Triple-channel comparative analysis of volatile flavour composition in raw whole and skim milk via electronic nose, GC-MS and GC-O

A novel triple-channel comparative analysis of volatile composition in raw whole and skim milk (RWM and RSM) was developed via an electronic nose (E-Nose), headspace solid-phase micro-extraction (HS-SPME) coupled with gas chromatography-mass spectrometry (GC-MS), and gas chromatography-olfactometry (GC-O). Volatile flavour compounds from RWM and RSM caused the differences in mouthfeel characteristics by the human sensors, and also affected consumer preference. Solid state sensor technology, an E-Nose, was applied to distinguish the differences in volatiles between RWM and RSM. Headspace volatiles adsorbed by HS-SPME fiber (CAR/PDMS) were detected by GC-MS. Aroma compounds were identified by GC-O. Nine and three compounds were found to be aroma-active compounds from RWM and RSM, respectively. Octanoic acid, butanoic acid, and 3-hydroxy-2-butanone were found to be the most important aroma-active compounds in RWM, while the most important aroma-active compound of RSM was octanoic acid.