Fractionation of the Stale-Flavor Components of Dried Whole Milk

Abstract

The stale flavor of dried whole milk exists in 2 forms separable by CC14-vapor distillation and Girard''s-T extraction. A nonvolatile one is extracted from milk fat with Girard''s-T reagent; a volatile one is not recovered from the Girard''s-T extract after hydrolysis of the resulting hydrazones. The Girard''s-T extract can be separated by chromatography into a stationary and a mobile component which contains the flavor. The mobile component which resembles an aldehyde is readily decomposed by alkali or 2,4-dinitrophenylhydrazine in 4 M RCl. The CC14-vapor distillate contains at least 7 carbonyl compounds: formaldehyde, acetaldehyde, propionaldehyde, acetone, 2-pentanone and 2 unidentified compounds; one a saturated monocarbonyl compound and the other an unsaturated dicarbonyl or hydroxycarbonyl compound. The stale-flavor component of this fraction reacts as a dicarbonyl compound with Girard''s-T reagent.