Possible Inclusion of Artifacts in Flavors Recovered Directly from Dried Whole Milk

Abstract

To determine possible sources of artifacts arising in collecting volatile flavors from dehydrated dairy products, a study was made of contributions derived from the components of a high-vacuum collection procedure.Volatiles from 115cm2 of silicone high vacuum grease, Apiezon-N grease, or Teflon gaskets, collected on a liquid nitrogen-cooled condenser by holding each material for 3 hr at 25C and 1-μ pressure, when added to 200ml of milk, were undetected by a trained taste panel. Under the same conditions, volatiles from silicone, neoprene, and buna-N gaskets and O-rings were easily detected, lowering the flavor score of the milk pronouncedly. Viton O-rings produced a borderline effect: 115cm2 of material lowered the flavor score of milk slightly, while the volatiles from 57cm2 could not be detected.The recovery process had a generally deleterious effect on dried whole milk. The magnitude of this effect varied from barely detectable with some powders to quite definite with one powder. This effect was shown to depend on the hydration of the powder, being absent when nonhydrated powders were treated otherwise identically.