Coffee Science - v.13, n.4, 2018

URI permanente para esta coleçãohttps://thoth.dti.ufv.br/handle/123456789/11109

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ATR-FTIR for discrimination of espresso and americano coffee pods
(Editora UFLA, 2018-10) Monje, Andrés Felipe Bahamon; Parrado, Lina Ximena; Gutiérrez-Guzmán, Nelson
Roasted and ground coffee for encapsulation in single-serve capsules compatible with keurig® and coffee powder obtained from Nespresso® commercial capsules were analyzed for pH value, titratable acidity, moisture content, water activity and color (lightness); a data matrix that contains the physicochemical properties and the absorbance measurements using a baseline of 1600 to 1800 cm–1 by FTIR-ATR technique, was evaluated through the combined methods of principal component analysis (PCA) and cluster analysis in order to discriminate between the types of capsules. In the PCA biplot two distinct groups can be identified and in the cluster analysis two groups are that correspond to the two types of capsules. The results reveal that FTIR-ATR based methods seem to be a promising alternative for the discrimination of coffee samples for the pods industry or for the type of consumption.
Fuzzy logic application and cluster analysis in the quality of the beverage from conilon coffee
(Editora UFLA, 2018-10) Lima, Julião Soares de Souza; Silva, Samuel de Assis
The quality of coffee beverages has been under study due to the demand of the consumer market for both arabica and conilon coffee. The aim of this work was to study beverage quality from different clones by means of sensory analysis, in 13 clones of the variety Victoria INCAPER 8142 produced at average altitudes of 100.0 m and 528.0 m and with the cherry fruits processed by natural drying or depulping. Fuzzy classification was adopted for the global scores obtained in the sensory analysis, on a scale of 70.0 to 100.0 points, with the Euclidean distance from the cluster analysis being used to define the dissimilarity between the global fuzzified scores for the different clones at the two altitudes and for the two methods of processing the fruit. Clones C4 and C10, at the intermediate maturation stage, presented a mean global score (GS) of 85.0 points for the coffee produced at the altitude of 528.0 m and for the depulped fruit, corresponding to a degree of fuzzy pertinence (FI) of 0.50, and being classified as fine coffee. These same clones presented dissimilarities in the beverage produced by the depulped fruit, with better quality for the coffee at the higher altitude. The fuzzy classification taken together with the cluster analysis to interpret the mean global scores (GS) in the sensory analysis of the beverage for the different treatments under study identified variation in beverage quality.
Performance of different fermentation methods and the effect on coffee quality (Coffea arabica L.)
(Editora UFLA, 2018-10) Peñuela-Martínez, Aida Esther; Zapata-Zapata, Arley David; Durango-Restrepo, Diego Luis
Fermentation of coffee mucilage is a spontaneous process caused by microorganisms growing in the environment, which is influenced by factors such as the coffee variety, climate and fruit maturity. These external factors play an important role in fermentation evolution because they have effect on the microorganism activity and the time for substrate transformation. The aim of this research was to asses different fermentation wet process and evaluate their effect on coffee quality (C. arabica ), as well as on organic acid concentrations and volatile organic compounds content, in the green coffee beans. The study was divided in two phases, one in which the pulping time was delayed and the fermentation methods were modified, and the second phase in which a bioreactor was used to control the pH and temperature of the coffee mass during fermentation. Two control treatments were used: without fermentation (mechanical removal of mucilage) and the traditional fermentation done in the farm. Significant differences in coffee quality were observed. The best quality was obtained from the treatments that used short process times and low temperatures. The concentrations of acetic, lactic and citric acids between the treatments and the control treatments were different. Higher contents of esters and ketones were found in the coffee that obtained the highest quality. The assessed processes lead to the conclusions that it is possible to improve coffee quality throughout introducing changes in the fermentation process, as well as modulating the acidity and fragrance of the final product.
Quality of natural and pulped coffee as a function of temperature changes during mechanical drying
(Editora UFLA, 2018-10) Oliveira, Pedro Damasceno de; Biaggioni, Marco Antônio Martin; Borém, Flávio Meira; Isquierdo, Eder Pedroza; Damasceno, Mariana de Oliveira Vaz
This research evaluated the sensory quality of processed and dried coffee beans in different ways. Two types of processing were used: dry and wet, besides seven drying methods: drying in yard and mechanical drying with heated air at 50 oC until coffee reached 30% (w.b.) moisture content, followed by drying with air heated to 35 oC until reaching 11% (w.b.) moisture content; drying in fixed-layer dryers with heated air at 45 °C until coffee reached 30% moisture content, followed by drying with heated air at 35 °C until reaching 11% (w.b.) moisture content; and drying in fixed-layer dryers with heated air at 40 °C until coffee reached 30% (w.b.) moisture content, followed by drying with heated air at 35 °C until reaching 11% (w.b.) moisture content; drying in fixed-layer dryers with heated air at 35 °C until coffee reached 30% (w.b.) moisture content, followed by drying with heated air at 50 °C until reaching 11% (w.b.) moisture content; drying in fixed-layer dryers with heated air at 35 °C until coffee reached 30% (w.b.) moisture content, followed by drying with heated air at 45 °C until reaching 11% (w.b.) moisture content; drying in fixed-layer dryers with heated air at 35 °C until coffee reached 30% (w.b.) moisture content, followed by drying with heated air at 40 °C until reaching 11% (w.b.) moisture content. The mechanical drying system consisted of three fixed-layer dryers, allowing the control of temperature and drying flow. Coffee was tasted according to the evaluation system proposed by the Specialty Coffee Association of America (SCAA). Physicochemical composition and physiological quality of the beans were analyzed, involving: grease acidity, potassium leaching, electrical conductivity, color and germination. The results show that pulped coffee is more tolerant to drying than natural coffee, regardless of how it was dried.
Sensory analysis of coffee dried with and without stirring
(Editora UFLA, 2018-10) Ribeiro, Bruno Batista; Câmara, Francisco Mickael de Medeiros; Mendes, Antônio Nazareno Guimarães; Silva, Virgílio Anastácio da; Montanari, Fernanda Faria
The production of quality coffees, with different sensory characteristics, is strongly related to drying techniques. Experiments were carried out on coffee fruits, with the presence and absence of the fruit turnover process during drying, using Catuaí Vermelho 144 coffee fruits, from the Cerrado Mineiro, processed dry and wet. The treatments consisted of natural coffee, natural green coffee, pulped coffee and semi-washed coffee fruits. They were carried out in a completely randomized design, with 4 post-harvest processes, 2 types of drying (with or without Stirring) and 3 replicates, totaling 24 plots. Natural green coffee and natural coffees were more responsive in the final scores, when not stirred during the drying process, unlike the coffees obtained by wet processing. Peeled coffees obtained the highest scores for the attributes, regardless of the adoption or not of stirring during the drying process. It was possible to obtain scores above 80 points by the SCAA protocol, without stirring the coffee.