Propolis extract (PE) at levels of 0.02, 0.05, 0.1, 0.2 and 0.4% \'NIW) was
evaluated as a natural antioxidant for sunflower oil in relation to some synthetic
antioxidant such as Butylated hydroxy toluene (BHD, Tertiary butylated hydroquinone
(TBHQ) and citric acid during storage at 50^oC/40 days. Oven stability, peroxide value, TBA and fatty acid analysis were chosen to
evaluate the effect of propolis extract as a natural antioxidant for sunflower oil. Oven stability (OS) of sunflower oil samples treated with PE was improved
over the control sample and synthetic antioxidants. It reached to 25 and 27 days at
the level of 0.2 and 0.4% (PE), respectively. Addition of PE retarded the development
of rancidity of the oil for a period of; at least more than three times of the control
sample. The peroxide value (PV) of sunflower oil samples gradually increased during
storage reaching its maximum level after 40 days except the control samples (35
days). TBA values of samples containing PE were lower than those of the control
throughout the storage period. The PE at the level of 0.2 and 0.4% were more
effective than synthetic antioxidant for retarding oxidative rancidity. Total saturated fatty acids of sunflower oil samples were slightly increased . through 40 days; a trend which corresponding by reduction of total unsaturated fatty
acids specially linoleic acid (C₁82). A marked decrease in the proportion of (C₁82) was
observed at the control than all of the other samples. The lowest reduction rate of
C₁82 (4.8%) was reported for sample containing 0.2% (PE). So, PE; at the level of
0.2% or above can be used as a natural antioxidant in prolonging the stability of
sunflower oil instead of synthetic ones.