28 BULLETIN 661, U. S. DEPARTMENT OF AGRICULTURE. 



Table 5. — Comparison <>l calculated and actual fat content of casein. 





Fat 

 contonl <>i 

 butter- 

 milk. 



Fat content of casein. 



Sample No. 



Calculated. 



By ether 

 extraction. 



56.3 



Per cent. 

 .07 

 .IS 

 .20 

 .16 

 .28 

 .89 

 .015 

 .35 

 .60 

 .07 

 .01 

 .13 

 .04 

 .02 

 .19 



Per cent. 



2.31 



5.94 



6.60 



5.28 



9.24 



29.37 



.495 



11.55 



19.80 



2.31 



.33 



4.29 



1.32 



.66 



6.27 



Per cent. 



56.4 



9.89 



56.9B 



23. 83 



56. 10A 



5ii.UA 



56. 13A 



56.14 



6.31 



8.71 



21.27 



.93 



56.1614 



12.63 

 14. 10 



56.17B 



9. 67 



56.20A 



56.23A : 



56.25A 



56.30A : 



4.29 

 9.52 

 3.98 

 7.53 



4. IS 



All analyses oi casein samples were made by R. H. Shaw and E. F. Deysher, of the Dairy Division. 



Analyses of samples of domestic and foreign skim-milk casein and 

 of buttermilk casein appear in Table G and show the difference in 

 chemical composition. The buttermilk samples, made from what 

 would be regarded as the usual run of buttermilk in creameries re- 

 ceiving a good grade of cream, show a marked increase in fat, as 

 was to be expected. 



Table 6. — Comparative analyses of shim-milk and buttermilk casein. 





Origin. 



Chemical analysis. 



Sample No. 



Mois- 

 ture. 



Fat. 



Ash. 







Per cent. 

 7.80 

 8.28 

 7.95 

 6.44 

 8. 43 

 7.74 

 7.65 

 6.68 

 6.82 

 5.86 

 6.42 



Per cent. 

 0.60 

 0.93 

 0.66 

 1.04 

 0.75 

 0.93 

 6.54 

 5.00 

 9.52 

 5.62 

 5.82 



Per cent. 

 2.80 



56.41 



do 



2.44 







1.89 



56.44... 





3.69 



56.45... 





1.86 



56.14 





1.14 



56.10B 





0.99 







1.30 



56.23A 



....do 



0.60 



56.35C... 



.do... 



0.76 



56.37 



....do... 



1. 19 









METHODS OF DETERMINING QUALITY OF CASEIN. 



In order lo determine factors having a direct bearing upon the 

 quality of buttermilk casein and the conditions requisite to the man- 

 ufacture of a product of the best practical value, a study of the 

 solubility, adhesiveness, and general working properties of various 

 lots of casein made under varying conditions was undertaken. But- 

 termilk from pasteurized sweet cream ripened to an acidity of from 

 0.40 to 0.05 per cent was used in the investigational work, and no 



