Modelação do perfil aromático do café através da torra: melhoramento de cafés de baixa qualidade e excelência para cafés de elevada qualidade.

The objectives of this project are as follows: - establish correlations between the volatile compounds profile (with a focus on the main key-odour compounds of roasted coffee) of healthy and defective coffee beans across different roasting strategies, i.e., using fluidized bed, drum, and microwave equipment. In this sense, the aim is to illustrate the feasibility of maximizing the formation of key-aroma compounds and/or minimizing off-flavour compounds by resorting different roasting conditions. Achieving these objectives implies the ability to customize the aroma profile, improve process control and, foremost considering this project’s aim, valorise green coffee beans and mitigate faulty post-harvest processing procedures and/or low-quality crops. These objectives respond to a growing concern of a high-value commodity considering the increasing quality criteria demanded and the climate change scenario which, as it will be referred to in section 5.B.2, is scarcely addressed. - develop analytical methodologies to determine groups of volatile compounds, namely, pyrazines, sulphur-containing compounds, phenols, and carbonyls, resourcing to the fan-assisted extraction approach before chromatographic analysis. The fan-assisted extraction approach is a pioneering strategy (Aguiar et al., 2023), a mean to quantitatively extract volatile compounds from a liquid sample into an acceptor solution, based on the full evaporation technique. This approach does not need of expensive/specific equipment (such as purge and trap systems) is much simpler to implement and can be easily assembled in conventional laboratories. Achieving these objectives means the development of analytical methodologies for critical groups of compounds with a wide range of applicability in food industry. - develop miniaturized low-pressure chromatographic systems for the determination of key aroma compounds at the micromolar level. Achieving this objective means developing ad-hoc analytical systems that are hand-sized, have high sample throughput, are easily assembled, and are low-cost, to be easily implemented in coffee roaster facilities for process control and improvement of the final product. In the overall scenario, this project aims to present solutions to tailor the volatile profile of final roasted coffee, which can be used to maximize the potential for high-quality coffees as well as to mitigate low-quality coffee crops. Furthermore, this project aims to present solutions to easily preview the potential of green coffee beans to achieve a desired aroma profile: roasting and analysis based on the methodologies herein to be developed, provide analytical responses within less than 1 h.