## 3 Results
### Antioxidant Capacity Determination  
The antioxidant capacity of pericarp chestnut samples, determined by DPPH, ABTS, FRAP and CV tests, are reported in Table 3 together with the chestnut extract concentrations necessary to achieve a 50% radical DPPH or ABTS inhibition (EC\({}_{50}\)).  
The three different spectrophotometric tests seem to indicate that the antioxidant activity of MURG, LOCG, COEV and ILDP accessions was not particularly influenced by the solvent temperature, albeit with the exception of the DPPH tests on MURG and COEV. Differently, the antioxidant activity of the MARRV extract at 95 \({}^{\circ}\)C was definitely higher than those at 20 \({}^{\circ}\)C. The results of the electrochemical tests slightly differed from those of the other assays, but this was expected since the radicals (DPPH* and ABTS*+) react with almost all the compounds present in the extracts able of giving up electrons, while the AUC values refer only to compounds that release electrons at an applied potential (E\({}_{\rm app}\)) of +0.5 V; AUC was higher at 20 \({}^{\circ}\)C in MURG, at 95 \({}^{\circ}\)C in LOCG and MARRV, and not statistically different in ILDP and COEV. The difference among the results obtained with different methods will be discussed, with appropriate bibliographical references, in the \"Discussion\" chapter.  
EC\({}_{50}\) values ranged from 0.029 and 0.058 mg mL\({}^{-1}\) when calculated with DPPH, and from 0.026 and 0.046 when calculated with ABTS method. Slight statistically significant differences in EC\({}_{50}\) were observed for MURG only when determined with DPPH, while a marked difference was observed between hot and cold extracts of MARRV according to both methods.  
The relationship among the parameters shown in Table 2 and the antioxidant capacities displayed in Table 3 were determined by Pearson correlation analysis and reported in Tables S1 and S2 in Supplementary Materials. For cold extracts: TP was highly correlated with DPPH (R\({}^{2}\) = 0.979) and ABTS (R\({}^{2}\) = 0.971) values but moderately with FRAP (R\({}^{2}\) = 0.787); the PA was highly correlated with DPPH (R\({}^{2}\) = 0.904) and ABTS (R\({}^{2}\) = 0.933); TF values were in good correlation with DPPH (R\({}^{2}\) = 0.807) and ABTS (R\({}^{2}\) = 0.831) and moderately with FRAP (R\({}^{2}\) = 0.714). DPPH and ABTS spectrophotometric assays were highly correlated with each other and in good correlation with FRAP; and FRAP was in good correlation with AUC\({}_{0.5}\) and AUC\({}_{0.8}\), while DPPH and ABTS were not. For hot extracts: the correlation coefficients between TP and spectrophotometric tests for antioxidant activity were lower than for cold extracts (R\({}^{2}\) = 0.758 vs. DPPH, 0.733 vs. ABTS and 0.743 vs. FRAP); and TF and PA were highly correlated with DPPH and ABTS but not correlated with FRAP. DPPH and ABTS values were highly correlated with each other (R\({}^{2}\) = 0.995) but not with FRAP; also in this case, as for the cold extracts, FRAP resulted in good correlation with AUC\({}_{0.5}\) and in moderate correlation with AUC\({}_{0.8}\). Finally, all the EC\({}_{50}\) values were negatively correlated to the studied parameters, thus indicating that an increase in bioactive compounds corresponded to a lower extract concentration necessary to achieve 50% of DPPH or ABTS radicals' inhibition.