Impacts of quaker beans over sensory characteristics and volatile composition of specialty natural coffees.

The objective of this study was to evaluate the volatile composition and the sensory effect of the presence of Quaker beans in natural specialty coffee beverage and, consequently, to confront the requirement of the Specialty Coffee Association regarding the total absence of Quaker beans in a natural specialty coffee batch. Sensory analysis and volatile composition were performed for three different colorations of Quaker beans, added separately to natural specialty coffee samples at seven different concentrations. Beans with color equal to or above Agtron 82.8 negatively affected the sensory characteristics of natural specialty coffee only from the presence of 7 Quaker beans in one cup (65 beans). Through the analysis of volatile composition, volatile compounds formed during roasting were identified in Quaker beans from precursors present in raw immature beans. Therefore, the color and sensory characteristics of Quaker are a consequence of the chemical composition of an immature bean.

Influence of fermentation conditions on the sensorial quality of coffee inoculated with yeast.

Fermentation is one of the post-harvest steps that influence coffee quality. This work evaluated the effect of Saccharomyces cerevisiae (CCMA 0543) and Torulaspora delbrueckii (CCMA 0684) inoculation on the quality of natural and pulped natural processed coffee in different producing regions. Yeast populations were assessed by the real-time polymerase chain reaction. Volatile and nonvolatile compounds were evaluated by gas chromatography-mass spectrometry and high-performance liquid chromatography, respectively. S. cerevisiae was predominant during spontaneous (average of 4 log cells/g) and inoculated (average of 7 log cells/g) fermentations in both processes. T. delbrueckii showed a similar population (3.79 log cells/g) in all assays. Glucose and fructose were the most detected sugars in coffee beans. Succinic acid was found at the end of the fermentative process. The lactic acid concentration was inversely proportional to ethanol concentration. Pyrrole and furan, which are volatile groups, allowed to differentiate the coffee processing methods. Yeast inoculation modified the sensorial profile and increased the coffee beverage scores by up to 5 points. S. cerevisiae inoculation was most suitable for pulped natural coffee, and T. delbrueckii inoculation showed the best performance in natural coffee.

Discrimination of the sensory quality of the Coffea arabica L. (cv. Yellow Bourbon) produced in different altitudes using decision trees obtained by the CHAID method.

BACKGROUND: Knowledge of the sensory profile of coffee quality, associated with genetic and environmental factors, is of utmost importance for the international market, as well as for the productive sector. In this context, the goal of this study was to classify the quality of Coffea arabica L., cv. Yellow Bourbon, according to different scores obtained through sensory evaluations based on the Specialty Coffee Association of America protocol (SCAA), and by means of decision trees resulting from applying the CHAID method (chi-square automatic interaction detection). To that end, we used a database with the sensory characteristics of cv. Yellow Bourbon and the environmental characteristics of the Mantiqueira de Minas region, State of Minas Gerais, Brazil. RESULTS: The method used exhibited promising results regarding accuracy and success rates in order to discriminate coffee sensory quality as a function of the production environment. The results obtained clearly show the effect of the coffee growing environment on the Yellow Bourbon variety, resulting in notable sensory differences in the beverage. CONCLUSION: It was possible to discriminate cv. Yellow Bourbon coffee samples, the sensory evaluations of which resulted in scores of ≥88 points, which are associated with growing environments at altitudes of ≥1200 m. © 2015 Society of Chemical Industry.