CONTAMINATIONS OF CANNED VEGETABLES. 1025 



tered work has been done on canned foods, though nothing systematic, 

 and rich as is the literature relating to food adulterations, singularly 

 little of it has to do with the examination of these goods. 



In this country little attention has been paid to the ma.tter. Massa- 

 chusetts, working under an efficient food and drug law, has done some 

 work toward preventing the sale of sophisticated imported canned 

 foods, but as far as the records show has done little or nothing with 

 American goods. 



The Brooklyn board of health for some years has been devoting 

 more or less attention to canned foods, and in particular to those 

 which are coppered. 



Canned vegetables are not much subject to adulteration in the 

 restricted sense of the word, which implies the addition of foreign sub- 

 stances to food for the purpose of increasing its quantity. The only 

 practice in vogue which can properly come under this head is the 

 addition of undue amounts of water during the canning process. This 

 often occurs. Additions of salt might be regarded in this way, but 

 this substance is added primarily as a condiment. Of adulteration in 

 the more modern sense, that which includes sophistication, there is a 

 great deal, and indeed it may be said to be almost universal. There 

 are few canners who do not use salicylic acid or other preservatives, 

 and the trade in coppered vegetables has grown to enormous propor- 

 tions. Besides these wilful additions there is a class of what may be 

 called unintentional sophistications, such as the presence of lead, tin, 

 or zinc in these foods. These substances are often present, but are 

 never, except occasionally in the case of zinc, added intentionally. 



Ptomaines are often said to be present in canned foods, and this may 

 sometimes be the case, but their occurrence in canned vegetables must 

 be extremely rare. Ptomaines are by definition the result of bacterial 

 action, and where this action does not occur they must of necessity be 

 absent. Vegetables are usually canned in the fresh state, and if they 

 are in any degree spoiled at the time, the fact is usually conspicuously 

 evident to the taste, so that the canner can not afford to use them. 

 Bacterial action seldom occurs in the can without bursting it or render- 

 ing it unsalable. Ptomaines may, however, develop where the canned 

 food is allowed to stand for some time after opening, though even then 

 this is unlikely in the case of preserved vegetables. 



It may be said, therefore, that the principal risks to health which may 

 arise from the use of canned goods are those due to the use of pre- 

 servatives, or to the presence of the heavy metals, copper, tin, lead, 

 and zinc. Iron, though often taken up by the food in considerable 

 quantities from badly tinned cans, may be disregarded in this case, 

 since it is not only a normal constituent of food, though hardly in the 

 forms which it assumes in canned goods, but is not poisonous. Its 

 desirability as an addition to food may be questionable, but it can not 

 be called materially deleterious. In regard to the other substances 

 mentioned, the case is different. 

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