14 



THE STORY OF MILK 



SOUJJS W9T FAT 

 TOTAL SOLIDS 



Composition of 

 cow's milk 



MINERAL MATTER 

 MILK SUGAR 



animal and vege- 

 table fats, but the 

 CASEIN 8. ALBUMIN- sHght Variation 

 BUTTER FAT may make a lot 

 of difference in digestibility 

 and palatability as well as in 

 nutritive value, ' and it is a mistake to consider 



Oleomargarine, Butterine, Nut-Butter and 



other substi- tutes for butter ''just as good" 



because a I chemical analysis shows them 



to contain ''al- most" the same elements 



or compounds. These products may be good 



and legitimate if sold for what they are, but 



should never 0^ be allowed to be sold or served 

 for what they [^ are not, genuine butter. 



Casein and ^ Albumin are the proteids or 

 nitrogenous ^ matters of the milk, in chemical 

 composition ^ and in food value much the 

 same as the protein in beans and peas or 



in meat, or the white of eggs. Casein is present 



in much larger quantity than albumin and is 



distinguished from the latter by being pre- 



cipitated b y rennet, which has no effect on 



albumin. Ca- sein may also be precipitated by 



acids, while it requires boiling as well as acid- 



ity to throw the albumin out of solution. 



Milk-Sugar is related to the vegetable sugars, 



glucose, cane sugar, etc., and remains in solu- 



tion in the whey which separates out from 



the cheese-curd | | when milk is curdled with ren- 

 net or acids. The whey also contains the mineral 

 matters or ash, which consists largely of phosphate 

 of lime, of use to the young in building up bones. 



