Effect of mixing ratio and heat treatment on chemical properties for some types of vegetable oil

The experiment was conducted in the laboratories of the Department of Food Science - College of Agriculture - Tikrit University , the study aimed to measure the effect of the mixing ratio of vegetable oils and heat treatment on some of the chemical properties ,Three mixing ratios were identified. The sunflower oils, Rice Brane, flax, and sesame were used , than mixing process were made with sunflower oil being the main oil, and the remaining oils were added separately, at rates of 15%, 30% and 45%. The heat factor was used as a second factor for the experiment, and the values of the chemical properties of the oils were read at room temperature (RT) and at 150 ° C for 1 hour . The effect of these factors was observed on the values of acidity number, free fatty acids, iodine number, peroxide number, saponification number of studied oils and their mixtures. The highest pH value of sesame oil was 1.56 mg KOH / gm, while the lowest value was 0.262 mg KOH / gm in the sample of the Rice bran, while the free fatty acids had the highest value in the sesame oil sample, it reached 0.784% and the lowest was in the rice bran sample It reached 0.132%, and the iodine number treatment reached the highest values In the sample of flax oil, which amounted to 190 and the lowest in the sample, 15% flax oil + 85% sunflower oil reached 64, and the characteristic of peroxide number was also recorded significant differences between the values and recorded the highest value in the treatment 30% flax oil + 70% flower oil Sun reached 1.44 O2 / Kg and the lowest recorded for treatment is 30% Rice bran + 70% sunflower oil and it reached 0.93 O2 / Kg. We also note that the value of saponification number recorded its highest value in the treatment of flax oil and reached 194 mg KoH / g. As for the lowest value it was recorded In the treatment of 15% rice bran oil + 85% sunflower oil and reached 101 mg KoH / g, the heating processes led to significant changes in the values.