QUANTITATION OF VOLATILE COMPOUNDS IN HEATED TRILINOLEIN BY STATIC HEADSPACE-CAPILLARY GAS-CHROMATOGRAPHY INFRARED-SPECTROSCOPY MASS-SPECTROMETRY

Static headspace and capillary gas chromatography/infrared spectroscop y-mass spectrometry were used to collect, separate, detect and quantit ate the oxidative and thermal decomposition products in heated trilino lein. Trilinolein without added antioxidants was heated in a deep fat fryer at 190 degrees C for 12 h each day for a total of 24 h until the amount of polymeric material in the oil exceeded 20%. The concentrati on of the volatile compounds in trilinolein, as well as the p-anisidin e values and polymer content, increased with an increase in heating ti me. After 24 h of heating, the concentrations of the major volatile co mpounds (>10 ppm) had increased as follows: pentane (33.4-398.7 ppm), pentanal (11.7-73.5 ppm), 1-pentanol (5.2-46.7 ppm), hexanal (67.6-346 .1 ppm), (E)-2-hexenal (12.9-87.6 ppm), (E)-2-heptenal (309.6-894.1 pp m), 1-octen-3-ol (35.2-150.2 ppm), formic acid (0-18.7 ppm), hexanoic acid (0-83.8 ppm), heptanal (2.5-29.5 ppm), 2-pentylfuran (29.2-146.9 ppm), (E)-2-octenal (26.4-347.2 ppm), (E)-2-octenal (26.4-347.2 ppm), (E)-2-nonenal (31.6-163.2 ppm), (E,Z)-2,4-decadienal (15.0-320 ppm) an d (E,E)-2,4-decadienal (43.1-1137.5 ppm).