| The thermal oxidation volatile products of four vegetable oils with different fatty acid compositions (palm oil, rapeseed oil, sunflower seed oil and linseed oil)heating at 120, 150, 180?℃ were analyzed by headspace solid phase micro-extraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS). The results showed that the thermal oxidation volatile products of each vegetable oil under different heating temperatures had little difference, while great difference was found in the thermal volatile products of different vegetable oils. The common thermal oxidation volatile products of the four vegetable oils mainly were 1-octen-3-ol, n-octanol, n-hexanal, (Z)-2-heptenal, nonanal, trans-2-octenal, trans-2-nonanal, trans-2-decenal, 2-undecenal, (E,E) -2,4-decadienal, formic acid, pentanoic acid, hexanoic acid, heptanoic acid, octanoic acid and nonanoic acid. The contents of (E,E)-2,4-decadienal in palm oil, rapeseed oil, sunflower seed oil and linseed oil reached 200.64, 41468, 579.06 mg/kg and 54.72 mg/kg respectively when heating at 120?℃ for 36 h. (E,E)-2,4-decadienal and hexanoic acid could be used as characteristic volatile substances to assess the oxidation degree of common vegetable oils. |
