Abstract
In the manufacture of sesame seed oil, sesame seeds are roasted by various methods with the consequent emission of the characteristic roast-flavor. Roasting is the key step in sesame seed oil manufacture since it is the primarary determinant of flavor quality and intensity. The effects of fire blast-roasting and far infrared radiation-roasting on the formation of volatile flavor compounds in sesame seed oil were examined in this study. Volatile compounds were separated from sesame seed oil by steam distillation under reduced pressure and adsorptive column concentration and analysed by GC and GC-MS. Quantitative GC data for 37 volatiles of 29 sesame seed oil samples were examined by principal components analysis (PCA). The first principal component (PC1) 47.5% and PC2 14.3% of variance in the GC data. Two oils from fire blast-roasted sesame seeds and far infrared radiation-roasted sesame seeds could be distinguished each other on PC1 and PC2 scatter diagrams. Individual oil could be plotted as a function of roasting degree. Factor loadings in PCA indicated 15 volatiles to increase roasting degree for fire blast-roasted oils, but 11 volatiles to each increase with roasting degree of far infrared radiation-roasted oils.
