160 PROTECTION OF THE CONSUMER. 



stated that children brought up on such milk learn to enjoy 

 its taste and will not drink raw milk. The public taste is cer- 

 tainly subject to education and with little doubt could be edu- 

 cated to the use of cooked milk. But the fact remains that, in 

 America at all events, the public in general do not enjoy 

 cooked milk and will not drink it, while raw milk is a widely 

 used food. Most people prefer not to drink milk at all rather 

 than to drink boiled milk, being willing to use the latter in 

 cases of sickness, but not as a beverage in time of health. 

 Hence the adoption of sterilization of milk would greatly 

 reduce the amount consumed, a result to be greatly depre- 

 cated from the standpoint of both the dairy interest and 

 public health, inasmuch as milk is one of the cheapest and 

 best of foods. 



4. The high heat produces chemical changes in the milk 

 of considerable importance. It modifies the condition of the 

 fat emulsion. It produces a partial caramelization of the 

 milk sugar, frequently resulting in a slightly brownish color. 

 It modifies the nature of the casein so that the rennet ferment 

 of the stomach, although it will curdle it, produces a curd of 

 a different physical nature from the curd of raw milk. Heat 

 coagulates the albuminoid present in the milk, the scum 

 which appears on the surface of the milk being in part such 

 coagulated albumen. Heat destroys some of the phosphoric 

 proteids. The heat also destroys the ferments or enzymes 

 which are in the milk, the galactase, for example, being ren- 

 dered quite inert by the action of sterilization. Some of the 

 soluble calcium salts are converted into insoluble calcium phos- 

 phate. These changes render sterilized milk quite a different 

 material from natural milk. While they do not interfere 

 with the chemical value of the milk as food they do some- 

 what interfere with the ease of its digestion and assimilation. 

 From the first use of sterilized milk the question of its digesti- 

 bility has been disputed. Numerous experiments have been 

 carried out to compare the relative digestibility of sterilized 



