabs, for example, contained 1-4 to 27-5 



165 



