Monitoring oxidative stability and changes in key volatile compounds in edible oils during ambient storage through HS-SPME/GC-MS

Headspace solid-phase microextraction/gas chromatography-mass spectrometry (HS-SPME/GC-MS) analysis combined with relative odour activity value (ROAV)' was used to monitor changes in key volatile compounds in peanut oil, soybean oil, rapeseed oil, and linseed oil during ambient storage. Volatile composition and oxidation process were compared among edible oil samples. The differences in the volatile contents of edible oils led to their characteristic flavour. Aldehydes featured a relatively high content and low odour threshold and mainly contributed to the flavour of edible oils. The key flavour compounds included pentanal, hexanal, octanal, nonanal, trans-2-heptenal, and benzaldehyde, which are important oxidative degradation products of oleic acid and linoleic acid. The formation of key volatile oxidation compounds was affected by different oxidation processes during ambient storage. Certain aldehydes increased with oxidation level, whereas other aldehydes initially increased then decreased. Correlation analysis showed that the concentrations of several volatile compounds progressively increased during oxidation. The key volatile oxidation compounds formed during oil storage at ambient temperature are partly different from those generated at high temperatures. Volatile oxidation compounds can be a marker for monitoring the oxidation degree of edible oils during ambient storage.