## 3 Results
### Packaging Performance  
GTR values related to O\({}_{2}\) and CO\({}_{2}\) permeability were, respectively, 913 \(\pm\) 0.6 and 2230 \(\pm\) 17 cm\({}^{3}\)/m\({}^{2}\) day bar for untreated PP. The CAP treatment, either for 5 or 10 min, did not induce any significant changes on these parameters (data not reported), indicating that the controlled exposure of polymeric films to gas plasma did not produce important effects on their performance in terms of gas barrier properties. Table 4 shows the measured thermal properties of PP and PET before and after plasma exposure. The melting enthalpy of PP film did not change after exposure to gas plasma. Crystallinity percentage values ranging between 16.2-17.8% from the first scan, and 15.8-16.7% from the second scan, were recorded. A slight but not statistically significant temperature increase was measured during the second scans, highlighting the great thermal stability of PP films. Table 4 shows also the thermal parameter values related to PET material. In general, the values determined in the first scan are affected by the treatment undergone by the material during the production and use phases. These are the values that characterize the properties of the material. The values determined in the second scan give information on the intrinsic properties of the material, indicating, in this case, its tendency to recrystallize after melting and, therefore, highlighting the material behavior. In the present study, no significant differences between \(\Delta\)H\({}_{\text{m}}\) and X\({}_{\text{c}}\) parameters were observed, indicating that the exposure to cold plasma at the applied condition did not change the materials thermal performance. The EU regulation 10/2011 establishes that the acceptable limit for the global transfer of migrants from plastic materials intended to come into contact with food is equal to 10 mg/dm\({}^{2}\). The obtained results showed that the values of OM in PP and PET (Table 5) were well below the limits imposed by this regulation, and plasma exposure for 5 and 10 min did not modify this parameter. \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline  & \multicolumn{3}{c}{**First Heating**} & \multicolumn{3}{c}{**Second Heating**} \\ \hline  & \(\Delta\)**H\({}_{\text{m}}\) (J/g)** & **T\({}_{\text{m}}\) (\({}^{\circ}\)C)** & **X\({}_{\text{c}}\) (\%)** & **\(\Delta\)H\({}_{\text{m}}\) (J/g)** & **T\({}_{\text{m}}\) (\({}^{\circ}\)C)** & **X\({}_{\text{c}}\) (\%)** \\ \hline  & & & **PP** & & & \\ C & 33.6 \({}^{a}\)\(\pm\) 5.8 & 164.8 \({}^{a}\)\(\pm\) 0.6 & 16.2 \({}^{a}\)\(\pm\) 2.8 & 33.0 \({}^{a}\)\(\pm\) 4.8 & 165.5 \({}^{a}\)\(\pm\) 0.4 & 15.9 \({}^{a}\)\(\pm\) 2.3 \\ P5 & 36.9 \({}^{a}\)\(\pm\) 1.5 & 164.2 \({}^{a}\)\(\pm\) 0.6 & 17.8 \({}^{a}\)\(\pm\) 0.7 & 34.6 \({}^{a}\)\(\pm\) 1.6 & 165.4 \({}^{a}\)\(\pm\) 0.1 & 16.7 \({}^{a}\)\(\pm\) 0.8 \\ P10 & 34.8 \({}^{a}\)\(\pm\) 3.8 & 164.8 \({}^{a}\)\(\pm\) 0.7 & 16.8 \({}^{a}\)\(\pm\) 1.8 & 32.7 \({}^{a}\)\(\pm\) 3.3 & 165.5 \({}^{a}\)\(\pm\) 0.1 & 15.8 \({}^{a}\)\(\pm\) 1.6 \\  & & & **PET** & & & \\ C & 44.7 \({}^{a}\)\(\pm\) 7.8 & 248.8 \({}^{a}\)\(\pm\)0.5 & 27.6 \({}^{a}\)\(\pm\) 4.8 & 31.9 \({}^{a}\)\(\pm\) 5.6 & 248.6 \({}^{a}\)\(\pm\) 0.3 & 31.9 \({}^{a}\)\(\pm\) 5.5 \\ P5 & 51.2 \({}^{a}\)\(\pm\) 9.1 & 249.6 \({}^{a}\)\(\pm\) 0.2 & 31.3 \({}^{a}\)\(\pm\) 9.2 & 36.5 \({}^{a}\)\(\pm\) 7.2 & 248.3 \({}^{a}\)\(\pm\) 0.2 & 36.5 \({}^{a}\)\(\pm\) 7.2 \\ P10 & 52.3 \({}^{a}\)\(\pm\) 9.3 & 249.6 \({}^{a}\)\(\pm\) 0.1 & 32.9 \({}^{a}\)\(\pm\) 9.8 & 37.3 \({}^{a}\)\(\pm\) 6.6 & 248.1 \({}^{a}\)\(\pm\) 0.8 & 37.3 \({}^{a}\)\(\pm\) 6.6 \\ \hline \hline \end{tabular}  
* For each sampling time, different letters indicate significant differences (\(p<0.05\)) among untreated samples (C) and plasma-treated samples (P5 and P10).  
\end{table} 
Table 4: Thermal properties of untreated (C) and cold plasma-treated PP and PET samples for 5 (P5) and 10 (P10) min.