# Shedding Light on the Volatile Composition of _Broa_, a Traditional Portuguese Maize Bread
## 3 Results and Discussion
### Identification of Volatile Compounds in Maize Flour and Broas  
All twelve maize flours and corresponding _broas_ were analyzed using the optimized conditions. Illustrative chromatographic profiles of a maize flour (F1), corresponding _broa_ (B1) and wheat and rye flours are presented in Figure 1. Forty-four compounds were identified in maize flours and eighty-seven in _broas_ by comparison of their mass spectra with those from the software library and LRI from the literature. Their characteristic flavors, LRI, similarity indexes and retention times (RTs) are described in Table 2.  
Figure 1: Chromatographic profiles of _broa_ and maize, wheat and rye flours. Peaks are numbered according to Table 2 and letters represent compounds detected exclusively in rye and/or wheat flours, namely, A: \(\alpha\)-terpinolene, B: camphor, C: octanoic acid, D: 4-terpineol, E: \(\alpha\)-terpineol, F: linalyl acetate, G: nonanoic acid, H: 2(3H)-furanone-5-heptyldihydro. \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**Peak** & **B/F** & **RT (min)** & **Compound** & **SI (\%)** & **LRI** & **LRI** & **Odor Description** \\ \hline
**1** & B & 2.56 & **Acetic acid * & 94 & - & 600 (DB-5) [49] & Sour [20,49], acid, pungent [20] \\ \hline
**2** & B & 3.22 & **Acetic (D-hydroxy-2-butanone)** & 95 & - & 718 (DB-5) [49] & Butterscotch, battery, yogurt, creamy [23] \\ \hline
**3** & B & 3.74 & **Isopentanol** & 97 & - & 736 (DB-5) [49] & Balsamic, alcoholic [17,20], malty [20] \\ \hline
**4** & B & 3.82 & **2-Methyl-1-butanol** & 90 & - & 755 (DB-5) [49] & Wine, onion [49], malty [20] \\ \hline  & B & & & 97 & - & 769 (DB-5 MS) [50] & Fruity [20,49], balsamic, fused-like, sweet [20] \\ \hline
**5** & F & 4.65 & **1-Pentanol** & 96 & - & 769 (DB-5 MS) [50] & Fruity [20,49], balsamic, fused-like, sweet [20] \\ \hline  & B & & & 97 & 809 & \\
**6** & F & 5.56 & **Octane** & 94 & 809 & \\ \hline
**7** & B & & 97 & 813 & \\
**7** & F & 5.70 & **Hexanal * & 96 & 813 & \\
**8** & B & 6.87 & **Methylpyrazine * & 97 & 840 & 828 (DB-5) [49] & Popcorn [49], roasted, burnt, sweet [20] \\ \hline
**9** & B & 6.94 & **Furural * & 97 & 843 & 830 (DB-5) [51] & Almond, sweet [20,51], woody, fruity, flowery [51], bread-like, soil, burnt \\  & & & **(D-transchonabledyde)** & & & &asted, treated, treated [20] \\ \hline
**10** & B & 8.29 & **Furfuryl alcohol** & 96 & 865 & 866 (HP-5) [51] & Caramel-like [25,51], weak, fermented, burnt sugar, creamy [51], sweet, fruity [25], burnt, warm oil, mild [20] \\  & & & & 96 & 879 & \\
**12** & B & & & 96 & 879 & \\ \hline
**13** & B & 9.11 & **2-Butylfuran** & 94 & 895 & 893 (DB-5) [50] & Green [20] \\ \hline  & B & & 91 & 897 & \\
**14** & F & 9.16 & **2-Heptanone** & 96 & 897 & \\ \hline
**15** & B & 9.45 & **Nonane** & 87 & 904 & 900 (DB-5) [49] & Alkane [49], fused-like [51] \\ \hline
**16** & B & 9.54 & **4-Heptendal (D) * & 90 & 906 & 895 (DB-5) [51] & Biscuit-like, sweet [20,51], boiled potato, creamy [51], purtid [20] \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Identification of detected compounds in maize flows (P) and flows (B).