# Edible Films Based on Ovine Second Cheese Whey with Oregon Essential Oil
## 3 Results and Discussion
### Color  
The CIE \(L^{*}a^{*}b^{*}\) color values, total color difference (\(\Delta E\)), opacity and whiteness index are shown in Table 3. Two-way ANOVA of the color of the films with the WPI-SCW mixture are shown in Table 4. The substitution of WPI by SCW significantly influenced the color parameters. The addition of SCW to the films decreased the value of \(L^{*}\) but only in samples without essential oil. The substitution of WPI by SCW increased the values of \(a^{*}\) and \(b^{*}\) in the films with or without EO. Total color difference (\(\Delta E\)) presented significant changes with the addition of SCW, with values of \(\Delta E\) that are higher than 2. This indicates that inexperienced observers can detect differences in the films with different proportions of WPI and SCW [34]. The color parameters of the films (\(L^{*}\), \(a^{*}\), \(b^{*}\)) and their opacity were not influenced by the addition of EO. However, [PERSON] et al. [16] observed that the incorporation of oregano essential oil decreased the lightness, whereas the influence in \(a^{*}\) and \(b^{*}\) are contradictory because it was found to depend on the amount of EO. The decrease of lightness was attributed to the fact that the oregano essential oil was included in small globules in the structure of the films. The different homogenizers in the preparation of the mixtures and the different brands used could influence both the distribution of EO and the color of the films.  
\begin{table}
\begin{tabular}{c c c c c c c} \hline
**Film** & \(L^{*}\) & \(a^{*}\) & \(b^{*}\) & \(\Delta E\) & **Opacity** & **Whiteness** \\ \hline WPI & 92.96 \(\pm\) 0.49 c & \(-\)3.04 \(\pm\) 0.09 ab & 3.15 \(\pm\) 2.04 a & 0.00 \(\pm\) 0.00 a & 14.91 \(\pm\) 0.25 a & 91.59 \(\pm\) 1.19 d \\ WS 2:1 & 90.08 \(\pm\) 1.35 b & \(-\)3.11 \(\pm\) 0.10 a & 7.04 \(\pm\) 1.59 ab & 4.92 \(\pm\) 2.18 ab & 18.55 \(\pm\) 0.22 b & 87.43 \(\pm\) 1.92 cd \\ WS 1:1 & 88.16 \(\pm\) 1.25 ab & \(-\)2.89 \(\pm\) 0.13 abc & 9.86 \(\pm\) 2.16 bcd & 8.33 \(\pm\) 4.13 bc & 22.00 \(\pm\) 1.18 de & 84.30 \(\pm\) 2.26 bc \\ WS 1:2 & 88.51 \(\pm\) 0.97 ab & \(-\)2.46 \(\pm\) 0.32 bc & 13.00 \(\pm\) 2.27 cd & 10.83 \(\pm\) 2.93 bcd & 26.82 \(\pm\) 0.59 g & 82.46 \(\pm\) 2.22 b \\ SCW & 86.16 \(\pm\) 1.32 a & \(-\)1.10 \(\pm\) 0.52 d & 18.11 \(\pm\) 2.21 e & 16.58 \(\pm\) 2.22 d & 23.81 \(\pm\) 1.79 g & 77.17 \(\pm\) 2.48 a \\ WS 2:101 & 88.60 \(\pm\) 1.00 ab & \(-\)3.06 \(\pm\) 0.09 b & 8.86 \(\pm\) 1.45 bc & 7.21 \(\pm\) 1.21 bc & 19.55 \(\pm\) 0.66 bd & 85.17 \(\pm\) 0.40 bc \\ WS 1:101 & 88.52 \(\pm\) 0.62 ab & \(-\)2.02 \(\pm\) 0.17 ab & 11.60 \(\pm\) 1.33 bcd & 9.54 \(\pm\) 2.37 bcd & 21.28 \(\pm\) 0.65 cde & 83.41 \(\pm\) 1.24 bc \\ WS 1:201 & 88.09 \(\pm\) 0.60 ab & \(-\)2.25 \(\pm\) 0.21 c & 14.67 \(\pm\) 1.68 de & 12.53 \(\pm\)1.65 d & 27.61 \(\pm\) 1.16 g & 80.96 \(\pm\) 1.59 ab \\ WS 2:102 & 88.82 \(\pm\) 0.74 b & \(-\)3.03 \(\pm\) 0.07 ab & 9.63 \(\pm\) 0.71 bc & 7.74 \(\pm\) 0.90 bc & 18.83 \(\pm\) 0.73 bc & 84.94 \(\pm\) 1.00 bc \\ WS 1:102 & 88.91 \(\pm\) 0.27 b & \(-\)2.85 \(\pm\) 0.15 bc & 11.52 \(\pm\) 1.07 bcd & 9.33 \(\pm\) 2.99 bc & 21.86 \(\pm\) 0.59 d & 83.75 \(\pm\) 0.84 bc \\ WS 1:202 & 88.44 \(\pm\) 0.12 ab & \(-\)2.58 \(\pm\) 0.16 abc & 13.15 \(\pm\) 1.54 cde & 11.01 \(\pm\) 1.70 bcd & 24.83 \(\pm\) 0.82 fg & 82.28 \(\pm\) 1.16 b \\ \hline \end{tabular}
\end{table}
Table 3: CIE \(L^{*}a^{*}b^{*}\) color parameters, total color difference (\(\Delta E\)), opacity and whiteness index (mean \(\pm\) SD) of the films described in the materials and methods section.