ADULTERATIONS OF MILK 



ALTHOUGH adulterations and preservatives are no longer com- 

 monly used, they are still a source of temptation to some. Fraud- 

 ulent intent and the pressure of legislation sometimes induce 

 producers to take refuge in adulterating their product and in 

 using preservatives so as to prolong the salable character of the 

 milk. The addition of chalk, calves' brains, starch, glycerin, and 

 similar substances, for the purpose of restoring solids and vis- 

 cosity when the milk has been tampered with, need no considera- 

 tion. Their application has never been common and is largely 

 mythical, but skimming of milk is probably still practised and 

 the addition of water or skimmed milk not uncommon. Tests 

 for such adulterations are, therefore, imperative. However, 

 there is some difficulty experienced in determining fair and re- 

 liable standards which give a clear definition of what normal milk 

 ought to be. The fat content, as has been shown, is variable ac- 

 cording to the breed of cows from which the milk is obtained 

 and according to a number of other conditions which have been 

 discussed in detail in a former chapter. Furthermore, the milk 

 of some breeds naturally contains less fat than 3 per cent., which is 

 the lowest legal limit usually permitted in this country. On the 

 other hand, the milk of some breeds contains more fat than legally 

 required, and there is the temptation to remove some of the cream 

 from such rich milk, as long as the remaining product averages well 

 within legal limits. 



After the milk has been skimmed or watered, thickening agents 

 and coloring-matter are sometimes added in an attempt to re- 

 store at least the appearance and consistency of the milk. How- 

 ever, the composition is permanently altered by this addition. 



The adulterations of milk which have been detected may be 

 treated under the following heads: 



1. Reduction of fat by 



(a) Addition of water. 



(6) Skimming of milk. 



(c) Both watering and skimming. 



2. Addition of thickening agents to restore consistency, vis- 

 cosity, and solids. 



3. Addition of coloring-matter to restore color lost by skim- 

 ming or diluting, or to make naturally poor milk appear rich. 



4. Addition of preservatives. 



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