The Effect of Essential Oil of Thyme (Zataria multiflora boiss) on the Sensory Properties and Oxidative Stability of Mayonnaise

Nowadays essential oils are considered as substitutes for synthetic additives in food products. Since the lipid oxidation is the main chemical process affecting mayonnaise deterioration, in this research, the antioxidant activity of essential oil ofthyme(Zataria multiflora boiss)was determined for oxidative stability of treated mayonnaise (homogenized) during 6 months of storage.
The antioxidant activities of the essential oil of thyme(0-150 µg/g) were investigated by DPPH method. The efficiency of this essential oil (144.4 µg/g) as a natural antioxidant in mayonnaise was studied by peroxide, anisidine, totox and thiobarbituric acid values.
GC analysis of the essential oil resulted in the identification of forty compounds. The essential oil characterized by a high number of monoterpenes such as thymol and carvacrol. Regarding anti-oxidation, the investigated essential oil strongly reduced the DPPH radical (IC50=144.4 g/ml). This study confirms that the essential oil of thymepossessed antioxidant properties in vitro. The results showed that the treatments containing essential oil and TBHQ significantly reduced the oxidation (p<0.05), while the control sample was oxidized faster. The essential oil had a significant effect on taste, odor and overall acceptance, but no significant difference was observed in color and texture.
The results of the present experiments suggest that essential oil of thyme(Zataria multiflora boiss)can be used as a source of natural antioxidant for the application in food industries to prevent lipid oxidation particularly lipid-containing foods such as mayonnaise. Therefore, it can use as a natural antioxidant and flavoring compound in foods such as mayonnaise.