Milk Lipase System. III. Further Studies of the Solvent Extraction Procedure for Obtaining Fat from Milk for Titration

Abstract

Results are presented of 2 attempts to modify the solvent procedure developed for the purpose of isolating milk fat for acidity measurements (described in Part II of this series). The 2 modifications studied were the saturation of the milk or cream with salts (MgSO4 and NaCl) before extraction, and the acidification of the milk to pH2 with H2SO4 before extraction. Only the acid adjustment was found to yield sufficient improvement of recovery of fatty acids to warrent its adoption as a part of the solvent extraction procedure. Acid degrees of fat from normal and rancid milks were 1.38 and 19.79 for the acid-treated samples as compared to 1.07 and 18.82, respectively, for the untreated samples. A comparison of the solvent extraction method with a procedure involving continuous extraction of milk previously dried in plaster of Paris revealed the latter to be inefficient in its recovery of fatty acids from milk.