## 3 Results
### Oxidation Status  
The intensity of the oxidation process during accelerated storage and cooking treatment was followed through the determination of different chemical markers. Table 2 show Peroxide values and TBARs values. Peroxide values, indicating the intensity of the primary oxidation products formation, were 0 in raw coconut oil and also after the accelerated storage, reaching high values only after cooking (20.35 meg Q\({}_{2}\)/kg of product). A notable increase in PV during cooking coconut oil at 170 \({}^{\circ}\)C for 120 min has also been reported [44]. These results indicate higher stability of the lowest unsaturated oil during accelerated storage. However, in the case of the more unsaturated oils (rapeseed and grape seed), the behavior was very different, with medium values in raw samples (14.57 and 12.23 meg Q\({}_{2}\)/kg of product for rapeseed and grape seed, respectively), which increased with storage time (18.14-21.86 meg Q\({}_{2}\)/kg) and decreased for cooking conditions. Additionally, it has to be pointed out that the primary oxidation products would be degraded to secondary products explaining the lowest values of cooked samples found in rapeseed and grape seeds. [PERSON] et al. found a PV of 12.2 meg Q\({}_{2}\)/kg of product in raw cold press grape seed oils, with very significant increases during storage (60 \({}^{\circ}\)C 6 days) reaching a PV of 80 meg Q\({}_{2}\)/kg [45]. [PERSON] et al. obtained PV of 7.25 meg Q\({}_{2}\)/kg for raw grape seed oils, reaching 21.68 meg Q\({}_{2}\)/kg after 12 months at 4 \({}^{\circ}\)C and 58.24 meg Q\({}_{2}\)/kg after 12 days at 35 \({}^{\circ}\)C [46]. [PERSON] et al., analyzing the oxidative stability of selected edible refined oils (peanut, corn, rice bran, grapeseed, \begin{table}
\begin{tabular}{c c c c c c} \hline \hline  & **Oil** & **T0** & **T1** & **T2** & **T3** \\ \hline \multirow{3}{*}{PV} & Coconut & 0 \(\pm\) 0\({}^{\text{\tiny{AA}}}\) & 0 \(\pm\) 0\({}^{\text{\tiny{AA}}}\) & 0 \(\pm\) 0\({}^{\text{\tiny{AA}}}\) & 20.35 \(\pm\) 2.16\({}^{\text{\tiny{AA}}}\) \\  & Rapeseed & 14.57 \(\pm\) 1.02\({}^{\text{\tiny{IC}}}\) & 16.30 \(\pm\) 4.69\({}^{\text{\tiny{IC}}}\) & 18.14 \(\pm\) 6.32\({}^{\text{\tiny{CC}}}\) & 3.12 \(\pm\) 0.32\({}^{\text{\tiny{AC}}}\) \\  & Grape seed & 12.23 \(\pm\) 2.19\({}^{\text{\tiny{BB}}}\) & 22.51 \(\pm\) 3.52\({}^{\text{\tiny{GB}}}\) & 21.86 \(\pm\) 5.51\({}^{\text{\tiny{GB}}}\) & 2.47 \(\pm\) 0.31\({}^{\text{\tiny{GB}}}\) \\ \hline \multirow{3}{*}{TBARs} & Coconut & 0 \(\pm\) 0\({}^{\text{\tiny{AA}}}\) & 0 \(\pm\) 0\({}^{\text{\tiny{AA}}}\) & 0 \(\pm\) 0\({}^{\text{\tiny{AA}}}\) & 2.19 \(\pm\) 0.10 \({}^{\text{\tiny{GB}}}\) \\  & Rapeseed & 6.37 \(\pm\) 0.87\({}^{\text{\tiny{BC}}}\) & 5.51 \(\pm\) 0.72\({}^{\text{\tiny{BC}}}\) & 1.96 \(\pm\) 0.10\({}^{\text{\tiny{GB}}}\) & 7.57 \(\pm\) 0.85\({}^{\text{\tiny{CC}}}\) \\  & Grape seed & 1.11 \(\pm\) 0.22\({}^{\text{\tiny{BB}}}\) & 3.69 \(\pm\) 0.67\({}^{\text{\tiny{BB}}}\) & 1.09 \(\pm\) 0.11\({}^{\text{\tiny{AC}}}\) & 3.92 \(\pm\) 0.23\({}^{\text{\tiny{BB}}}\) \\ \hline \hline \end{tabular}  
* Small letters in the rows indicate statistically significant differences (\(p\) \(<\) 0.05) among treatments for the same oil (Bonferroni post hoc test). Different capital letters in the columns (within each parameter) represent statistically significant differences (\(p\) \(<\) 0.05) among the three oils for each treatment (Bonferroni post hoc test). Mean values \(\pm\) standard deviations.  
\end{table} 
Table 2: PV values (meq Q\({}_{2}\)/kg of product) and TBARs values (mg MDA/kg of product) for the three oils: unheated (T0), after 10 and 20 days at 65 \({}^{\circ}\)C (T1 and T2, respectively) and after 90 min at 180 \({}^{\circ}\)C (T3). and rapeseed) during storage found a 30% decrease in oxidative stability in all oils after 12 months of storage [19]. The most widely used method for the determination of malondialdehydedehyde, which is considered the most representative marker of the secondary products of lipid oxidation, is the TBARs method [3].