## 3 Results and Discussion
### Physico-Chemical Properties of Mayonnaises
No significant differences (\(p<0.05\)) were found between MDSB5 and MDSB5B samples in terms of peroxide values throughout storage, and, therefore, the basil essential oil did not influence the susceptibility to oxidation of the mayonnaise. However, other studies  
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Time (Weeks)** & **MC** & **MBHT** & **MDSB2.5** & **MDSB5** & **MDSB5B** \\ \hline \multicolumn{6}{c}{pH} \\ \hline
0 & 3.60 \(\pm\) 0.02 \({}^{\text{aA}}\) & 3.62 \(\pm\) 0.03 \({}^{\text{aB}}\) & 3.65 \(\pm\) 0.02 \({}^{\text{bA}}\) & 3.66 \(\pm\) 0.03 \({}^{\text{bA}}\) & 3.66 \(\pm\) 0.02 \({}^{\text{bA}}\) \\
2 & 3.65 \(\pm\) 0.03 \({}^{\text{aAB}}\) & 3.68 \(\pm\) 0.02 \({}^{\text{aB}}\) & 3.66 \(\pm\) 0.03 \({}^{\text{aA}}\) & 3.67 \(\pm\) 0.02 \({}^{\text{aB}}\) & 3.67 \(\pm\) 0.02 \({}^{\text{aA}}\) \\
4 & 3.65 \(\pm\) 0.03 \({}^{\text{aB}}\) & 3.73 \(\pm\) 0.02 \({}^{\text{bC}}\) & 3.66 \(\pm\) 0.03 \({}^{\text{aA}}\) & 3.67 \(\pm\) 0.02 \({}^{\text{aB}}\) & 3.69 \(\pm\) 0.02 \({}^{\text{aB}}\) \\
6 & 3.68 \(\pm\) 0.03 \({}^{\text{aB}}\) & 3.78 \(\pm\) 0.02 \({}^{\text{bD}}\) & 3.66 \(\pm\) 0.03 \({}^{\text{aA}}\) & 3.69 \(\pm\) 0.02 \({}^{\text{aB}}\) & 3.78 \(\pm\) 0.02 \({}^{\text{bB}}\) \\
8 & 3.72 \(\pm\) 0.03 \({}^{\text{bC}}\) & 3.85 \(\pm\) 0.02 \({}^{\text{cE}}\) & 3.67 \(\pm\) 0.03 \({}^{\text{aA}}\) & 3.71 \(\pm\) 0.02 \({}^{\text{aB}}\) & 3.98 \(\pm\) 0.02 \({}^{\text{dC}}\) \\ \hline \multicolumn{6}{c}{Acid values (g/kg)} \\ \hline
0 & 0.90 \(\pm\) 0.03 \({}^{\text{c}}\) & 0.90 \(\pm\) 0.03 \({}^{\text{c}}\) & 0.84 \(\pm\) 0.04 \({}^{\text{b}}\) & 0.79 \(\pm\) 0.03 \({}^{\text{a}}\) & 0.87 \(\pm\) 0.03 \({}^{\text{b}}\) \\
2 & 1.23 \(\pm\) 0.04 \({}^{\text{d}}\) & 1.01 \(\pm\) 0.04 \({}^{\text{b}}\) & 1.12 \(\pm\) 0.04 \({}^{\text{c}}\) & 1.01 \(\pm\) 0.05 \({}^{\text{b}}\) & 0.90 \(\pm\) 0.03 \({}^{\text{a}}\) \\
4 & 1.68 \(\pm\) 0.05 \({}^{\text{e}}\) & 1.29 \(\pm\) 0.04 \({}^{\text{c}}\) & 1.40 \(\pm\) 0.04 \({}^{\text{d}}\) & 1.18 \(\pm\) 0.05 \({}^{\text{b}}\) & 1.27 \(\pm\) 0.05 \({}^{\text{a}}\) \\
6 & 2.24 \(\pm\) 0.11 \({}^{\text{d}}\) & 1.74 \(\pm\) 0.08 \({}^{\text{bC}}\) & 1.85 \(\pm\) 0.10 \({}^{\text{c}}\) & 1.63 \(\pm\) 0.09 \({}^{\text{b}}\) & 1.46 \(\pm\) 0.08 \({}^{\text{a}}\) \\
8 & 3.14 \(\pm\) 0.16 \({}^{\text{d}}\) & 2.47 \(\pm\) 0.10 \({}^{\text{bC}}\) & 2.64 \(\pm\) 0.14 \({}^{\text{c}}\) & 2.36 \(\pm\) 0.14 \({}^{\text{ab}}\) & 2.13 \(\pm\) 0.12 \({}^{\text{a}}\) \\ \hline \multicolumn{6}{c}{Peroxide values (meq/kg)} \\ \hline
0 & 2.20 \(\pm\) 0.12 \({}^{\text{aA}}\) & 1.80 \(\pm\) 0.08 \({}^{\text{cA}}\) & 1.20 \(\pm\) 0.14 \({}^{\text{bA}}\) & 0.60 \(\pm\) 0.10 \({}^{\text{aA}}\) & 0.60 \(\pm\) 0.10 \({}^{\text{aA}}\) \\
2 & 2.50 \(\pm\) 0.23 \({}^{\text{cAB}}\) & 1.90 \(\pm\) 0.17 \({}^{\text{bA}}\) & 1.60 \(\pm\) 0.21 \({}^{\text{aB}}\) & 1.50 \(\pm\) 0.24 \({}^{\text{aB}}\) & 1.40 \(\pm\) 0.24 \({}^{\text{aB}}\) \\
4 & 2.90 \(\pm\) 0.32 \({}^{\text{bC}}\) & 1.90 \(\pm\) 0.34 \({}^{\text{aA}}\) & 2.00 \(\pm\) 0.2 have reported on the effectiveness of some essential oils in delaying the increase in the peroxide index in mayonnaise [13; 39]. The lipid oxidation of mayonnaise samples was estimated by the TBARS assay, and the results, expressed in mg MDA per kg sample, are presented in Table 2.  
The TBARS values continuously increased in all samples during the storage period, and the storage time had a significant effect on mayonnaise oxidation, considering that TBARS values significantly increased (\(p<0.05\)) from one time of sampling to another. However, a faster increase in the TBARS values was observed in the control samples as compared with the other samples. After 8 weeks of storage, TBARS values were significantly lower (\(p<0.05\)) in the MDSB2.5 sample compared with the control samples.