Purpose: The purpose of this study was to evaluate the effect of using oregano essential oil (OEO) as a natural antibacterial and antioxidant in mayonnaise preparations with low-acidity.
Methods: The essential oil’s antioxidant activity was evaluated using the DPPH assay. Samples were also evaluated for acidity, pH and water activity during 8 weeks. All experiments were performed in triplicate, expressing the results as averages of the three readings. The antimicrobial effect of OEO against SE was studied to be applied in mayonnaise during storage at 8° or 30°C for 24 hours. The data were submitted to analysis of variance (ANOVA) with 95% significance level (P <0.05) and the Tukey test (P < 0.05) using the statistical software XLSTAT version 7.5.
Results: The results showed that oregano essential oil is rich in phenolic compounds, with good antioxidant activity and acts to protect mayonnaise against oxidation reactions. There were statistically significant differences in the IC50 results (control sample 326 mg/mL; OEO sample 111 mg/mL). OEO also was very efficient against Salmonella Enteritidis.There were no colonies counted on the samples of mayonnaise with OEO, for control sample (without OEO), the results were 3.20; 3.10; 3.18 and 3.09 log CFU/g of mayonnaise for the times 0, 2, 4 and 24 hours respectively.
Significance: These results indicate that the use of OEO as a biopreservative (natural antimicrobial and antioxidant) can enhance food safety, serving as an additional barrier in helping the Good Manufacturing Practices and the Hazard Analysis Critical Control Point program, fundamental to food safety.