CONTAMINATION OF FOODS 153 



come in contact will) them. There are two important ex- 

 amples that are quite comparable to milk in every respect. 

 Oysters can not be subjected to any preservative agent 

 other than cold. They are constantly exposed to contami- 

 nation, and form an ideal medium for many bacteria. The 

 water in which the oyster is grown supplies the initial con- 

 tamination. They are commonly immersed in fresh water 

 for a short period for the purpose of ''plumping." The 

 streams in which they are placed are often contaminated 

 with sewage. A contamination with both saprophytic and 

 pathogenic bacteria is thus possible. In opening the shells, 

 the oyster is exposed to contamination from the hands of 

 the worker, and the utensils also serve to add their quota 

 of bacteria. The juice of the oyster is rich in protein and 

 neutral in reaction, supplying an ideal environment for the 

 TO\\- ih of putrefactive bacteria. 



Chopped meats present similar problems. In their prep- 

 aration the bacteria are uniformly mixed with them. Food 

 and moisture are abundant. Spoilage quickly occurs un- 

 less the bacteria are restrained in their development. 



Contamination of foods is not confined to the handling 

 t hey receive in the channels of commerce, but occurs in the 

 home. Unused portions of food left over from the day's 

 meal are peculiarly liable to bacterial activity. The con- 

 tamination in the home is largely from utensils, the ade- 

 quate sterilization and drying of which will do much to 

 enhance the keeping of food from one day to another. 



It is essential that all foods that must be used without 

 previous cleaning, and especially those that are eaten with- 

 out cooking, be protected from contamination, both for 

 esthetic and sanitary reasons. Bakery goods, candies, etc., 

 should be handled with due regard to cleanliness. Dust 

 contamination and pollution incident to handling food 

 products are especially to be considered. 



