Accurate determination of volatile-flavor components in bos grunniens milk by high-throughput dynamic headspace gas chromatographic-mass spectrometry

A dynamic headspace (DHS) with DVB/CAR/PDMS trapping materials was coupled to a gas chromatography-mass spectrometry for the separation and identification of volatile-flavor compounds in bos grunniens (yak) milk. The principal components analysis coupled with response surface methodology optimized the main variables of the device (10 g sample quality, 5 min desorption time, 3.0 g adding sodium chloride, 72 degrees C extraction temperature, 28 min pre-equilibrium time and 86 min extraction time). Total 235 volatile components were identified. The limit of detections and quantifications of volatile components were 0.01-5.35 mg kg(-1) and 0.01-9.41 mg kg(-1), respectively, with relative standard deviation from 0.2% to 6.4%. The method performed well during volatile-flavor components analysis from the yak milk sample, producing excellent extraction parameters for the volatile components. Eighty-two volatile components identified in yak milk belonged to a broad range of chemical classes (ketones, aldehydes, aromatics, acids, alkanes, and estes), and 73 of them were at trace levels. Meanwhile, using gas chromatography-olfactometry technique, 11 volatile components were identified as contributors to the aroma of yak milk. In conclusions, a sensitive, convenient and reliable method was developed for the accurate determination of volatile-flavor compounds in yak milk utilizing DHS-GC/MS analyses. (C) 2019 Elsevier B.V. All rights reserved.