The Coconut-Like Flavor Defect of Milk Fat. II. Demonstration of δ-Decalactone in Dried Cream, Dry Whole Milk, and Evaporated Milk

By the use of chromatograms the presence of ~-decalactone in dried cream, dried whole milk, and evaporated milk was determined.This study emphasizes the need for further research on the factors leading to the formation of various unreported trace elements that may be present in or associated with the lipid fraction of milk and its products.Editor.The coconut-like off-flavor is a major storage defect of a number of fat-containing dairy products.The preceding paper dealt with isolation of 8-decalactone, the off-flavor compound, from butter oil; and two paper chromatographic methods were described by which this compound could be identified (1).The purpose of this paper is to present evidence which establishes the presence of ~-decalaetone in dried cream, dry whole milk, and evaporated milk.The significance of the presence of this flavor compound is discussed. EXPERIMENTAL PROCEDURE Extraction of the Flavor Compound.A. Dried cream.A commercial sample of dried cream, exhibiting a strong coconut-like flavor, was available in the laboratory.This product had been manufactured in 1945 and had been sealed under vacuum and stored at room temperature for 10 years.The flavor stability of this product deserves special note.The reconstituted cream was remarkably free of any of the oily, tallowy character associated with the normal oxidative deterioration of dried milk products.According to the label on the can, the powder contained no preservatives or adulterants.The flavor of the reconstituted cream was described as "strong-coconut" and "like dry whole milk."A coconut-like concentrate was obtained by separating the fat from the dried product and then extracting the fat fraction in the same manner as that used in isolating ~-decalactone from butter oil (1).A quantitative recovery of fat from dried cream was obtained by Soxhlct type extrac-