ANTIOXIDANT ACTIVITY OF PUMPKIN SEED OIL AND ITS EFFECT ON OXIDATIVE STABILITY OF SUNFLOWER OIL MONITORED BY FTIR SPECTROSCOPY TECHNIQUE

The aim of this research was to evaluate the antioxidant activity of pumpkin seed oil obtained by cold pressed after roasting under specific conditions, as well as the study of its effect on the oxidative stability of sunflower oil. The first step was obtaining the pumpkin seed oil, then determining the total polyphenols, the antioxidant activity, density and the burning point. Investigation of its effect was checked by using pure sunflower oil, mixture of sunflower oil with 1% pumpkin seed oil and pure corn oil. All three prepared samples were exposed thermally at three serial cycles at the burning point for 8 hours, followed by cooling at room temperature for 16 hours. After each cycle their density and burning point were monitored, finally followed by FTIR Spectroscopy using intensity ratio as an excellent indicator of monitoring oxidative stability for edible oils. Oxidative stability results showed that the mixture of sunflower oil and pumpkin seed oil have higher stability than the two others: pure corn and sunflower oil. Higher thermal resistance of sunflower and pumpkin seed oil mixture is a result from pumpkin seed oil which has high antioxidant activity and this could be used as a natural antioxidant by the food industry