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

Summary 1.Results are presented of two attempts to modify the solvent extraction procedure for the obtaining of fat in lipase studies so as to increase the efficiency of recovery of the lower fatty acids. The two modifications studied were: (a) the saturation of the milk with salts (MgSO 4 and NaCl) before extraction and (b) the acidification of the milk to pH 2 with H 2 SO 4 before extraction. 2.Of these modifications, only the acid adjustment of the milk or cream was found to yield sufficient improvement in recovery as to warrant its adoption as a part of the solvent extraction procedure. 3.A comparison of the solvent extraction method and a procedure involving continuous extraction of milk previously dried in plaster of Paris reveals that the latter method does not remove efficiently the free fatty acids from milk.