## 3 Results and Discussion
### Thermodynamic Study
\begin{table}
\begin{tabular}{c c c c} \hline \hline
**Samples** & \begin{tabular}{c} \(E_{a}\) \\ **(kJ/mol)** \\ \end{tabular} & \begin{tabular}{c} \(\Delta H\) \\ **(kJ/mol)** \\ \end{tabular} & \
\begin{tabular}{c} \(\Delta S\) \\ **(J/mol)** \\ \end{tabular} &
\begin{tabular}{c} \(\Delta G\) 90 \({}^{\circ}\)C \\ **(kJ/mol)** \\ \end{tabular} \\ \hline B0 & 77.53 \(\pm\) 2.65 \({}^{\text{a}}\) & 74.43 \(\pm\) 2.65 \({}^{\text{a}}\) & \(-\)127.36 \(\pm\) 7.20 \({}^{\text{a}}\) & 120.68 \(\pm\) 1.04 \({}^{\text{a}}\) \\ B5 & 78.22 \(\pm\) 0.96 \({}^{\text{a}}\) & 75.12 \(\pm\) 0.96 \({}^{\text{a}}\) & \(-\)122.45 \(\pm\) 2.73 \({}^{\text{a}}\) & 119.58 \(\pm\) 1.95 \({}^{\text{a}}\) \\ B10 & 56.99 \(\pm\) 1.52 \({}^{\text{b}}\) & 53.89 \(\pm\) 1.52 \({}^{\text{b}}\) & \(-\)177.36 \(\pm\) 3.84 \({}^{\text{b}}\) & 118.30 \(\pm\) 2.91 \({}^{\text{a}}\) \\ \hline \hline \end{tabular} Values with different superscript letters are statistically different for \(p<0.05\). B0: control breadsticks; B5: breadsticks fortified with 5% of GP; B10: breadsticks fortified with 10% of GP.  
\end{table} 
Table 3: Energy of activation (\(E_{a}\)), enthalpy of activation (\(\Delta H\)), entropy of activation (\(\Delta S\)), and determination of Gibbs free energy at 90 \({}^{\circ}\)C (\(\Delta G\) 90 \({}^{\circ}\)C) of control and fortified samples (B0, B5, and B10). In fortified samples, ABTS increased proportionally to the addition of GPP, independently from the day of storage (panel b, Figure 1). From T0 to T5, there is no evident trend, but antioxidant capacity within T5 was statistically lower compared to T0, for all samples. This indicates that breadsticks' oxidation started, lowering antioxidant activities, and these results agreed with OXITEST predicted shelf-life. FRAP values were statistically different between samples (panel c, Figure 1). For example, B5 and B10 had statistically higher antioxidant capacity at the beginning of the study (T0); however, a reduction occurred in 15 days (T1). At the same time, the reduction of FRAP antioxidant capacity was slightly lower for B0. In the current study, the method for extracting the antioxidant molecules is optimized for phenols, while other components could play a role in the different antioxidant activities. For example, Maillard reaction products generated during the thermal processing could be considered responsible for enhancing the antioxidant activities, as mentioned by [PERSON] et al. (2012) [PERSON] et al. (2012). Therefore, the two antioxidant activities tests can differently quantify these substances. Apparently, in the current study, GPP polyphenols did not exert antioxidant activities against breadsticks lipid oxidations and did not prolong the shelf-life of products. This could be explained considering different factors. At first, the addition of GPP could have increased the polyunsaturated fatty acid (PUFA) concentration [32; 33] in breadstick, and this could result in an earlier oxidation onset [PERSON] et al. (2012). Moreover, Cabernet cultivar grape  
Figure 1: To different letters correspond different means within the same graph (\(p\) < 0.05). Gray line stands for B10, orange line for B5, and blue line for B0; (**a**) TPC; (**b**) ABTS; (**c**) FRAP. GAE: gallic acid equivalent; TE: Trolox equivalent; DM: dry matter. pomace is described to have about 9 g/100 g DM (Dry Matter) of fat, and more than 50% are PUFA [35]. Under this point of view, the dramatic decrease in antioxidant power of GP measured by FRAP could suggest the quick consumption of antioxidant molecules present in GP that are detectable only at T0. Finally, a pro-oxidant action of GP component should be evaluated [36].