## 3 Results and Discussion
### Physicochemical Characterisation of Tuma Cheeses  
The physicochemical traits of the cheeses are reported in Table 3. The chemical composition of cheese in terms of ash, protein, and fat was not affected by the addition of OEO. Additionally, chemical components of the processed cheeses were in the ranges registered in other investigations [18; 70; 71].  
The lowest hardness, expressed as resistance to compression, was found in the experimental production cheeses (ECPO100 and ECP0200), which reflects the lower consistency of their paste, justified by their higher humidity and then by their lower DM percentage.  
Statistically significant differences were obtained for all cheese color indexes. Indeed, experimental products at both OEO levels (ECPO100 and ECP0200) showed higher values of lightness (L*) and redness (a*) and a corresponding lower yellow index (b*) compared to CCP cheeses. These results were expected considering the dark color of the extract attributed to the chlorophyll content in oregano. Furthermore, [PERSON] et al. [72], who added OEOs to milk, found that the color varied more consistently at increasing OEO  
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline  & \multicolumn{4}{c}{**Samples**} & \multicolumn{1}{c}{**SEM**} & \multicolumn{1}{c}{\(p\)**-Value**} \\ \hline  & **CCP** & **ECPO100** & **ECPO200** & **SEM** & \(p\)**-Value** \\ \hline Cheese weight at 48 h, kg & 2.93 & 3.52 & 3.61 & 2.244 & 0.2222 \\ Cheese yield at 48 h, g/100 g & 14.63 & 15.97 & 16.45 & 0.350 & 0.1206 \\ Cheese yield at 48 h, g/100 g & 8.65 & 9.02 & 9.34 & 0.208 & 0.1145 \\ dry matter & & & & & \\ Dry matter (DM), \% & 59.16 \({}^{\text{a}}\) & 56.52 \({}^{\text{b}}\) & 56.79 \({}^{\text{b}}\) & 0.608 & \textless{}0.0001 \\ Ash, \% DM & 6.54 & 6.81 & 6.53 & 0.414 & 0.8531 \\ Protein, \% DM & 43.34 & 42.39 & 43.24 & 1.413 & 0.5178 \\ Fat, \% DM & 45.92 & 45.65 & 42.20 & 4.846 & 0.8041 \\ pH & 5.52 & 5.23 & 5.21 & 0.260 & 0.6878 \\ Water activity, a\({}_{\text{w}}\) & 0.971 \({}^{\text{b}}\) & 0.979 \({}^{\text{ab}}\) & 0.986 \({}^{\text{a}}\) & 0.015 & 0.0267 \\ Hardness, N/mm\({}^{\text{2}}\) & 0.451 \({}^{\text{a}}\) & 0.300 \({}^{\text{b}}\) & 0.347 \({}^{\text{ab}}\) & 0.041 & 0.0137 \\ Lightness L* & 83.27 \({}^{\text{b}}\) & 86.91 \({}^{\text{a}}\) & 86.12 \({}^{\text{a}}\) & 1.0988 & 0.0005 \\ Redness a* & \(-\)3.551 \({}^{\text{b}}\) & \(-\)3.161 \({}^{\text{a}}\) & \(-\)3.078 \({}^{\text{a}}\) & 0.5096 & 0.0014 \\ Yellowness b* & 12.96 \({}^{\text{a}}\) & 12.48 \({}^{\text{ab}}\) & 11.94 \({}^{\text{b}}\) & 1.4333 & 0.1111 \\ TEAC, mmol/kg DM & 55.51 \({}^{\text{b}}\) & 68.26 \({}^{\text{b}}\) & 98.25 \({}^{\text{a}}\) & 4.763 & 0.0005 \\ POV, mEq O\({}_{2}\)/kg fat & 2.39 \({}^{\text{b}}\) & 3.14 \({}^{\text{a}}\) & 2.81 \({}^{\text{ab}}\) & 0.148 & 0.0089 \\ TBARs, mg MDA/kg DM & 0.066 \({}^{\text{c}}\) & 0.109 \({}^{\text{b}}\) & 0.172 \({}^{\text{a}}\) & 0.006 \(<\)0.0001 \\ \hline \hline \end{tabular}  
* Results indicate mean values of determinations carried out in duplicate for each of the two independent cheese making processes. Abbreviations: CCP, control cheese product inoculated with the milk starter cultures (MSC); ECP0100, experimental cheese product inoculated with MSC + 100 \(\mu\)L/L of oregano essential oils (OEOs); ECP0200, experimental cheese product inoculated with MSC + 200 \(\mu\)L/L of OEOs; SEM, standard error of the mean. On the row: \({}^{\text{a}}\), \({}^{\text{b}}=p<0.05\).  
\end{table}
Table 3: Physicochemical and antioxidant traits of Tuma cheeses.  
concentrations. However, the color indexes recorded in CCP cheeses were within the ranges observed for this type of cheese [18; 36].