250 



THE ANALYSIS OF BUTTER FAT. 



The presence of coconut oil may be inferred if the Polenske 

 figure is more than 1-0 c.c. higher than those given in the table 

 below. 



Kirschner figure. 

 26, 

 24, 

 22, 

 20, 



Polenske figure. 



. 3-2 



. 2-6 



. 2-1 



1-6 



Cranfield confirms these figures, his values being 

 Kirschner figure. 



24 to 24-4, 

 23 24, . 

 22 23, . 

 21 22, . 

 20 21, . 

 19 20, . 



Av. 

 2-65 

 2-4 

 2-43 

 2-05 

 1-65 

 1-46 



Polenske figure. 



Limits. 

 2-6 to 2-7 

 2-2 2-6 

 1-8 2-9 

 1-7 2-7 

 1-4 2-2 

 1-4 1-7 



Both sets of figures agree in giving the approximate relation 

 in butter. P == (K 14) X 0-26, and in the case of Cranfield's 

 individual results the difference never exceeded 0-7 c.c. 



It may be safely assumed that if the Polenske figure is higher 

 than (K 10) X 0-26 the presence of coconut or palm-kernel oil 

 is established. 



The Kirschner method is of especial value in estimating the 

 quantity of butter in mixtures containing small amounts when 

 large quantities of other fats are present e.g., in margarine, 

 which under the Margarine Act is not permitted to contain more 

 than 10 per cent, of butter. 



The percentage of butter may be calculated from the formula 



_, K- (0-262 P' 63 + 0-09) 

 0-242 



where B = percentage of butter fat, 

 K = Kirschner figure, 

 P = Polenske figure. 



The following table will give the values of (0-262 P 0<63 -f 

 0-09) : 



P. 

 0-5, 

 I, 



2, 

 3, 



4, 

 5, 

 6, 



7 



Value. 

 0-26 

 0-35 

 0-50 

 0-61 

 0-72 

 0-81 

 0-90 

 0-98 



P. 



8, 

 9, 

 10, 

 11, 

 12, 

 13, 

 14, 

 15, 



Value. 

 1-06 

 1-13 

 1-21 

 1-28 

 1-34 

 1-41 

 1-47 

 1-53 



