Coffee Science
URI permanente desta comunidadehttps://thoth.dti.ufv.br/handle/123456789/3355
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Item Profile of organic acids and bioactive compounds in the sensory quality discrimination of arabica coffee(Editora UFLA, 2018-04) Ribeiro, Diego Egídio; Borém, Flávio Meira; Nunes, Cleiton Antônio; Alves, Ana Paula de Carvalho; Santos, Claudia Mendes dos; Taveira, José Henrique da Silva; Dias, Laryanne Lopes de CarvalhoThis study was conducted to investigate the potential of organic acids and bioactive compounds present in rawbeans to differentiate the sensory quality of coffee from different genotypes and processing methods. During the 2010, 2011 and 2012 crop seasons, beverage quality was analyzed, as well as the profile of organic acids and bioactive compounds caffeine, trigonelline and chlorogenic acids (3,4 and 5-CQA) in raw coffee beans from genotypes Bourbon Amarelo and Acaiá. The samples were collected in commercial fields with altitudes ranging from 932 to 1391 m, in the municipality of Carmo de Minas, MG, Brazil. Two processing methods were adopted: dry process (natural) and wet process (mechanically pulped and demucilaged coffee). All harvest and post-harvest procedures were carried out according to the main technologies for the production of specialty coffees. The sensory analysis was performed using the methodology proposed by the Specialty Coffee Association of America (SCAA). Chemical analyses were performed by High performance liquid chromatography. Data were investigated using Principal Component Analysis (PCA). The variations in the contents of organic acids and bioactive compounds were due to the coffee processing method. For genotypes Bourbon Amarelo and Acaiá, the differences in the organic acid profile, associated with caffeine, trigonelline and chlorogenic acids (3,4 and 5-CQA), were essential to differentiate the quality of mechanically pulped and demucilaged coffee. No significant differences were observed in the sensory quality of natural coffee due to the analysis of organic acids and bioactive compoundsItem Quality of natural coffee dried under different temperatures and drying rates(Editora UFLA, 2018-04) Borém, Flávio Meira; Isquierdo, Eder Pedroza; Alves, Guilherme Euripedes; Ribeiro, Diego Egídio; Siqueira, Valdiney Cambuy; Taveira, Jose Henrique da SilvaThe final quality of coffees depends on the preservation of the cell membranes of the coffee beans, which can be damaged during the drying. Thus, the aim of this study was to assess the immediate and latent effects of the air temperature and drying rate on the sensorial quality of natural coffees, as well as its relationship with the chemical e physiological characteristics of the coffee beans. Mature fruits of arabica coffee were harvested and sundried to moisture content of approximately 35% (wb) and then moved into a mechanical drier under different conditions of drying. This process involved the combination of three dry bulb temperatures – DBT (35°C, 40°C, and 45°C) and two dew point temperatures – DPT (2.6°C and 16.2°C). Thus, the relative humidity of the air used for drying was a dependent variable of DTB and DPT, and as consequences, different drying rates were achieved for each DBT. The increase in the drying rate for the temperatures 35°C and 40°C has a negative effect on the final quality of natural coffee beans. However, for the temperature of 45°C, the effects of the drying rate on the coffee beans are overlaid by the thermal damages that are caused at this level of heating. Higher sensory scores for coffee are linked to lower values of electrical conductivity and potassium leaching of the exudate of the coffee beans, as well as lower values of fatty acids. It is emphasized that while the temperature of 35o C is recommended for the production of specialty coffees the temperature of 45o C is not.