ANALYSIS OF MILK PRODUCTS. 



13& 



TABLE XIII.— Ratio of Fat to Total Solids in Cream. 



This Tabic is not applicable to clotted cream. 



Skim Milk.^Tlie methods of milk analysis may be applied ; 

 the fat is rather more difficult of extraction. If Ritthaiisen's 

 method be used for protein determination, it is not necessary to 

 extract the fat, but to dry and weigh the copper precipitate, and 

 afterwards to subtract the percentage of fat found from the 

 percentage of proteins yAus fat. 



Condensed Milk. — About 30 to 35 grammes of tin- well- 

 mixed milk should be weighed into a 100 c.c. flask, diluted with 

 50 to 60 c.c. of water, and the solution raised to the boiling 

 point ; this is cooled, made up to 100 c.c. and the total weight 

 taken. The diluted solution is analysed as a milk. The fat is 

 rather more difficult to extract by Adams method than from 

 ordinary milk, and longer extraction should be given : the 

 Gottlieb method is the best ; if cane sugar is present, the Werner- 

 Schmid process must not be used for the estimation of the fat, 

 as cane sugar yields a substance soluble in ether. The Ritthausen 

 method must not be used. When soluble albumin is estimated, 

 a fresh portion which has not been boiled is employed. 



Sour, Fermented, or Decomposed Milk — Preparatioi of 

 Sample. — The whole contents of the bottle are turned out into 

 a beaker and whisked for a minute or two w"ith a brush made of 

 fine wire : the inside of the bottle is scraped all over with a wire, 

 some of the milk is poured back, and the contents shaken ; this 

 is now emptied into the beaker and again whisked. 



Many samples on mixing yield a portion of their fat in a churned 



