Heat-Induced Volatile Compounds in Milk

Milk, preheated at 82 C for 30 rain, was heated to 146 C for four seconds and cooled to 5 C in a tubular heat exchanger. Immediately after heat treatment, the milk was vacuum distilled at 30 C in a semicontinuous, reduced pressure, glass apparatus. Raw milk was distilled in a similar nmnner for a control. Continuous liquid-liquid ethyl ether extractions were employed to recover the compounds from the aqueous distillates. Gas ehromatography~ mass spectrometry, infrared spectrophotometry, and odor conflrmation were used to characterize the compounds in the ethereal concentrates.