## 3 Results and Discussion
### Milk and IF Fatty Fraction  
The contents of the liposomesulating A (retinol) and E (\(\alpha\)-tocopherol), and of cholesterol (expressed as mg kg\({}^{-1}\)) in the ovine milk and IF1 and IF2 samples are reported in Table 5.  
The retinol, \(\alpha\)-tocopherol, and cholesterol contents found in whole milk samples (Table 5) are in agreement with those reported by other authors [7; 9; 10]. With respect to skimmed milk and retentate, whole milk is the IF component that provides the higher quantities of all molecules related to milk fat. Compared to IF1, IF2 obtained using higher amounts of whole milk, showed significantly higher values for these three parameters (\(p<0.05\)). Retinol and \(\alpha\)-tocopherol are two liposomesulating essential for human health. Retinol is the principal and most biologically active form of vitamin A and plays a central role in several biological processes during the growth and developmental stages of neonates, such as the functioning of the visual process and the immune system, and in maintaining \begin{table}
\begin{tabular}{l c c c c c} \hline \hline  & **Retentate \({}^{*}\)** & **Whole Milk** & **Skimmed Milk** & **IF1** & **IF2** \\  & **(_n = 6_)** & **(_n = 6_)** & **(_n = 6_)** & **(_n = 6_)** \\ \hline Ca & 44.1 \(\pm\) 0.3 \({}^{\rm e}\) & 180.6 \(\pm\) 6.6 \({}^{\rm b}\) & 192.3 \(\pm\) 7.8 \({}^{\rm a}\) & 64.0 \(\pm\) 1.6 \({}^{\rm d}\) & 122 \(\pm\) 7.9 \({}^{\rm c}\) \\ Mg & 11 \(\pm\) 2 \({}^{\rm b}\) & 17 \(\pm\) 1 \({}^{\rm a}\) & 19 \(\pm\) 1 \({}^{\rm a}\) & 8 \(\pm\) 1 \({}^{\rm c}\) & 12 \(\pm\) 1 \({}^{\rm b}\) \\ Na & 57 \(\pm\) 9 \({}^{\rm a}\) & 60 \(\pm\) 8 \({}^{\rm a}\) & 60 \(\pm\) 3 \({}^{\rm a}\) & 47 \(\pm\) 4 \({}^{\rm b}\) & 49 \(\pm\) 5 \({}^{\rm b}\) \\ K & 137 \(\pm\) 16 \({}^{\rm a}\) & 114 \(\pm\) 4 \({}^{\rm b}\) & 119 \(\pm\) 5 \({}^{\rm b}\) & 79 \(\pm\) 7 \({}^{\rm c}\) & 86 \(\pm\) 6 \({}^{\rm c}\) \\ P & 57.6 \(\pm\) 0.3 \({}^{\rm c}\) & 123.2 \(\pm\) 8.3 \({}^{\rm a}\) & 128.6 \(\pm\) 7.7 \({}^{\rm a}\) & 49.3 \(\pm\) 4.8 \({}^{\rm c}\) & 86.7 \(\pm\) 5.4 \({}^{\rm b}\) \\ S & 22 \(\pm\) 2 & 21 \(\pm\) 7 & 23 \(\pm\) 6 & 17 \(\pm\) 4 & 19 \(\pm\) 4 \\ B & \textless\text{}0.05 & 0.05 \(\pm\) 0.01 & 0.05 \(\pm\) 0.01 & 0.05 \(\pm\) 0.01 & 0.05 \(\pm\) 0.01 \\ Zn & 0.30 \(\pm\) 0.07 \({}^{\rm bc}\) & 0.50 \(\pm\) 0.13 \({}^{\rm ab}\) & 0.64 \(\pm\) 0.14 \({}^{\rm a}\) & 0.28 \(\pm\) 0.07 \({}^{\rm c}\) & 0.44 \(\pm\) 0.14 \({}^{\rm bc}\) \\ Cu & 0.05 \(\pm\) 0.00 & 0.08 \(\pm\) 0.06 & 0.09 \(\pm\) 0.06 & 0.10 \(\pm\) 0.04 & 0.09 \(\pm\) 0.06 \\ Mn & 0.06 \(\pm\) 0.08 & 0.06 \(\pm\) 0.05 & 0.05 \(\pm\) 0.06 & \textless\text{}0.05 & 0.09 \(\pm\) 0.10 \\ Fe & 0.09 \(\pm\) 0.04 & 0.14 \(\pm\) 0.06 & 0.18 \(\pm\) 0.06 & 0.12 \(\pm\) 0.11 & 0.15 \(\pm\) 0.06 \\ \hline \hline \end{tabular} \({}^{*}\)Retentate from ultrafiltration of skimmed whey. Different letters in a row indicate mean differences statistically significant at \(p<0.05\).  
\end{table} 
Table 4: Mineral composition (mg 100 g\({}^{-1}\)) of milk ingredients and of the two resulting liquid milk-derived formulations IF1 and IF2, to be used in the production of first stage (from 0 to 6 months of age) and follow-on (from 6 to 12 months of age) infant formulae, respectively (mean \(\pm\) SD). the integrity of epithelial tissues. It also acts as an antioxidant molecule. \(\alpha\)-Tocopherol is the prevalent and most biologically active form of vitamin E in milk. It acts as an antioxidant molecule and can prevent the formation of free radicals, protecting the lipids of various biological structures, such as cell membranes, from peroxidation processes [29; 30]. Usually, in commercial FMs, the vitamin content of milk derived ingredients is further integrated with blends of fat- and water-soluble vitamins. On the other hand, IF1 and IF2 can be considered the only sources of cholesterol in the final infant formulae.