## 3 Results and Discussion
### Effect of Storage on Fatty Acids and Volatile Composition of Negroamaro GPF  
Analysis of the FA profile shows that polyunsaturated fatty acids (PUFA) accounted for approximately 57% of the total percentage of fatty acids identified, followed by mo-nounsaturated (MUFA, -24%) and saturated (SFA, -19%) acids (Table 2). Linoleic acid (C18:2n6) represented approximately 54% of the total fatty acids, followed by oleic (C18:1 n9, -24%), palmitic (C16:0, -11%) and stearic (C18:0, -7%) acid. During the storage period of six months, we observed a significant increase in SFA at 5 and 6 months (\(p<0.05\)) in GPF stored at 4 \({}^{\circ}\)C or 25 \({}^{\circ}\)C, compared to T0 (Table 2). However, neither MUFA nor PUFA content changed significantly across the time period analyzed, indicating excellent stability with regard to fatty acid oxidation. The presence of antioxidants such as polyphenols in GPF could play an important role in protecting unsaturated fatty acids from oxidation. Likewise, olive pomace by-products, that are characterized by a high content of  
Figure 1: Comparison of Total Phenols content in Negroamaro GPF during six months storage at 4 \({}^{\circ}\)C and 25 \({}^{\circ}\)C in the dark. Data represent mean values \(\pm\) standard deviation (\(n=3\)). \({}^{***}\) indicates a timepoint that was significantly different (\(p<0.05\)) relative to T0 as determined by the two sample-\(t\)-test and the Mann-Whitney U Test. Figure 2: Comparison of TEAC values (AA) in Negroamaro GPF during the six month storage period at 4 \({}^{\circ}\)C and 25 \({}^{\circ}\)C in the dark. Data represent mean values \(\pm\) standard deviation (\(n=3\)). phenolic compounds, have also been shown to increase oxidative stability and improving the quality and shelf life of food products [28]. Although the total lipid content in GPF is not very high, if GPF is subjected to storage conditions at temperature higher than 4 \({}^{\circ}\)C, enzymatic and non-enzymatic processes could contribute to lipid oxidation leading to rancidity. Therefore, we investigated whether changes in SFA, MUFA and PUFA content significant contribution to the oxidation stability of grape pomace flour. The stability of oleaginous component in the stored whole grape pomace flour containing seeds was assessed. Fatty acids (FAs) have a variable number of carbons and double bonds [29]. Generally, in foods containing a fatty component then, lipid oxidation is one of the main factors linked to oxidative rancidity, the loss of essential fatty acids, and the development of unpleasant flavor and smells in food ingredients. Polyphenols perform their antioxidant action by: (i) inactivating free radical, (ii) scavenging and neutralizing reactive oxygen species (ROS), (iii) enhancing the electron transfer, (iv) preventing the oxidation propagation phase and avoiding the formation of peroxides [30; 31]. We also characterized the volatile profile of Negroamaro GPF during six months of storage at different temperatures. In total, 30 volatile compounds were identified, quantified by triphasic fiber coupled GC-MS analysis and grouped according to the class of volatile (esters, alcohols, aldehydes, ketons, furrans and hydrocarbons). As shown in Figure 3 the differences between samples collected at T0 and after six months at 4-25 \({}^{\circ}\)C (T6_4 \({}^{\circ}\)C and T6_25 \({}^{\circ}\)C, respectively) appear to be quantitative rather than qualitative [32].