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    Sensory analysis and mid-infrared spectroscopy for discriminating roasted specialty coffees
    (Editora UFLA, 2021) Debona, Danieli Grancieri; Oliveira, Emanuele Catarina da Silva; Caten, Carla Schwengber ten; Guarçoni, Rogério Carvalho; Moreira, Taís Rizzo; Pereira, Lucas Louzada; Moreli, Aldemar Polonini
    In general, the process of roasting coffee uses a rotated fix drum or fluidized bed. Theoretically, the fluidized bed can provide more homogenous roastings throughout the process. Thus, in this study, we analyzed the sensorial and chemical attributes for two different coffees submitted to three roasting profiles using fluidized bed roaster. The coffees were roasted for a high temperature for a short time (HTST), medium temperature for a medium time (MTMT), and low temperature for a long time (LTLT). Sensory analysis was performed on the roasted coffees according to the SCA methodology and chemical analy sis through mid-infrared spectroscopy. The results of sensory analysis indicated a preference for MTMT roasting for coffee grown at high altitude and HTST roasting for coffee grown at low altitude. Chemically, coffees show that LTLT and MTMT roasts are most distant from each other in their chemical com position when roasting low altitude coffee, whereas the HTST and MTMT roasts are the most distant from each other when roasting high altitude coffee.
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    Chemical and sensory perception of robusta coffees under wet processing
    (Editora UFLA, 2020) Oliveira, Emanuele Catarina da Silva; Guarçoni, Rogério Carvalho; Castro, Eustáquio Vinicius Ribeiro de; Castro, Marina Gomes de; Pereira, Lucas Louzada
    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.