## 3 Results and Discussions
### Analysis of Volatiles of CLEO and Y-CNCs by SPME GC/MS  
The composition of the CLEO mixture essential oil is presented in Table 2. The most abundant constituents of VOCs in the CLEO mixture is cinnamaldehyde, representing almost a quarter of the total VOCs and iso-caryophyllene representing -15.5% of the volatiles, followed by \(\alpha\)-Pinene, \(\alpha\)-Phellandrene, and Eugenol. These VOCs originating either from lavender or cinnamon essential oil were reported also by other researchers [43; 44; 45; 46]. The 10 identified compounds represent approx. 70% of the total mixture components. All the VOCs were further traced in the Y films containing CNC but also in the control films. When comparing the total VOC area of Y-CNC with Yc it can be noticed a 4.61-5.89-fold higher volatile retention for all the films containing cellulose, thus demonstrating a better retention capacity in comparison with films with no cellulose (Table 3). The hierarchical clustering graph (Figure 5a) also shows a strong correlation between Y-CNC and CLEO with 93.15 similarity coefficients while all the Yc films are placed in an independent cluster with 98.0 similarity coefficients. Also, the dendrogram in Figure 5b shows correlations between Y1-CNC and Y3-CNC while in the case of control Y2c is closer from Y3c. The best retention capacity of VOCs displayed by the Y-CNC films was registered for Y3-CNC. However, when looking at each volatile component, there are just a few significant differences registered (\(p<0.05\)), for example when comparing Y1-CNC and Y3-CNC with Y2-CNC for cinnamaldehyde and eugenol. These compounds were also reported to present high antimicrobial activity [47; 48]. The heatmap (Figure 5a) compares the retention rates in relation with CLEO concentration and shows that for the highly volatile compounds eluted in the first half of the chromatogram the retention rate is relatively low for Y-CNC/CLEO and almost insignificant for Ycs given the red color of the heatmap. In the second half the retention rates tend to obtain better for Y-CNCs in comparison with control (Ycs) and the last two eluted components demonstrated the highest retention rates that varied from 47.99% in Y1-CNC to almost 68.00% in Y3-CNC in comparison with control samples where the retention was fair ranging from 24.41% in Y3c to 28.52 in Y2c. \begin{table}
\begin{tabular}{c c c c} \hline \hline
**RT** & **Compound** & **Top Five Ions** & **\% Total VOC** \\ \hline
18.06 & \(\alpha\)-Phellandrene & 91; 93; 77; 65; 51 & 3.83 \(\pm\) 0.11 \\
20.47 & Eucalyptus & 119;91; 134; 115; 77 & 0.21 \(\pm\) 0.01 \\
21.19 & \(\alpha\)-Pinene & 91; 93;77; 51; 121 & 4.79 \(\pm\) 0.52 \\
30.27 & \(\alpha\)-Cubebene & 105; 161; 119; 91; 93 & 0.39 \(\pm\) 0.08 \\
33.61 & 3-Carene & 91; 93; 81; 79; 77 & 13.52 \(\pm\) 8.62 \\
36.54 & Isocaryophilene & 91; 133; 120; 77; 105 & 15.5 \(\pm\) 4.35 \\
40.13 & Carryophyllene & 93; 133; 91; 47; 79 & 3.51 \(\pm\) 0.89 \\
41.82 & Camphene & 93; 121; 79; 91; 39 & 0.83 \(\pm\) 0.09 \\
57.14 & Cinnamaldehyde & 131; 103; 77; 132; 51 & 24.74 \(\pm\) 7.87 \\
61.36 & Cinnamyl alcohol acetate & 115; 133; 91; 176; 77 & 0.62 \(\pm\) 0.25 \\
61.82 & Eugenol & 164; 149; 131; 103; 91 & 2.47 \(\pm\) 0.62 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: GC/MS SPME fingerprint of CLEO mixture indicating the % of the 10 most abundant VOCs tentatively identified compounds.