## 3 Results and Discussion
### Non-Volatile Compounds (Glucosinolates)
#### 3.2.1 'Salad' rocket  
'Salad' rocket contained the highest dry weight concentrations of GSLs (111.1 \(\pm\) 14.6 \(\mu\)mol g\({}^{-1}\) dw). This was predominantly due to high amounts of DMB (78.9 \(\pm\) 8.4 \(\mu\)mol g\({}^{-1}\) dw). Other GSLs of note included GSV (6.6 \(\pm\) 2.4 \(\mu\)mol g\({}^{-1}\) dw), GRM (7.6 \(\pm\) 1.2 \(\mu\)mol g\({}^{-1}\) dw), and DGTB (4.6 \(\pm\) 1.1 \(\mu\)mol g\({}^{-1}\) dw), which are unique to the genera _Eruca_ and _Diplotaxis_. Other routinely reported GSLs for this species were GRA (1.8 \(\pm\) 0.5 \(\mu\)mol g\({}^{-1}\) dw) and NGB (2.7 \(\pm\) 0.4 \(\mu\)mol g\({}^{-1}\) dw). Interestingly, several other GSLs that have not been, or are rarely reported for the species, were also detected; some in relatively high concentrations: GIB (<0.1 \(\pm\)0.1 \(\mu\)mol \begin{table}
\begin{tabular}{l c c c c} \hline \hline \multirow{2}{*}{**Glucosinolate 1**} & \multirow{2}{*}{**Abbreviation**} & \multicolumn{3}{c}{**Concentration 2****} \\ \cline{3-5}  & & **Salad** & **Rocket** & **Wasabi** & **Watercress** \\ \hline glucoiberin & GIB & 0.007 \(\pm\) 0.001 & 0.003 \(\pm\) & \(<\)0.001 & nd \\ pentyl GSL 3  & PEN & 4.915 \(\pm\) 1.633 & nd & nd \\ progoitrin & PRO & 0.074 \(\pm\) 0.067 & 0.001 \(\pm\) & \(<\)0.001 & nd \\ sinigrin & SIN & 0.002 \(\pm\) 0.001 & 11.121 \(\pm\) 0.247 & 0.001 \(\pm\) \(<\)0.001 \\ isobutyl GSL 4  & ISO & nd & 3.382 \(\pm\) 0.762 & nd \\ glucoerphaninin & GRA & 1.761 \(\pm\) 0.508 & 0.001 \(\pm\) & \(<\)0.001 & 0.006 \(\pm\) \(<\)0.001 \\ glucorucolamine & GRM & 7.571 \(\pm\) 1.208 & nd & nd \\ glucoalysissin & GAL & 0.215 \(\pm\) 0.044 & 2.123 \(\pm\) 0.477 & 0.470 \(\pm\) 0.026 \\ glucoputranjivin 5  & GPJ & 0.058 \(\pm\) 0.024 & 2.289 \(\pm\) 0.515 & nd \\ gluconapin & GNP & 0.001 \(\pm\) 0.001 & 0.010 \(\pm\) 0.001 & nd \\ diglucothiobein & DGTB & 4.622 \(\pm\) 1.144 & nd & nd \\ glucoberteorin & GBT & 0.412 \(\pm\) 0.086 & nd & nd \\
4-hydroxyglucobrassicin & 4 HGB & 0.012 \(\pm\) 0.002 & 0.062 \(\pm\) 0.002 & 0.006 \(\pm\) \(<\)0.001 \\ glucocochlearin & GCL & nd & 2.184 \(\pm\) 0.166 & nd \\ glucosativin & GSV & 6.639 \(\pm\) 2.402 & nd & nd \\
7-(methylsulfinyl)heptyl & 7 MSH & nd & 4.55 \(\pm\) 0.393 & 21.472 \(\pm\) 1.219 \\ glcubrassicanapin & GBN & nd & 0.146 \(\pm\) 0.005 & nd \\ dimeric 4-mercaptoethanolbutyl & DMB & 78.861 \(\pm\) 8.384 & nd & nd \\ glucobarbarin & GBB & nd & nd & 0.730 \(\pm\) 0.037 \\ glucotropaeolin & GTP & 0.027 \(\pm\) 0.002 & 0.001 \(\pm\) & \(<\)0.001 & 0.001 \(\pm\) \(<\)0.001 \\ glucoerucin & GER & 0.733 \(\pm\) 0.088 & nd & nd \\ glucobrassicin & GBC & 0.027 \(\pm\) 0.008 & 0.001 \(\pm\) & \(<\)0.001 & 0.118 \(\pm\) 0.006 \\
4-methoxyglucobrassicin & 4 MGB & 0.366 \(\pm\) 0.113 & nd & 2.001 \(\pm\) 0.104 \\ glucoasturtin & GNT & 0.001 \(\pm\) & 0.001 & nd & 1.514 \(\pm\) 0.040 \\ neoglucobrassicin & NGB & 2.682 \(\pm\) 0.433 & 1.525 \(\pm\) 0.229 & 1.596 \(\pm\) 0.037 \\
4-methylpentyl GSL & 4 MP & 1.293 \(\pm\) 0.836 & nd & nd \\ hexy GSL & HEX & 0.225 \(\pm\) 0.071 & nd & 0.434 \(\pm\) 0.031 \\
7-(methylthio)heptyl GSL & 7 MTH & nd & 0.132 \(\pm\) 0.035 & 2.663 \(\pm\) 0.104 \\ butyl GSL 6  & BUT & 0.301 \(\pm\) 0.081 & nd & 0.606 \(\pm\) 0.359 \\
**Total** & & 111.098 \(\pm\) & 27.532 \(\pm\) 2.831 & 31.645 \(\pm\) 1.353 \\  & & 14.633 & & \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Glucosinolate concentrations of ’salad’ rocket, wasabi, and watercress determined by UPLC-MS/MS. g\({}^{-1}\) dw), PEN (4.9 \(\pm\) 1.6 \(\upmu\)mol g\({}^{-1}\) dw), GPJ (<0.1 \(\pm\) \(<\)0.1 \(\upmu\)mol g\({}^{-1}\) dw), GBT (0.4 \(\pm\) \(<\)0.1 \(\upmu\)mol g\({}^{-1}\) dw), GTP (<0.1 \(\pm\) \(<\)0.1 \(\upmu\)mol g\({}^{-1}\) dw), 4 MP (1.3 \(\pm\) 0.8 \(\upmu\)mol g\({}^{-1}\) dw), HEX (0.2 \(\pm\) <0.1 \(\upmu\)mol g\({}^{-1}\) dw), and BUT (0.3 \(\pm\) \(<\)0.1 \(\upmu\)mol g\({}^{-1}\) dw). Of note is the high abundance of PEN (_m/z_ 388). It seems unlikely that a GSL of such relatively high concentration has gone undetected in previous analyses.