## 4 Discussion  
The volatile chemical profile of dried hops and beers was described by SPME sampling technique followed by GC/MS analyses. The obtained results from hop analyses by the SPME technique showed that monoterene content exceeded that of the sesquiterpenes in all hop samples except for the PC sample where the ratio was reversed (Table 2). \(\beta\)-Myrcene was the predominant compound, and it is responsible for the pungent odor and aroma of hops [14]. In particular, the CCH sample was characterized by higher monoterenic content \begin{table}
\begin{tabular}{c c c} \hline \hline \multirow{2}{*}{**Beer**} & \multicolumn{2}{c}{**Total Polyphenols**} & \multicolumn{2}{c}{**Total Flavonoids**} \\  & **(mg GAE/100 mL Beer)** & **(mg QE/100 mL Beer)** \\ \hline IPA & 228.7 \(\pm\) 1.8 & 3.1 \(\pm\) 0.1 \\ LKO & 248.3 \(\pm\) 5.2 & 2.8 \(\pm\) 0.1 \\ ACD & 292.0 \(\pm\) 0.0 & 5.8 \(\pm\) 0.1 \\ \hline \end{tabular} IPA: “Ipagea” beer; LKO: “Lokomotive” beer; ACD: “Accademica” beer.  
\end{table} 
Table 6: Polypphenols and flavonoids of beer samples. \begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline  & & **STGe** & **HBKe** & **HLBe** & **CCHe** & **PCJe** & **PCe** & **TPe** \\ \hline \multirow{3}{*}{DPPH} & IC\({}_{50}\) * & 0.039 \(\pm\) 0.007 & 0.05 \(\pm\) 0.005 & 0.039 \(\pm\) 0.005 & 0.041 \(\pm\) 0.002 & 0.027 \(\pm\) 0.008 & 0.047 \(\pm\) 0.004 & 0.033 \(\pm\) 0.001 \\  & TEAC ** & 0.972 \(\pm\) 0.200 & 0.66 \(\pm\) 0.075 & 0.937 \(\pm\) 0.074 & 0.891 \(\pm\) 0.062 & 1.661 \(\pm\) 0.013 & 0.771 \(\pm\) 0.011 & 1.124 \(\pm\) 0.097 \\ \cline{2-9}  & IC\({}_{50}\) * & 0.041 \(\pm\) 0.004 & 0.071 \(\pm\) 0.014 & 0.015 \(\pm\) 0.002 & 0.134 \(\pm\) 0.009 & 0.037 \(\pm\) 0.004 & 0.024 \(\pm\) 0.005 & 0.023 \(\pm\) 0.005 \\ \cline{2-9}  & IC\({}_{50}\) * & 0.380 \(\pm\) 0.054 & 0.219 \(\pm\) 0.023 & 1.036 \(\pm\) 0.105 & 0.114 \(\pm\) 0.003 & 0.413 \(\pm\) 0.073 & 0.661 \(\pm\) 0.095 & 0.664 \(\pm\) 0.106 \\ \hline \multirow{6}{*}{ABTS} & \multicolumn{2}{c}{* mg/mL of hop samples; ** um of Trolox equivalent/ mg of dry hop samples. Values are expressed as means \(\pm\) SD. \(p\) < 0.05. STGe: “Stytrian Golding” hop extract; HBKe: “Hersbrucker” hop extract; HLBe: “Hallertau Blanc” hop extract; CCHe: “Cascade” hop extract; PCJe: “Pacifica Jade” hop extract; PCe: “Pacifica” hop extract; TPe: “Topa” hop extract.  
\end{table} 
Table 7: IC\({}_{50}\) and TEAC values of hop extract samples in DPPH and ABTS assays. (72.8%) of which \(\beta\)-myrrene was the most representative (71.4%). The high percentage of \(\beta\)-myrrene is due to the use of CRYO HOPS(r) technology (Yakima Chief Hops, LLC.-Yakima, WA, USA), an innovative hop production technique that allows the separation of lupulin from hop flower by cryogenic processing. The result of this technique is a product characterized by a more intense aromatic character with reduced astringency and vegetative material. In fact, the CCH hop sample was also found to be the poorest in both polyphenols and flavonoids (Table 5). The other detected monoterpenes from hops (SPME collection) were present in markedly lower percentages ranging between 0.1% and 1.2%. Humulene and \(\beta\)-caryophyllene were sesquiterpene compounds more relevant in all hop varieties. Their ratio is used as a marker and it is characteristic of each variety [15]. Moreover, several esters were identified in HLB, CCH, PCJ, PC and TP samples while they were missing in STG and HBK hops. This class of compounds is reported to be responsible for characteristic odors with floral and fruity tones [14]. Regarding headspace beer compositions described in Table 4, we found a low content of monoterpenes (\(\beta\)-myrrene and linalool in IPA and only \(\beta\)-myrrene in ACD); on the contrary, secondary alcohols, such as 2-methyl-1-butanol and 3-methyl-1-butanol detected in the three beer samples, contributed mostly to the total amount of alcohols with percentage values ranging from 1.2% to 2.5% and from 2.5% to 9.6%, respectively. Several volatile compounds have been associated with specific flavors.