EFFECT OF TOMATO PEEL PIGMENTS AND SOME NATURAL ANTIOXIDANTS ON OXIDATIVE STABILITY OF UNFLOWER OIL.

Tomato peel pigments (more than 90% lycopene) areexcellent antioxidant which can protect the human health from therisk of dangerous diseases. Different concentrations of lycopene pigments extracted by sunflower oil were used to improve thestability of this oil. Moreover a-tocopherol as well as 8-carotene were used as natural antioxidants. Also, BHT as one of the moslimportant synthetic antioxidant was used in different concentrations for comparison. The color of oil previously treated with lycopene and 8-carotene gave a high degree of red units, which increased gradually by increasing the concentrations of lycopene and 0-carotene from 20 to 80 ppm, while oil treated with a- tocopherol and / or BHT showed no change. In addition, there was no change in the yellow units occurred in all examined samples. Regarding the natural antioxidants, the lycopene exhibit the best result (even with the lowest concentration,20ppm).The used average incubation period with this treatment was 10 h at 100°C .This incubation period regarded as 10.19 month at room temperature. The highest mean of induction period was 12.00h at 100°C ( it means about 12.23 month at room temperature) was scored by using 200 ppm of BHT. As for mixing of natural antioxidants, the best treatment was mixing 20 ppm of each of lycopene and 8-carotene. The induction period was 10.30 h at 100°C (it means about 10.50 month at room temperature).An obvious gradual decrease in lycopene was observed in tomato peels exposed to atmospheric condition for 5 weeks, compared to treatment of bottled oil which showed slight decrease.