# Antimicrobial and Odour Qualities of Alkylpyrazines Occurring in Chocolate and Cocoa Products
## 2 Pyrazines in Chocolate and Cocoa
### Alkylpyrazines Detected in Cocoa and Chocolate  
Over the years, numerous scientists have studied the unique combination of the components inside cocoa and chocolate. In [PERSON] et al. 's research [17], the pyrazine-related molecules made up just over 40% of the cocoa powder essence. In total, 40 pyrazines which are present in cocoa and chocolate among the literature sources were identified. In Figure 1, their formulas are displayed. The \"odour fingerprint\" of each alkylpyrazine present in cocoa and chocolate is distinctive. We gathered information on their olfactory profiles from literature sources and from the Good Scents Company Information System (TGSCIS) [25], and we compiled the information in Table 1.  
Figure 1: Pyrazines, which were detected in samples of cocoa and chocolate. \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**CNN** & **Compound name** & **LSOP in Cooa** & **LSOP in DC** & **LSOP in MC** & **LS of Odour Description from Literature** & **Odaour Description from The Good** & **Scent Informational System** \\ \hline
1 & pyrazine & [17] & [13,20] & [12,13,17,28] & pumped, sweet, crude, halke, nutty, & pumped, sweet, corn, roasted, & hashler, bridge \\
2 & 2-methylpyrazine & [14,72,23] & [23,15,20,21,24] & [12,17,27,20,21,24,26] & methyl, hashler, chocolate, cocoa, & nutty, cocoa, roasted, chocolate, & nutty, cocoa, roasted, chocolate, \\  & 3 & 2-dimethylpyrazine & [14,47,22,27] & [23,15,20,21,24] & [12,17,27,20,21,24,26] & transited, open, sweet, nutty & neutral, open, earthty \\
3 & 2-dimethylpyrazine & [14,47,22,27] & [23,15,20,21,24] & [12,17,27,20,21,24,26] & transited, thin, green, coffee, & venture, expand, weather, coffee, \\  & 4 & 2-5-dimethylpyrazine & [14,17,29,23,27] & [13,15,20,21,24,26] & [12,13,17,17,20,21,24,26] & transited, open, roasted, hashler, & \\  & 5 & 2-dimethylpyrazine & [14,17,29,23,27] & [21] & [12,17,21,28] & protop, open, chocolate, chemical, & \\  & 5 & 2-6-dimethylpyrazine & [14,17,23] & [21] & [12,17,20,21,24,26] & transited, open, roasted, hashler, & \\  & 6 & trimethylpyrazine & [7,10,14,16,17,19,23,23] & [13,15,20,21,24,26] & [13] & [3,7,10,21,23,16,17,18] & transited, open, roasted, hashler, & \\  & 7 & 27,28,30] & [23,15,20,21,24,26] & [13] & [3,7,10,21,23,16,17,18] & transited, open, roasted, hashler, & \\  & 7 & & 27,28,30] & [23,15,20,21,24] & [10,12,13,19,21] & transited, open, roasted, hashler, & \\  & 8 & 2-ethylpyrazine & [14,17] & [13,20,21,24] & [13,17,20,21,26,29] & transited, open, roasted & \\  & 9 & 2-ethyl-3-methylpyrazine & [14,17,23] & [13,20,21] & [13,17,21,28] & hashler, roasted, raw potato, & \\  & 10 & 2-ethyl-3-methylpyrazine & [14,17] & [13,20,21] & [13,17,21,28] & entry, roasted, & \\  & 11 & 2-ethyl-3-methylpyrazine & [14,17] & [13,20,21] & [13,17,21,28] & transited, open, roasted, & \\  & 12 & 2-ethyl-3-methylpyrazine & [14,17] & [13,20,21] & [13,17,21,28] & hashler, roasted, raw potato, & \\  & 13 & 2-ethyl-3-methylpyrazine & [14,19,27] & [13,15,20,21] & [13,17,20,21,29,21] & transited, open, roasted, & \\  & 12 & 2-ethyl-3-5-dimethylpyrazine & [7,13,16,30] & [13,15,20,21,29,21] & [13] & [3,7,13,16,20,20,21,29,21] & transited, open, roasted, & \\  & 13 & 2-ethyl-3-6-dimethylpyrazine & [7,14,16,19,23,27,20] & [13,20,21,29,21] & [13] & [3,7,13,19,20,28,31] & transited, open, roasted, & \\  & 14 & 2-ethyl-5-6-dimethylpyrazine & [10,14] & [21,29] & [10,21,22,29,21] & shared, potato, earthty, unity & \\  & 15 & 2-diethyl-3-methylpyrazine & [14,17] & [17,28] & [17,28] & transited, open, roasted, energy & \\  & 16 & 3-5-diethyl-2-methylpyrazine & [14,19,23,27] & [13,20] & [13,19,20,28] & cross, chocolate, ram, roasted, nutty, & \\  & & & & & & & \\ \end{tabular}
\end{table} 
Table 1: The aroma profile of the pyrazines found in cocoa and chocolate. \begin{table}
\begin{tabular}{c c c c c c c c} \hline
**CNN** & **Compound name** & **LSOP in Cocoa** & **LSOP in DC** & **LSOP in MC** & \ \begin{tabular}{c} **LS of Odour Description from Literature** \\ **Description** \\ \end{tabular}  &