## 4 Conclusions  
This study aimed to extend previous research on the volatile compounds of broas, focusing on those mainly associated with the baking process. Almost 90% of the compounds identified in this work have not been previously detected in _bros_. One of the most relevant study findings was the absence of pyrrolines and the lack of pyrazines in _bros_, especially when prepared from traditional open-pollinated maize varieties. Thus, the absence of pyrrolines may contribute to the distinctive aroma of _broas_, and the high amounts of pyrazines may confer negative characteristics associated with the commercial hybrid maize _broa_ analyzed. Sulfur compounds, such as dimethyl trisulfide and methanethiol, were identified as the most likely contributors to the aroma of this ethnic bread. Some volatiles, such as oxathiane, have not been previously reported in similar foods, and their relevance to the overall aroma of foods is currently unknown. The data obtained in this study can be further explored for the purpose of fingerprinting traditional _broas_ since some compounds (2-methylpyrazine and 2-butyltetrahydro) were present in significantly higher amounts in the _broa_ prepared from the analyzed commercial maize hybrid variety. In conclusion, this work represents the most detailed study on the volatile composition of _broas_. It may contribute to disclosing possible volatiles of other bread and maize-based foods. These findings may have a number of important implications for future practice since better knowledge of the volatile compounds produced along the Maillard reaction may help to achieve the production of foods with sensory characteristics more appreciated by consumers.  
**Supplementary Materials:** The following supporting information can be downloaded at [[https://www.mdpi.com/article/10.3390/molecules27092728/s1](https://www.mdpi.com/article/10.3390/molecules27092728/s1)]([https://www.mdpi.com/article/10.3390/molecules27092728/s1](https://www.mdpi.com/article/10.3390/molecules27092728/s1)); Figure S1: Visual representation of the volatile baking compounds reported in the literature for several bread and maize-based foods (nodes), Figure S2: Picture of _broas_, Figure S3: Electron ionization mass of Pd8 (1-acetyl-1,2,3,4-tetrahydro)propyline and mass spectra of 1-acetyl-1,2,3,4-tetrahydro)pyridine and 2-acetyl-1,4,5,6-tetrahydro)propropline from the [PERSON] library, Figure S4: Heatmap and hierarchical cluster analysis representation of the 128 volatiles identified in broas. The content of each metabolite is illustrated through a chromatic scale, Table S1: Maize flours and _broas_ identification and description., Table S2: Average total peak areas and % of chromatogram area for the families of chemical compounds studied in _broas_, Table S3: Peak areas obtained for each sample (average of duplicates) and considered for the statistical analysis, Tables S4 and S5: Spearman correlation coefficients among the 128 studied _broas_ volatile compounds.  
**Author Contributions:** Conceptualization, A.B.-S. and M.R.B.; methodology, A.B.-S., M.S. and S.M.R.; software, A.B.-S., M.S. and C.P.C.; validation, A.B.-S., N.D., M.C.V.P., S.M.R. and M.R.B.; formal analysis, A.B.-S.; investigation, A.B.-S., M.S. and S.M.R.; resources, M.C.V.P., S.M.R. and M.R.B.; data curation, A.B.-S., M.S. and C.P.C.; writing--original draft preparation, A.B.-S.; writing--review and editing, A.B.-S., N.D., M.C.V.P., S.M.R. and M.R.B.; visualization, A.B.-S.; supervision, S.M.R. and M.R.B.; project administration, M.C.V.P., S.M.R. and M.R.B.; funding acquisition, M.C.V.P. and M.R.B. All authors have read and agreed to the published version of the manuscript.  
**Funding:** This research was funded by the European Union's Seventh Framework Programme for research, technological development and demonstration under grant agreement number 245058, by Fundacao para a Ciencia e Tecnologia through GREEN-IT - Bioresources for Sustainability R&D Unit (UIDB/04551/2020, UIDP/04551/2020) and LS4 FUTURE Associated Laboratory (LA/P/0087/2020).