612 IOWA DEPARTMENT OF AGRICULTURE 



perature will fall slowly, but may be held more uniformly by covering 

 the bottles with a towel. The punctured cap should be replaced with 

 a new one, or the bottle should be covered with an inverted cup. 



After the milk has been held as directed it should be cooled as quickly 

 and as much as possible by setting in water. To avoid danger of break- 

 ing the bottle by too sudden change of temperature, this water should 

 be warm at first. Replace the warm water slowly with cold water. After 

 cooling, milk should in all cases be held at the lowest available tempera- 

 ture. 



This method may be employed to retard the souring of milk or cream 

 for ordinary uses. It should be remembered, however, that pasteuriza- 

 tion does not destroy all bacteria in milk, and after pasteurization it 

 should be kept cold and in a cleanly manner and used as soon as possible. 

 Cream does not rise as rapidly or separate as completely in pastuerized 

 milk as in raw milk. 



FOOD VALUE OF MILK. 



BY CAROLINE L. HUNT, EXPERT IN NUTRITION, OFFICE OF EXPERIMENT STATIONS. 



INTRODUCTION. 



It is a commonplace saying that milk, or to be more specific, cow's 

 milk, is a perfect food. This may be taken to mean that it contains, first, 

 materials which children need for growth second, materials which young 

 and old alike need for the repair of their bodily machinery; and, third, 

 materials which both need for fuel, i. e., to provide them with heat and 

 with the energy necessary for work. It should not be understood, how- 

 ever, to mean that it has these ingredients in such proportions that it 

 can serve satisfactorily as an exclusive food for a grown person or 

 even for a child. Though it is the best substitute for mother's milk, it 

 must be "modified" more or less before it can be used even for infant 

 feeding with good results. 



It is likewise a commonplace saying that milk is a cheap as well as a 

 nutritious food. Just at present with prices of all kinds of foods rapidly 

 changing it is not so easy as it once was to make the comparisons that 

 are necessary to show which particular foods are really cheap, but while 

 the prices of food materials vary the cmposition of most of them remains 

 unchanged, and it is always possible to compare their nutritive values. A 

 quart of milk supplies practically as much of both protein and energy 

 as three-quarters of a pound of beef of average composition or eight 

 average eggs, and can generally be bought for less money. In case milk 

 is 8 cents a quart, beef 20 cents a pound, and eggs 24 cents a dozen, 

 10 cents spent for milk will buy a little more protein and much more 

 enery than 10 cents spent for beef or 10 cents spent for eggs. Thus, 

 while other animal foods than milk (meat, eggs, and cheese) are desir- 

 able to give variety to the diet it may be assumed that milk may be used 

 as an economical substitute for any one of them. 



Of the vegetable foods, many (flour, for example) are found to be 

 much cheaper than milk when both price and nutritive value are taken 



