54 FOOD ADULTERATION AND METHODS FOB DETECTION. 



formerly, owing to the fact that packed eggs are usually preserved in 

 cold storage. There is now no means by which a fresh egg can be 

 distinguished from a packed egg without breaking it. Usually in eggs 

 that have been packed for a considerable time the white and } 7 olk 

 slightly intermingle along the point of contact, and it is a difficult 

 matter to separate them. Packed eggs also have a tendency to adhere 

 to the shell on one side and when opened frequently have a musty 

 odor. 



FLAVORING EXTRACTS. 



Although quite a large number of flavoring extracts are on the 

 market, vanilla and lemon extracts are used so much more commonly 

 than other flavors that a knowledge of their purity is of the greatest 

 importance. Only methods for the examination of those two products 

 will, therefore, be considered. 



VANILLA EXTRACT. 



Vanilla extract is made by extracting vanilla beans with alcohol. It 

 consists of an alcoholic solution of vanillin (the characteristic flavor- 

 ing matter of the vanilla bean) and several other products, chiefly 

 resins, which, though present in but small amount and having only a 

 slight flavor in themselves, yet affect very materially the flavor of the 

 product. Vanilla extract is sometimes adulterated with the extract of 

 the tonka bean. This extract to a certain extent resembles vanilla 

 extract. The extract of the tonka bean, however, is far inferior to 

 that of the vanilla bean. It has a relatively penetrating, almost pun- 

 gent odor, standing in sharp contrast to the flavor of the vanilla 

 extract. This odor is so different that one who has given the matter 

 some attention may readily distinguish the two, and the quality of the 

 vanilla extract may often be judged with a fair degree of accuracy by 

 means of the odor alone. 



Another form of adulteration and one that is now quite prevalent is 

 the use of artih'cial vanillin in place of the extract of either vanilla or 

 tonka beans. Artificial vanillin has, of course, the same composition 

 and characteristics as the natural vanillin of the vanilla bean. Extracts 

 made from it, however, are deficient in the resins and other products 

 which are just as essential to the true vanilla as is vanillin itself. 

 Since vanillin is thus obtained from another source so readily, methods 

 for the determination of the purity of vanilla extract must depend 

 upon the presence of other >ul>M;mrrs than vanillin. 



Detection of caramel. The coloring matter of vanilla extract is due 

 to substances naturally present in the vanilla bean and extracted there- 

 from by alcohol. Artificial extracts made by dissolving artificial 

 vanillin in alcohol contain no color of themselves, and to supply it 

 caramel is commonly employed. Caramel may be detected in arti- 



