## 3 Results and Discussion
### Influence of Commercial PET Packaging on Olive Oil Properties  
In the previous sections, it has been established that different treatments influenced the physicochemical and organoleptic properties of the analyzed oils. Additionally, analyses using FT-IR and DSC revealed that the PET containers used to hold the oils experienced deterioration due to thermal exposure and storage periods. The following presents some evidence of the influence of PET and its degradation on the modification of oil properties.  
\begin{table}
\begin{tabular}{l c c c c c} \hline \hline
**O04** & **Cd** & **Pb** & **Cu** & **Fe** & **Sb** \\ \hline T0a & 0.001 \(\pm\) 0.000 & 0.024 \(\pm\) 0.002 & 0.107 \(\pm\) 0.008 & 0.156 \(\pm\) 0.021 & 1.422 \(\pm\) 0.012 \\ T6 & 0.001 \(\pm\) 0.000 & 0.022 \(\pm\) 0.002 & 0.134 \(\pm\) 0.010 & 0.152 \(\pm\) 0.027 & 0.885 \(\pm\) 0.017 \\ t-Student (\(\alpha\) = 0.05) & 0.005 & 0.236 & 0.007 & 0.676 & 0.000 \\ T0b & 0.001 \(\pm\) 0.000 & 0.139 \(\pm\) 0.011 & 0.126 \(\pm\) 0.010 & 1.538 \(\pm\) 0.041 & 1.075 \(\pm\) 0.032 \\ T12 & 0.003 \(\pm\) 0.000 & 0.132 \(\pm\) 0.010 & 0.118 \(\pm\) 0.009 & 1.410 \(\pm\) 0.096 & 1.317 \(\pm\) 0.018 \\ t-Student (\(\alpha\) = 0.05) & 0.000 & 0.358 & 0.291 & 0.167 & 0.011 \\ \hline
**O1** & **Cd** & **Pb** & **Cu** & **Fe** & **Sb** \\ \hline T0a & 0.001 \(\pm\) 0.000 & 0.020 \(\pm\) 0.002 & 0.182 \(\pm\) 0.014 & 0.197 \(\pm\) 0.015 & 0.769 \(\pm\) 0.060 \\ T6 & 0.001 \(\pm\) 0.000 & 0.017 \(\pm\) 0.001 & 0.156 \(\pm\) 0.012 & 0.392 \(\pm\) 0.030 & 1.117 \(\pm\) 0.087 \\ t-Student (\(\alpha\) = 0.05) & 0.000 & 0.060 & 0.035 & 0.000 & 0.001 \\ T0b & 0.001 \(\pm\) 0.000 & 0.202 \(\pm\) 0.016 & 0.157 \(\pm\) 0.012 & 1.800 \(\pm\) 0.140 & 1.201 \(\pm\) 0.094 \\ T12 & 0.004 \(\pm\) 0.000 & 0.145 \(\pm\) 0.011 & 0.130 \(\pm\) 0.010 & 1.551 \(\pm\) 0.121 & 1.643 \(\pm\) 0.128 \\ t-Student (\(\alpha\) = 0.05) & 0.000 & 0.002 & 0.014 & 0.004 & 0.002 \\ \hline \hline \end{tabular}
\end{table}
Table 11: Concentration of heavy metals in mild (O04) and intense (O1) olive oils after exposure according to Experiments A and B.  
The obtained results after exposure, according to Experiments A and B for O04 and O1 of the carbonyl index as indicators of plastic degradation and the sensory analysis as indicators of oil alteration, are shown in Figures 4 and 5.  
In these figures, it is observed that the carbonyl index increases with the treatments compared to the control sample in all cases. This could explain why compounds including the carbonyl functional group (C=O) mentioned earlier could transfer to the analyzed olive oils, causing undesirable flavors and aromas. In this case, the sensory analysis revealed a decrease in the \"fruity\" intensity in both oils and an increase in the \"rancid\" defect during the treatments for O04 and with the more severe treatments for O1, thereby showing the loss of quality and increased deterioration in both oils.  
Furthermore, it was observed that under conditions of greater plastic deterioration, there is a greater diffusion of heavy metals, such as antimony (Sb), which is known to be present in it. In this context, PET O1 showed a reduction in the percentage of crystallinity  
Figure 4: Overlay of carbonyl index and sensory descriptors of mild olive oil (O04).  
Figure 5: Overlay of carbonyl index and sensory descriptors of intense olive oil (O1).  
(Wc) compared to the control sample after the treatments, with results of 9.08% and 6.02%, respectively (Table 10). O1 showed a higher concentration of Sb compared to the control sample after applying the treatments (Figure 5). Therefore, this observation could be explained by the fact that the applied treatments caused greater amorphization in the PET structure, which in turn, would facilitate the diffusion of compounds like Sb [78].