CHANGES IN VOLATILE COMPOUNDS OF BLACK CUMIN (NIGELLA SATIVA L.) SEED OIL DURING THERMAL OXIDATION

This study examined the oxidation stability and volatile compounds in samples of black cumin seed oil at 60 and 100 degrees C. Oxidative changes of black cumin oils followed by periodic determination of its conjugated dienes and trienes during accelerated conditions (60 and 100 degrees C). Black cumin oil showed high resistance to oxidation during thermal oxidation (60 and 100 degrees C). In addition to oxidative stability, volatile compounds in the oil were determined by headspace solid phase microextraction with gas chromatography-mass spectrometry analysis technique. The major componenent of the oil was p-cymene (44.77%) followed by thymoquinone (28.62%). Some volatile compounds were lost rapidly during thermal oxidation at the end of storage. Levels of thymoquinone, 4-terpineol, -longipinene, carvacrol, and isolongifolene reduced slowly and remained more stable during storage at two temperatures (60 and 100 degrees C).