## 3 Results and Discussion
### Effect of Storage on Fatty Acids and Volatile Composition of Negroamaro GPF
\begin{table}
\begin{tabular}{c c c c c c c c c c c c c} \hline \hline  & \multicolumn{10}{c}{**Time Storage (Months)**} \\ \hline  & **0** & **1** & **2** & **3** & **4** & **5** & **6** & **0** & **1** & **2** & **3** & **4** & **5** & **6** \\ \hline \multicolumn{10}{c}{**\% of Total Fatty Acids Identified**} \\ \hline
**Fatty Acids** & \multicolumn{10}{c}{**4 \({}^{\circ}\)C**} \\ \hline Palmitic acid & 11.55 & 12.46 & 12.72 & 12.81 & 13.09 & 14.37 & 14.72 \({}^{\ast}\) & 11.55 & 12.71 & 12.57 & 12.77 & 13.10 & 13.66 & 15.28 \\ C16:0 & & & & & & & & & & & & \\ Palmitic acid & 0.71 & 1.01 & 0.95 & 0.96 & 0.78 & 0.76 & 0.91 \({}^{\ast}\) & 0.71 & 0.95 \({}^{\ast}\) & 0.99 \({}^{\ast}\) & 0.92 \({}^{\ast}\) & 1.20 \({}^{\ast}\) & 0.93 \({}^{\ast}\) & 1.07 \({}^{\ast}\) \\ Stearic acid & 6.81 & 7.43 & 7.04 & 7.22 & 7.19 & 9.49 \({}^{\ast}\) & 9.52 \({}^{\ast}\) & 6.81 & 7.23 \({}^{\ast}\) & 7.03 \({}^{\ast}\) & 7.94 \({}^{\ast}\) & 7.63 \({}^{\ast}\) & 9.12 \({}^{\ast}\) & 9.96 \({}^{\ast}\) \\ Oleic acid & 23.57 & 23.64 & 23.09 & 23.50 & 23.76 & 21.50 & 21.09 & 23.57 & 23.17 & 23.31 & 23.82 & 23.67 & 22.02 & 20.97 \\ Linoleic acid & 53.85 & 52.39 & 53.40 & 52.88 & 52.35 & 51.27 & 51.16 & 53.85 & 52.96 & 53.20 & 51.58 & 51.58 & 51.69 & 50.17 \\ Linolenic acid & 2.97 & 2.47 & 2.29 & 2.14 \({}^{\ast}\) & 2.12 \({}^{\ast}\) & 1.99 \({}^{\ast}\) & 2.08 \({}^{\ast}\) & 2.97 & 2.44 & 2.40 & 2.26 \({}^{\ast}\) & 2.20 \({}^{\ast}\) & 2.06 \({}^{\ast}\) & 2.00 \({}^{\ast}\) \\ Crackilic acid & 0.54 & 0.60 & 0.51 & 0.49 & 0.71 \({}^{\ast}\) & 0.62 \({}^{\ast}\) & 0.52 & 0.54 & 0.54 & 0.50 & 0.71 \({}^{\ast}\) & 0.62 & 0.52 & 0.55 \\
**SFA** & **18.90** & **20.49** & **20.27** & **20.52** & **20.99** & **24.48 \({}^{\ast}\)** & **24.66 \({}^{\ast}\)** & **18.90** & **20.48** & **20.10** & **21.42 \({}^{\ast}\)** & **21.35 \({}^{\ast}\)** & **23.30 \({}^{\ast}\)** & **25.79 \({}^{\ast}\)** \\
**MUFA** & **24.28** & **24.65** & **24.04** & **24.46** & **24.54** & **22.36** & **22.10** & **24.28** & **24.12** & **24.30** & **24.74** & **24.87** & **22.95** & **22.04** \\
**PUFA** & **56.82** & **54.86** & **55.69** & **55.02** & **54.47** & **53.16** & **53.24** & **56.82** & **55.40** & **55.60** & **53.84** & **53.78** & **53.75** & **52.17** \\ \hline \multicolumn{10}{c}{Standard deviation is less than 10\%. \({}^{\ast}\)\({}^{\ast}\)\({}^{\ast}\) indicates statistically significant differences (\(p<0.05\)) between each treatment after T1, T2, T3, T4, T5 and T6 time (months) versus initial storage time (T0) as determined by the two sample-\(t\)-test and the Mann-Whitney U Test.} \\ \end{tabular}
\end{table} 
Table 2: Characterization and comparison of different fatty acids composition in GPF stored for six months at 4 and 25 \({}^{\circ}\)C in the dark. In all samples, esters, alcohols and aldehydes were the main groups of compounds identified in GP. Esters ranged from 51.65% of the total peak area in T0 sample to 63.38 and 77.40% in T6_4 \({}^{\circ}\)C and T6_25 \({}^{\circ}\)C, respectively. Alcohols ranged from 31.49% in T0 to 31.38 and 36.88% in T6_4 \({}^{\circ}\)C and T6_25 \({}^{\circ}\)C, respectively. Ethyl esters of fatty acids with a linear chain from 6 to 18 carbon atoms, are the molecules with the highest concentration detectable in all samples. The volatile fraction of Negroamaro grapes is also characterized by ethyl esters in free form whose content depends from ethanolysis of acetyl-CoA during fatty acids synthesis or degradation [33]. Among acetate esters, ethyl acetate showed a decrease during storage from 4.24 mg/kg at T0 to 1.34 and 1.011 at T6_4 \({}^{\circ}\)C and T_25 \({}^{\circ}\)C, respectively. Lower concentrations of ethyl acetate in processed samples may be due to glucose reduction via Maillard reactions, or inactivation by microorganisms produced during storage [34]. The detection of esters in control sample and their increase during the storage suggests that the fruity odor of the initial raw material is well preserved.