Rapid analysis of vegetable oil flavor quality by dynamic headspace capillary gas chromatography

Abstracts A rapid capillary gas Chromatographic headspace technique using a multiple purge and trap system was developed and applied for the determination of vegetable oil flavor quality. Oil volatiles were purged at 150°C for 20 min, collected over a Tenax trap and subsequently desorbed and reconcentrated in a series of two smaller traps. From the gas Chromatographic profile, three compounds, t‐2‐heptenal, t‐2‐octenal and t,t‐2, 4‐decadienal were selected for computation of the flavor score of individual oil samples. Analysis of the flavor quality of soybean oil by this technique demonstrated a very good correlation to the traditional sensory evaluation procedure. Good correlation was also observed for the flavor evaluation of corn oils. Precision, based on multiple analyses of known standard aldehydes, was shown to be better than 6%. The degree of Chromatographic efficiency obtained by this multiple concentration technique permitted the use of a short 25‐min Chromatographic run in the resolution of these aldehydes of interest. This approach reduced the overall analysis time of existing instrumental oil flavor techniques significantly.