# Edible Films Based on Ovine Second Cheese Whey with Oregon Essential Oil
## 3 Results and Discussion
### Water Vapor Permeability, Thickness, Dry Matter Content, Solubility and Density
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multirow{2}{*}{**Film**} & **WVP** & **Thickness** & **Dry Matter** & **Solubility** & **Density** \\  & **(ng s\({}^{-1}\) m\({}^{-1}\) Pa\({}^{-1}\))** & **\(\mu\)m** & **(g/100 g)** & **(\% D.M.)** & **(g/cm\({}^{3}\))** \\ \hline WPI & 0.156 \(\pm\) 0.04 & 150.67 \(\pm\) 58.66 & 57.77 \(\pm\) 0.9 a & 81.44 \(\pm\) 0.94 d & 1.43 \(\pm\) 0.15 a \\ WS 2:1 & 0.135 \(\pm\) 0.05 & 166.33 \(\pm\) 40.27 & 63.34 \(\pm\) 1.7 ab & 79.04\(\pm\) 3.22 cd & 1.73 \(\pm\) 0.27 ab \\ WS 1:1 & 0.089 \(\pm\) 0.01 & 131.83 \(\pm\) 33.45 & 65.59 \(\pm\) 2.04 b & 78.86 \(\pm\) 2.85 cd & 2.07 \(\pm\) 0.06 ab \\ WS 1:2 & 0.104 \(\pm\) 0.03 & 172.33 \(\pm\) 40.55 & 66.69 \(\pm\) 2.24 b & 77.68 \(\pm\) 2.44 bcd & 1.49 \(\pm\) 0.23 a \\ SCW & 0.141 \(\pm\) 0.03 & 160.17 \(\pm\) 16.37 & 66.79 \(\pm\) 1.20 b & 66.49 \(\pm\) 3.64 a & 1.98 \(\pm\) 0.16 ab \\ WS 2:1O1 & 0.137 \(\pm\) 0.05 & 124.17 \(\pm\) 11.51 & 67.93 \(\pm\) 0.55 b & 71.54 \(\pm\) 0.99 ab & 3.27 \(\pm\) 0.06 b \\ WS 1:1O1 & 0.141 \(\pm\) 0.009 & 173.83 \(\pm\) 5.30 & 66.34 \(\pm\) 0.53 b & 74.59 \(\pm\) 0.27 abcd & 1.76 \(\pm\) 0.22 ab \\ WS 1:2O1 & 0.147 \(\pm\) 0.03 & 184.00 \(\pm\) 38.94 & 63.86 \(\pm\) 1.00 b & 74.05 \(\pm\) 1.95 abcd & 1.69 \(\pm\) 0.58 ab \\ WS 2:1O2 & 0.120 \(\pm\) 0.03 & 139.67 \(\pm\) 25.15 & 63.33 \(\pm\) 1.68 ab & 80.16 \(\pm\) 4.43 cd & 2.27 \(\pm\) 0.73 ab \\ WS 1:1O2 & 0.102 \(\pm\) 0.003 & 123.00 \(\pm\) 17.32 & 66.56 \(\pm\) 2.97 b & 74.12 \(\pm\) 6.64 abcd & 2.53 \(\pm\) 1.11 ab \\ WS 1:2O2 & 0.117 \(\pm\) 0.007 & 142.33 \(\pm\) 6.25 & 64.83 \(\pm\) 4.25 b & 68.48 \(\pm\) 2.98 ab & 2.11 \(\pm\) 0.96 ab \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Water vapor permeability (WVP), thickness, dry matter (D.M. ), solubility and density (mean \(\pm\) SD) of films described in the materials and methods section. \begin{table}
\begin{tabular}{l l l l} \hline \hline  & & \multicolumn{3}{c}{**Two-Way ANOVA**} \\ \hline  & & **F** & **_p_ Value** \\ \hline WVP & Proportion WPI/SCW & 0.98 & 0.393 \\  & Addition of OE & 3.40 & 0.056 \\  & Interaction & 0.69 & 0.609 \\ \hline Thickness & WPI/SCW & 2.05 & 0.158 \\  & OE & 2.21 & 0.139 \\  & Interaction & 2.07 & 0.127 \\ \hline Dry matter & WPI/SCW & 0.88 & 0.432 \\  & OE & 0.65 & 0.534 \\  & Interaction & 2.60 & 0.071 \\ \hline Solubility & WPI/SCW & 2.57 & 0.104 \\  & OE & 6.01 & **0.010** \\  & Interaction & 3.65 & **0.024** \\ \hline Density & WPI/SCW & 2.78 & 0.089 \\  & OE & 2.18 & 0.141 \\  & Interaction & 2.54 & 0.076 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Two-way ANOVA of water vapor permeability (WVP), thickness, dry matter, solubility and density of WS films. OE, though other researchers have indicated that essential oil addition can increase the dry matter content of the films [16; 33]. Significant effects of the addition of EO and significant interactions between this incorporation and the substitution of WPI by SCW in the water solubility of the films were observed. In the films without EO, the addition of SCW caused a decrease in the water solubility of the films, with the films with only SCW showing significantly lower values than the other films. This result could be due to the way in which SCW has higher levels of fat than WPI and the way in which the hydrophobic properties of lipids can decrease the water solubility of the films. The water solubility of proteins is also related to the protein structure and the bonds among proteins [17]. The denatured state of the SCW proteins probably increased the amount of intermolecular disulfide bonds, which made the SCW films more resistant to solubilization in water. The substitution of WPI by SCW also significantly decreased the solubility of the films in the films with 2% of EO but this was not observed in films with 1% of EO. This different effect of the substitution of WPI by SCW in films with different concentration of EO should be investigated in future experiments.