The Effects of Pistachio Oil on Oxidative Stability of Sunflower Oil under Accelerated Oxidation Conditions

Nowadays, identifying the natural ways of preventing food deterioration due to the deleterious effects of synthetic additives has gained high significance. In this study, the effects of pistachio oil (PO), as a natural antioxidant, on the oxidative stability of sunflower oil (SFO) have been evaluated under accelerated oxidation conditions.

The antioxidant properties of unrefined SFO and PO were evaluated using the 2, 2-diphenyl-1-picrylhydrazyl (DPPH) method. The peroxide value (PV), thiobarbituric acid-reactive substances (TBARS), and the TOTOX value of SFO supplemented with the concentrations of 0.1, 0.2, and 0.4% of PO (T3, T4, and T5 treatments, respectively) were assessed as the oxidation indices, over 30 days. In addition, SFO alone and SFO in combination with butylated hydroxytoluene (BHT) were considered as negative and positive controls (T1 and T2 treatments), respectively. The statistical analysis of the indices was carried out using the one-within one-between ANOVA.

Treatments with 0.2 and 0.4% of PO delayed SFO oxidation for 20 days through their antioxidant contents, but the treatment with 0.1% of PO increased SFO oxidation after 30 days. The increase by the later might be due to the pro-oxidant nature of PO. It is worth noting that the high concentrations of PO (0.2 and 0.4%), a generally recognized as a safe (GRAS) additive, showed stronger oxidation-inhibitory effects than the authorized concentration of BHT (0.02%) (P 0.05).

In conclusion, it was identified that the use of PO, as a natural antioxidant, was effective in the prevention of SFO oxidation.