# Comparative Analysis of Volatile Flavor Compounds in Seven Mustard Pastes via HS-SPME-GC-MS
## 2 Results and Discussion
### Identification of Volatiles in MPs
\begin{table}
\begin{tabular}{l c c c c c c c c c c c} \hline \multirow{2}{*}{**Compounds**} & \multicolumn{8}{c}{**Concentration (ug/g)**} & \multicolumn{8}{c}{**Matching Degree**} & \multicolumn{1}{c}{**R/RI \(\ast\)**} & **Qualitative Method \(\ast\)** \\ \cline{2-11}  & **MP 1** & **MP 2** & **MP 3** & **MP 4** & **MP 5** & **MP 6** & **MP 7** & **Match** & **R.Match** & \\ \hline Carbon disulfide & + & + & + & + & + & + & + & 930 & 960 & 730/733 & MS, RI, S \\ Allyl chloride & + & + & + & + & + & + & + & 866 & 893 & 806/784 & MS, RI, S \\ Isothiazole & \(-\) & \(-\) & + & + & \(-\) & \(-\) & \(-\) & 899 & 908 & 121/81 & MS \\ N-Allylacetamide & \(-\) & \(-\) & \(-\) & + & \(-\) & \(-\) & 831 & 852 & 1761/N & MS \\ Hexanoic acid & \(-\) & \(+\) & \(-\) & + & \(-\) & \(-\) & + & 949 & 952 & 180/1850 & MS, RI, S \\ \(\cdot\)3-Methylphenol & \(-\) & \(-\) & \(+\) & \(-\) & \(-\) & \(-\) & 936 & 945 & 2087/2085 & MS, RI, S \\ Dehydroacetic acid & \(-\) & \(-\) & \(-\) & \(-\) & \(-\) & \(+\) & \(-\) & 920 & 921 & 2274/N & MS \\ \hline \end{tabular}  
* \({}^{\ast}\)\({}^{\ast}\)\({}^{\ast}\): Detached \({}^{\ast}\)\({}^{\ast}\)\({}^{\ast}\)\({}^{\ast}\): Not detected: \({}^{\ast}\)RI- retention index on a DB-WAX column, RI \({}^{\ast}\) retention index in the literature ([[https://webbook.nist.gov/chemistry/](https://webbook.nist.gov/chemistry/)]([https://webbook.nist.gov/chemistry/](https://webbook.nist.gov/chemistry/)) (accessed on 20 March 2023); \({}^{\ast}\)\({}^{\ast}\)\({}^{\ast}\)N\({}^{\ast}\): retention index was not found in the literature; \({}^{\ast}\)MS\({}^{\ast}\) meets identified by mass spectrometry; \({}^{\ast}\)RI\({}^{\ast}\) means identified by retention index, and \({}^{\ast}\)S\({}^{\ast}\) means identified by the standard compounds.  
\end{table} 
Table 1: _Cont._Another compound found among the seven MPs, 3-butenyl isothiocyanate, has a mustard-like pungent aroma and was detected in MP1, MP2, MP4, and MP6 [18]. Phenethyl isothiamate had a fresh radish-like pungent note and was identified in all samples; it was noteworthy that the lowest variety of raw materials was used in MP 7, and only AITC and phenethyl isothiamate were identified. In addition, carbon disulfide should be produced by the degradation of AITC [16]. Allyl chloride was identified in all seven MPs, and its source might be associated with the use of AITC. Allyl chloride and sodium thiocyanate were used as raw materials in the synthesis of AITC. At present, both Chinese mandatory standard GB 29980-2013 [19] and the quality specifications of the Joint Expert Committee on Food Additives (JECFA) were used to determine the composition of the AITC and the composition of the AITC. \begin{table}
\begin{tabular}{l l l} \hline \hline
**Sample** & **Common Raw Materials** & **Flavor Material** & **Other Raw Materials** \\ \hline MP 1 & & Mustard oil & Lactose, refined cane sugar, citric acid, \\  & & & corn starch, xanthan gum, turmeric \\ MP 2 & & Horseradish, edible spice & Lactose, citric acid, glyceryl \\  & & monostearate, xanthan gum, turmeric \\ MP 3 & Water; edible oil; sorbitol; & Lactose, citric acid, glyceryl \\  & & & monostearate, avicel, xanthan \\  & & blue (pigment) & gum, turmeric \\ MP 4 & & Wasabi, fresh wasabi & Glucose, citric acid \\  & & & Lactose, ansemi, xanthan gum, sodium \\ MP 5 & & Horseradish, spice, flavoring essence & diacetate, turmeric \\ MP 6 & & Horseradish powder & Citric acid, edible starch \\ MP 7 & & Horseradish powder & No other ingredient \\ \hline \hline \end{tabular}
\end{table} 
Table 2: The materials used in the seven MP samples. Figure 2: The upset plot of the seven MPs. Yellow bars represent the number of volatile compounds identified in the seven MPs. Gray dots represent absence, while black dots represent the presence of the unique compounds. If more than one sample contains the same unique compound, they are connected with lines. The number of unique compounds presented individually or jointly is represented by green bars.