## Results and Discussion
### Diversity of volatiles isolated by headspace solid-phase microextraction (HS-SPME)
#### Diversity of volatiles isolated by ultrasonic solvent extraction (USE)
\begin{table}
\begin{tabular}{l l c c c c c} \hline \hline \multirow{2}{*}{**No.**} & \multirow{2}{*}{**Compound**} & \multirow{2}{*}{**RI**} & \multicolumn{4}{c}{**Area percentage (\%)**} \\ \cline{3-6}  & & \multicolumn{2}{c}{**Min.**} & \multicolumn{2}{c}{**Max.**} & \multicolumn{2}{c}{**Av.**} & \multicolumn{2}{c}{**SD.**} \\ \hline
1. & 4-Methyloctane\({}^{*}\) & \(\diamond\) 900 & 0.1 & 0.2 & 0.13 & 0.06 \\
2. & Ethylbenzene & \(\diamond\) 900 & 0.3 & 0.4 & 0.33 & 0.06 \\
3. & 1,4-Dimethylbenzene (\(p\)-Xylene) & \(\diamond\) 900 & 1.3 & 2.0 & 1.60 & 0.36 \\
4. & Ethenylbenzene & \(\diamond\) 900 & 0.0 & 0.2 & 0.10 & 0.10 \\
5. & 1,3-Dimethylbenzene (\(m\)-Xylene) & \(\diamond\) 900 & 0.2 & 0.5 & 0.33 & 0.15 \\
6. & Methoxybenzene\({}^{\rm a}\) (Anisol) & 920 & 0.3 & 0.5 & 0.37 & 0.11 \\
7. & Benzaldehyde\({}^{\rm a}\) & 965 & 0.0 & 0.1 & 0.07 & 0.06 \\
8. & 2,3-Dihydro-3,5-dihydroxy-6-methyl-4H-pyran-4-one & 980 & 0.4 & 0.6 & 0.50 & 0.10 \\
9. & 2-Ethylfuran & 982 & 0.7 & 2.3 & 1.57 & 0.70 \\
10. & Benzyl alcohol\({}^{\rm a}\) & 1037 & 0.5 & 1.3 & 0.80 & 0.44 \\
11. & Phenylacetaldehyde\({}^{\rm a}\) & 1048 & 0.0 & 0.1 & 0.07 & 0.06 \\
12. & _trans_-Linalool oxide (furan type) & 1076 & 0.3 & 0.7 & 0.53 & 0.21 \\
13. & 4,5-Dimethyl-2-formylfuran & 1078 & 0.2 & 0.9 & 0.47 & 0.38 \\
14. & 1-(2-Furanyl)-2-hydroxyethanone & 1084 & 0.4 & 1.0 & 0.63 & 0.32 \\
15. & _cis_-Linalool oxide (furan type) & 1091 & 0.0 & 0.1 & 0.06 & 0.05 \\
16. & Nonanal\({}^{\rm a}\) & 1105 & 0.0 & 0.2 & 0.10 & 0.10 \\
17. & 2-Phenylethanol\({}^{\rm a}\) & 1116 & 10.5 & 16.8 & 13.47 & 3.17 \\
18. & Benzoic acid\({}^{\rm a}\) & 1162 & 0.5 & 1.1 & 0.73 & 0.32 \\
19. & 4-Methylbenzyl alcohol\({}^{\rm a}\) & 1171 & 0.0 & 0.2 & 0.10 & 0.10 \\
20. & 3,7-Dimethylocta-1,5-dien-3,7-diol & 1191 & 0.0 & 0.4 & 0.20 & 0.20 \\
21. & 4-Vinylphenol\({}^{\rm a}\) & 1221 & 0.2 & 0.3 & 0.27 & 0.06 \\
22. & 5-Hydroxymethylfurfural\({}^{\rm a}\) & 1230 & 3.5 & 9.1 & 6.53 & 2.83 \\
23. & Phenylacetic acid\({}^{\rm a}\) & 1269 & 0.8 & 2.1 & 1.33 & 0.68 \\
24. & 1,4-di-_tert_-Butylbenzene & 1257 & 0.0 & 0.4 & 0.20 & 0.20 \\
25. & Nonanoic acid\({}^{\rm a}\) & 1273 & 0.0 & 0.1 & 0.06 & 0.05 \\
26. & Benzene-1,4-diol & 1278 & 0.0 & 0.4 & 0.20 & 0.20 \\
27. & 1-Phenylethan-1,2-diol & 1304 & 0.2 & 0.7 & 0.50 & 0.26 \\
28. & 4-Vinyl-2-methoxyphenol & 1314 & 0.0 & 0.6 & 0.37 & 0.32 \\
29. & 1-Hydroxylinalool & 1365 & 0.0 & 1.8 & 1.03 & 0.93 \\
30. & Butoxyethoxyethyl acetate & 1371 & 0.0 & 0.2 & 0.07 & 0.11 \\
31. & 2-Phenylacetamide & 1393 & 3.2 & 7.4 & 5.50 & 2.13 \\
32. & 4-Hydroxy-3-methoxybenzaldehyde\({}^{\rm a}\) & 1397 & 0.0 & 0.2 & 0.10 & 0.10 \\
33. & 4-Hydroxybenzyl alcohol\({}^{\rm a}\) & 1426 & 0.8 & 2.0 & 1.40 & 0.60 \\
34. & 4-Methylobenzaldehyde\({}^{\rm a}\) & 1445 & 0.2 & 0.4 & 0.30 & 0.10 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: _A. frriticosa_ honey VOCs isolated by USE. Higher aliphatic alcohols and acids were the second most abundant class of VOCs of the USE extracts, particularly hexadecan-1-ol (2.5-6.6%), (Z)-octadec-9-en-1-ol (5.2-16.8%) and octadecan-1-ol (1.4-3.5%). Their presence was expected, due probably to their possible bees wax origin and they cannot be considered important for botanical origin determination, as indicated in a previous paper [16]. A low percentage of furan derivatives were identified, including 5-hydroxymethylfurfural