## 3 Results
### Characterization of Volatile Signature in Onions
\begin{table}
\begin{tabular}{c c c c c c c c c c c c} \hline \hline
**Peak n\({}^{*}\)** & **RT (min)\({}^{*}\)** & **KI calc b\({}^{\text{b}}\)** & **KI LL c\({}^{*}\)** & **Chemical Groups/VOMs** & **Similarity** & \multicolumn{4}{c}{**GC Peak Area \(\times\) 10\({}^{\text{b}}\) (USD)**} \\ \cline{5-10}  & & & & & **(\%)** & & **Canigo** & **Santa Cruz** & **Ribeira Brava** & **Porto Moniz** \\ \hline  & & & & & & & & & & & \\ \cline{5-10}
2 & 4.56 & 649 & 635 & Methanediol & 90 & - & - & 14.66 & (19) & - & \\
3 & 4.82 & 661 & 660 & Carbon disulfide & 83 & 129.23 & (17) & 99.71 & (15) & - & 107.84 & (9) \\
5 & 5.82 & 802 & 770 & 1-Prospinethol & 95 & 34.91 & (17) & 20.56 & (12) & 69.28 & (17) & 155.06 & (17) \\
7 & 7.73 & 954 & 961 & Thiophene & 93 & 196.25 & (4) & - & - & - & - \\
8 & 12.93 & 1068 & 1008 & Dimethyl disulfide & 94 & 18.93 & (13) & - & - & 4.07 & (7) \\
11 & 16.40 & 1134 & 1127 & 3-Methyl-thiophene & 86 & - & 4.41 & (7) & - & 4.07 & (7) \\
12 & 16.95 & 1143 & 1150 & Thiophene & 86 & - & 13.03 & (17) & - & - & - \\
16 & 18.75 & 1173 & 1191 & 1-Methyl-thiophenethetheth & 94 & 58.51 & (16) & 70.04 & (19) & 92.79 & (9) & 109.63 & (11) \\
17 & 19.85 & 1190 & 1215 & Methyl2-propenyl disulfide & 64 & - & 12.07 & (14) & - & 80.11 & (14) \\
19 & 21.24 & 1213 & 1221 & Methoxymethylbutanediol & 91 & 25.45 & (16) & - & 137.96 & (17) & 152.55 & (19) \\
20 & 22.63 & 1235 & 1224 & Methyl propoly disulfide & 87 & 203.82 & (12) & 1280.73 & (14) & 1482.78 & (9) & 184.03 & (5) \\
21 & 23.20 & 1244 & 1228 & Methyl isothiamate & 82 & 201.68 & (10) & 83.93 & (9) & 380.48 & (19) & 48.61 & (17) \\
23 & 24.64 & 1265 & 1253 & 2,4-Dimethyl-thiophene & 74 & 228.34 & (16) & 13.99 & (14) & - & 313.06 & (5) \\
24 & 25.10 & 1272 & 1273 & Hexennethol & 64 & - & 222.73 & (10) & - & - & 115.76 & (15) \\
26 & 30.84 & 1358 & 1370 & Dippoly disulfide & 91 & 1528.80 & (18) & 2364.77 & (13) & 14.144.44 & (7) & 11201.60 & (15) \\
27 & 31.10 & 1362 & 1364 & Dimethyl disulfide & 97 & 812.81 & (13) & - & 338.43 & (16) & - & \\
31 & 35.09 & 1423 & 1428 & 1-Propenypropyl disulfide isomer & 73 & 4.35 & (11) & - & - & - & - \\
32 & 36.05 & 1439 & 1429 & Thermythbiol & 91 & 29.44 & (12) & - & 75.95 & (18) & - \\
33 & 36.31 & 1444 & 1438 & 2-Penrithiophene & 74 & - & 27.18 & (5) & 215.22 & (1) & 34.47 & (18) \\
36 & 36.81 & 1452 & 1458 & Methonal & 79 & - & - & - & 291.57 & (11) \\
39 & 38.28 & 1475 & 1476 & 2-Methyl-13-thionine & 78 & - & - & - & - & 480.55 & (10) \\
40 & 38.71 & 1482 & 1506 & Methyldihydropropheno & 87 & - & - & - & - & 14.10 & (9) \\
42 & 39.35 & 1492 & 1516 & Methylpropyl trisulfide & 78 & 35.29 & (7) & 45.86 & (17) & - & 313.73 & (10) \\
47 & 41.98 & 1535 & 1520 & Methylidiidiidiidiidiidiidi & 78 & - & 95.76 & (16) & - & 155.88 & (15) \\
52 & 46.52 & 1066 & 1606 & Sulutrol & 78 & 4.14 & (13) & - & - & - & - & - \\
53 & 48.90 & 1646 & 1622 & Primermethylmethyl & 95 & 3110.10 & (17) & 768.23 & (10) & 3310.32 & (8) & 2998.66 & (19) \\
57 & 51.35 & 1686 & 1667 & Methyl/(methyl/imidimidimid) & 80 & 74.19 & (11) & - & - & 304.68 & (5) \\
59 & 52.50 & 1704 & 1700 & 3-(Acetylthio-2 methylfuran & 82 & 2639.08 & (16) & - & 354.53 & (9) & 44.83 & (9) \\
60 & 53.19 & 1716 & 1723 & Methanol & 89 & - & - & - & 946.48 & (19) \\
62 & 54.30 & 1734 & 1738 & Thiophene & 82 & - & 28.46 & (16) & - & 225.70 & (13) \\
63 & 54.46 & 1737 & - & 3,5-Diethyl-12,4-trithionine isomer & 78 & - & 521.55 & (10) & - & - & 902.44 & (9) \\
64 & 54.71 & 1741 & 1759 & 3-Methyl-thiophenethol & 78 & 133.36 & (18) & - & - & - & 902.24 & (9) \\
67 & 58.41 & 1798 & 1785 & Acetylthiophene & 75 & 33.52 & (10) & 191.17 & (15) & 173.31 & (12) & 295.88 & (18) \\
69 & 62.96 & 1896 & 1896 & 5-(Methylthio-1)-pentennitrile & 72 & 24.88 & (12) & 87.04 & (5) & - & - & - \\
75 & 70.43 & 2010 & 1998 & Methyl methanoisoisulfonate & 75 & 19.28 & (14) & 65.46 & (13) & 44.65 & (10) & - & - \\
76 & 73.52 & 2029 & 2038 & 5-Methoxy-thiazole & 72 & 40.10 & (13) & 314.49 & (16) & 124.92 & (16) & 82.21 & (11) \\ \hline \hline \end{tabular}
\end{table}