Farag, R., Mahmoud, E., Bassluny, A. (2004). USE OF CRUDE OLIVE LEAVE JUICE AS A NATURAL ANTIOXIDANT FOR THE STABILITY OF HEATED SUNFLOWER OIL. Journal of Soil Sciences and Agricultural Engineering, 29(7), 4265-4280. doi: 10.21608/jssae.2004.241942
R.S. Farag; Ebtsam A. Mahmoud; Amany M. Bassluny. "USE OF CRUDE OLIVE LEAVE JUICE AS A NATURAL ANTIOXIDANT FOR THE STABILITY OF HEATED SUNFLOWER OIL". Journal of Soil Sciences and Agricultural Engineering, 29, 7, 2004, 4265-4280. doi: 10.21608/jssae.2004.241942
Farag, R., Mahmoud, E., Bassluny, A. (2004). 'USE OF CRUDE OLIVE LEAVE JUICE AS A NATURAL ANTIOXIDANT FOR THE STABILITY OF HEATED SUNFLOWER OIL', Journal of Soil Sciences and Agricultural Engineering, 29(7), pp. 4265-4280. doi: 10.21608/jssae.2004.241942
Farag, R., Mahmoud, E., Bassluny, A. USE OF CRUDE OLIVE LEAVE JUICE AS A NATURAL ANTIOXIDANT FOR THE STABILITY OF HEATED SUNFLOWER OIL. Journal of Soil Sciences and Agricultural Engineering, 2004; 29(7): 4265-4280. doi: 10.21608/jssae.2004.241942
USE OF CRUDE OLIVE LEAVE JUICE AS A NATURAL ANTIOXIDANT FOR THE STABILITY OF HEATED SUNFLOWER OIL
1Biochemistry Department, Faculty of Agriculture. Cairo University, Giza, Egypt.
2Department of Food Technology, Agriculture Research Center, Ministry of Agriculture, Giza, Egypt.
Abstract
Olive leaves (Kronakii cultivar) were obtained from the annual pruning of olive trees and pressed to obtain a crude juice. An aliquots from the concentrated crude olive leave juice, represent 400, 600, 1600 and 2400 ppm as polyphenols, were added to sunflower oil. Samples of sunflower oil mixed with olive leaves juice were intermittent heated at 180°C ± 5 for 5 hr I day and the heating process was repeated for 5 consecutive days. A control experiment was performed where butylated hydroxyl toluene (BHT) at 200 ppm was added to sunflower oil perior to intermittent heating in order to compare the antioxidant efficiency between the natural polyphenolics of olive juice and synthetic antioxidant BHT.
Some physical (refractive index, smoke point, color and viscosity) and chemical (acid value, peroxide value, iodine value, thiobarbituric acid value, saponification number, oxidized fatty acid level and polymer content) constants for the unheated and heated sunflower oil were determined. The data indicated that the addition of olive leave juice to heated sunflower oil induced remarkable antioxidant activity and at 800 ppm level were superior to that of BHT is increasing sunflower oil stability.