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Brazil is the largest producer, exporter and the second largest consumer of coffee in the world. The two most economically valuable species are Coffea arabica and Coffea canephora, which differ in their physical, chemical and, consequently, market value, quality and consumer acceptance. The objective of the present study was to differentiate arabica and conilon coffee species from the physicochemical properties of moisture, pH, titratable total acidity, soluble solids, total sugars, reducing and non-reducing sugars, total phenolics, chlorogenic acid, caffeine and trigonelline using Partial Least Squares Discriminant Analysis (PLS-DA). The study of the physicochemical analyzes of both species allows a greater knowledge of the constituents that discriminate them, being able to help in the identification of compounds capable of influencing the quality of the beverage, enhancing what each species has to offer the best in the elaboration of coffee blends arabica and conilon, besides the quantification of compounds that, because they are distinct in arabica coffee and conilon, can also be used in the identification of frauds. The model obtained by the PLS-DA showed a good separation between classes, that is, it effectively classified the arabica and conilon coffee samples, resulting in obtaining values of accuracy and accuracy of the model above 90 %. The variables that had the greatest weight, according to PLS-DA, in the discrimination of coffee species were pH, acidity, total phenolic compounds and caffeine.

The quality of the coffee is determined by the sensorial analysis, using subjective methods and it is known that this quality is related to the chemical constituents of the grains. The present study used infrared spectroscopy to correlate the chemical composition of the grain with the final quality of the product and to assist in the current evaluation method, generating more reliability in the process. This study applied the spontaneous and induced fermentation with starter cultures (yeast) to evaluate the sensory potential from the impacts generated by the types of processes adopted. The experiments were conducted in a randomized block design with five replicates, in a 3x4 factorial scheme, with three fermentation times: 24, 48, and 72 hours and four wet processes: Washed, Yeast fermentation, Fully washed without yeast, and Fully washed with yeast. Infrared spectra were taken in the medium region (FTIR-ATR) of the 34 samples generated by the treatments. Given that the method of determining the quality of coffee is subjective, based on scores given by cuppers, the FTIR-ATR spectra were used in the construction of chemometric models to predict sensory ratings given to the attribute 'acidity'. The mean error of prediction of the model constructed for the sensory score was 0.11. Sensory results indicated a higher score for the acidity attribute, in dry fermentation with yeast at the time of 48 hours, suggesting a new strategy for the production of quality robusta coffee.

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Conilon coffee represents almost 20% of all Brazilian coffee production, however, it is underrated in terms of sensory quality when compared to arabica coffee. It is noteworthy that coffees from the genus Coffea canephora, have a denser sensory profile, less sweet, less acid and with strong body pronouncement at the time of tasting. However, several processes are being developed and tested to improve quality and add value to the product, making conilon coffee producers must modify operational techniques and procedures. Thus, in this study in question, the experiments were conducted at Fazenda Venturim in São Domingos do Norte, Espírito Santo State. For the course in question, processes were adopted with the application of starter cultures (yeast) to optimize and modify the metabolic routes and consequently the sensory quality. An exploratory analysis, using the principal component analysis method (PCA), was applied to the medium infrared spectra of the 33 coffee samples generated by wet treatments in order to understand the influence of these different processes on the chemical composition and final quality. of coffee. Preliminary results indicate the potential for optimizing the quality of conilon coffee using wet processing using starter cultures.