INFLUENCE OF FOOD PRESERVATIVES AND ARTI- 

 FICIAL COLORS ON DIGESTION AND HEALTH. 



III. SULPHUROUS ACID AND SULPHITES. 



INTRODUCTION. 



The relations of sulphurous acid to health are perhaps of greater 

 importance than those of the preservatives already studied namely, 

 boron compounds and salicylic acid and its salts. The reason of this 

 is found in the fact that the use of sulphurous acid at the present time 

 is more general, and in certain classes of food products, according to 

 the statements of manufacturers, more nearly approaches a necessity 

 than is the case with boron or salicylic acid compounds. 



Sulphurous acid in some form is extensively employed in many 

 technical operations in the preparation of foods. This is especially 

 true in the production of wine, in the preparation of evaporated or 

 desiccated fruits, and in the manufacture of molasses. The problem 

 presents itself under two aspects namely, the use of sulphurous acid 

 or its compounds for technical purposes in the preparation of foods 

 and its application to the finished products as a preservative. 



In the preparation of foods, sulphurous acid is chiefly employed in 

 the form of the fumes of burning sulphur, applied either to the food 

 products themselves in the course of manufacture or to the con- 

 tainers in which the food products are held. In the ripening of the 

 wines in cellars it is customary to fumigate the barrels with burning 

 sulphur each time the wines are racked. In this manner it often 

 happens that the wine before it is finally ready for sale on the market 

 may have been placed in five or more freshly sulphured containers. 

 By this treatment the wine absorbs a varying quantity of the sul- 

 phurous acid, depending to some extent upon the amount of sulphur 

 used in fumigating. 



When sulphurous acid is used as a preservative for food products 

 after the manufacture has been completed it is usually employed in 

 the form of bisulphite of lime or some similar preparation. Sulphur- 

 ous acid has the property of uniting with certain organic radicals, 

 such as aldehydes and some sugars, to form compounds which are 



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