336 



CITY MILK SUPPLY 



ate them for if it is not done correctly the homogenized milk will have a 

 "burnt" or "metallic" flavor readily detectable by those who are familiar 

 with it. 



Baldwin made two sets of measurements of the fat globules in samples 

 of homogenized cream from two different machines working under pres- 

 sures of from 700 to 4,000 Ib. per square inch. He found that in general 

 the degree of homogenization is increased with the pressure and in one 

 of the machines the destruction of fat globules is so great that most of 

 them lose their spherical form and under a 2-mm. objective look like a 

 fine amorphous precipitate. The diameter of the majority of fat globules 

 Baldwin found to be of 0.005 to 0.006 mm. and of the homogenized 

 globules 0.001 to 0.002 mm. The experiments are given in Table 99. 



TABLE 99. RELATIVE NUMBER OF FAT GLOBULES OF VARIOUS SIZES IN NATURAL 



CREAM AND IN CREAM HOMOGENIZED UNDER VARIOUS PRESSURES (BALDWIN) 



Diameters in millimeters 



Homogenized milk is used to some extent for infant feeding and for 

 invalids, and mixtures are used, too, that are made by homogenizing olive 

 oil or other fats in place of the butterfat. Some milk dealers put out an 

 homogenized milk or cream that is popular with their customers and 

 takes the place of coffee cream. A drawback to this product is that it 

 sometimes curdles when coffee is poured onto it. If ice-cream manufact- 

 urers did not purchase and store large quantities of butter fat when milk 

 is plenty they would not have it for making ice cream at seasons when 

 little is to be had. They have two ways of meeting the situation : one of 

 them is to freeze large quantities of sweet cream and hold it in cold storage 



