Preliminary study of variation in quality of fermented Coffea canephora genotypes using sensory assessment and mid-infrared spectroscopy

Coffee is one of the most widely consumed beverages in the world. The genetic variability of Coffea canephora has demonstrated significant differences in the chemical compositions of genotypes, resulting in different sensory profiles in the beverage. Fermentation can also affect the sensory quality of coffee beverage. Therefore, the objective of this study was to analyze the sensory profile and the chemical groups that contribute to the sensory qualities of the coffee beverage of C. canephora var. Conilon genotypes subjected to different fermentation processes. Fermentations were carried out with 4 L of cherry coffee or peeled cherry coffee for 36 h at 25 celcius. In the induced fermentation, the initial Colony Forming Unit (CFU/mL) was of 10(7) for Saccharomyces cerevisiae, Klebsiella sp, and Lactobacillus brevis. There was no microbial inoculation in the washed fermentation and the natural process. The sensory quality and chemical groups of the coffee were determined using the Uganda Coffee Development Authority Sensory Analysis Protocol with 6 Q-Graders and mid-infrared spectroscopy, respectively. The sensory and spectrometry analyses were able to distinguish the genotypes, highlighting the separations of genotypes A1 and Verdim with the worst sensory results, and genotype 153 with the best result. Groups formation through the mean Euclidean distance reinforces the sensory differences between fermentations. Furthermore, the greatest chemical changes in coffee beans were promoted by fermentation induced by S. cerevisiae. Thus, the genotypes and the type of fermentation influence in the sensory quality demonstrating potential for optimizing fermentations to improve the sensory quality of conilon coffee.