## 3 Results and Discussion
### Milk and Yoghurt Proximate Composition  
Milk composition as well as physicochemical characteristics are presented in Table 4. There were no significant differences (\(p>0.05\)) in the contents of protein, fat and lactose whereas highly significant differences (\(p<0.01\)) were observed in the total solids content. These differences are related to the content of ash indicating that inclusion of either unprocessed or processed orange peels (UOP and POP treatments) led a higher ash content. The protein and fat content of the milk were similar to the values reported by the Hellenic Agricultural Organisation DIMITRA [59] for raw sheep milk produced both in the Regional Unit of Pella and across the entire country during the study period (March-May 2023). Specifically, protein content was 4.36 g/100 g in the Regional Unit of Pella and 4.35 g/100 g for the entire country, while fat content was 5.28 g/100 g and 5.33 g/100 g, respectively. In terms of lactose content, all treatments showed higher levels compared to the milk produced in the Regional Unit of Pella (4.59 g/100 g). Notably, milk from the UOP and POP treatments exceeded the lactose content reported for milk produced nationwide (4.67 g/100 g). The milk composition fell within the range reported by [PERSON] et al. [60] for milk analysed both at the farm and at the dairy plant in northwestern Greece. It was also consistent with the findings of [PERSON] et al. [61] for milk from ewes raised under an intensive production system. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline  & \multicolumn{4}{c}{**Treatment**} \\ \cline{2-6}
**Component** & **Control** & **UOP** & **POP** & **SEM** & **Significance** \\  & **(n = 4)** & **(n = 4)** & **(n = 4)** & & \\ \hline Protein (\%) & 5.27 & 5.58 & 5.31 & 0.083 & NS \\ Fat (\%) & 5.91 & 6.77 & 6.25 & 0.169 & NS \\ Lactose (\%) & 4.66 & 4.72 & 4.78 & 0.024 & NS \\ Total solids (\%) & 16.68 a  & 17.90 b  & 17.17 ab  & 0.186 & ** \\ FPD (-\({}^{\circ}\)C) & 0.542 b  & 0.561 a  & 0.557 a  & 0.027 & ** \\ pH & 6.73 & 6.78 & 6.71 & 0.014 & NS \\ Titratable acidity (g lactic acid/100 g milk) & 0.148 & 0.146 & 0.153 & 0.004 & NS \\ Electrical Conductivity (mS/cm) & 3.92 & 4.03 & 3.99 & 0.022 & NS \\ Refractive index (nD20) & 1.3531 & 1.3539 & 1.3537 & 0.000 & NS \\ Brix (\({}^{\circ}\)Bx) & 13.38 & 13.88 & 13.93 & 0.104 & NS \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Milk proximate composition and physicochemical characteristics. \begin{table}
\begin{tabular}{c c c c} \hline \hline  & \multicolumn{3}{c}{**Treatment**} \\ \cline{2-4}
**Microorganism** & **Control** & **UOP** & **POP** \\  & **(n = 12)** & **(n = 12)** & **(n = 12)** \\ \hline _Coliform_ spp. (log\({}_{10}\) CFU/g) & \textless{}DL & \textless{}DL & \textless{}DL \\ _Staphylococcus aureus_ (log\({}_{10}\) CFU/g) & \textless{}DL & \textless{}DL & \textless{}DL \\ _Escherichia coli_ (log\({}_{10}\) CFU/g) & \textless{}DL & \textless{}DL & \textless{}DL \\ Moulds and yeasts (log\({}_{10}\) CFU/g) & \textless{}DL & \textless{}DL & \textless{}DL \\ _Salmonella_ spp. (Presence/Absence) & Absence & Absence & Absence \\ \hline UOP = Unprocessed orange peels; POP = Processed orange peels; DL = detection limit; DL = 1.0 log CFU/g for _Caliform_ spp. _Escherichia coli_, moulds and yeasts (pouring inoculation method) and 2.0 log CFU/g for _Staphylococcus aureus_ (spreading inoculation method). & \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Yoghurt microbial quality. Milk from ewes in the Control group showed a significantly higher freezing depression point (\(p<0.05\)). The FPD values for milk from the UOP and POP treatments fell within the reported range of \(-0.547\)\({}^{\circ}\)C to \(-0.588\)\({}^{\circ}\)C [60] while milk from the Control group displayed an even higher FPD. The FPD indicates extraneous water in milk, but since milk from a research farm was used in this study, any intentional water addition that raises the freezing point toward 0 \({}^{\circ}\)C is eliminated.