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Item Physiological and sensorial quality of Arabica coffee subjected to different temperatures and drying airflows(Editora da Universidade Estadual de Maringá - EDUEM, 2017-04) Alves, Guilherme Euripedes; Borém, Flávio Meira; Isquierdo, Eder Pedroza; Siqueira, Valdiney Cambuy; Cirillo, Marcelo Ângelo; Pinto, Afonso Celso FerreiraThe objective of this study was to evaluate the correlation between a group of physiological variables (electrical conductivity, potassium leaching, and germination percentage) and a group of drying kinetics variables (drying time and drying rate) in addition to verifying the relation between drying kinetics variables and coffee quality as a function of processing type, temperature, and drying airflow. Coffee drying was conducted in a fixed-layer dryer at two temperatures and two airflows. After drying, an evaluation of the physiological and sensorial quality was conducted. Based on the results obtained, the following conclusions were drawn: coffee that is processed via a dry method is more sensitive to mechanical drying with heated air than coffee processed via a wet method, resulting in poor physiological performance; airflow does not interfere with the physiological quality of pulped and natural coffees; a temperature increase from 40 to 45°C resulted in a decrease in the physiological quality only for pulped coffee; and an increase in the drying rate as a result of an increase in the drying temperature to 40°C had a negative effect on the sensorial quality of pulped coffee.Item 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 VazThis 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.Item 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.Item Quality of natural coffee subjected to different rest periods during the drying process(Editora UFLA, 2012-07) Isquierdo, Eder Pedroza; Borém, Flávio Meira; Oliveira, Pedro Damasceno de; Siqueira, Valdiney Cambuy; Alves, Guilherme EuripedesRest periods during the coffee drying process may help improve the final coffee quality and reduce power consumption. The objective of the present study was to evaluate the effect of the moisture content of coffee fruit at the point when the drying process is temporarily interrupted on the quality of natural coffee using sensory analysis and electrical conductivity and potassium leaching tests. Ripe coffee fruits were manually and selectively harvested, sun-dried in a concrete yard for two days and subjected to mechanical drying in fixed-bed dryers. When the coffee reached moisture contents of 20%, 17% and 14% (wet basis, wb), the drying process was interrupted, and the coffee was allowed to remain at rest for 5, 15 or 30 days. Following this rest period, the coffee was dried in mechanical dryers until reaching a moisture content of 11% (wb). The control condition was complete drying in the yard. The combination of lowest moisture content with greatest period of rest and the combination of greatest moisture content and shortest period of rest resulted in the lowest values of potassium leaching. The beverage quality gradually improved as the duration of the rest period increased. Coffee subjected to a rest period at moisture contents of 17% and 20% (wb) did not alter the quality compared to that from drying in the yard.Item Drying kinetics of processed natural coffee with high moisture content(Editora UFLA, 2017-07) Siqueira, Valdiney Cambuy; Borém, Flávio Meira; Alves, Guilherme Eurípedes; Isquierdo, Eder Pedroza; Pinto, Afonso Celso Ferreira; Ribeiro, Diego Egídio; Ribeiro, Fabiana CarmaniniThe present study proposes a new processing and drying method and evaluates the behavior of grains subjected to this process through the water reduction rate and the adjustment of different mathematical models. Mature beans were divided into three batches. The first batch was continuously dried at 40±1 °C. The second batch consisted of natural coffee dried to moisture contents of 0.56±0.02, 0.41±0.02, 0,28±0.02 and 0.20±0.02 decimal (dry basis, d.b.), followed by processing and continuous drying at 35±1 oC and 40±1 oC. For all parcels, the drying process was ended when the coffee beans reached the moisture content level of 0.12±0.05 (d.b.). The third batch corresponded to the continuous drying of hulled and demucilated coffee at 40±1 °C. The experimental data were adjusted to ten mathematical models used to represent the drying of agricultural products. The grain water reduction rate was also evaluated. We concluded that the water reduction rate was highest for the drying temperature of 40±1 °C, especially at higher moisture contents. The total drying time for processed coffee with high moisture content was significantly reduced compared with the total drying time of natural coffee. The Midilli model satisfactorily describes the drying kinetics of processed coffee.Item Análise comparativa da infraestrutura de processamento utilizando um sistema de apoio à decisão para o cálculo de custos da fase de pós-colheita do café(Editora UFLA, 2014-10) Santos, Rafael Vargas Mesquita dos; Vieira, Henrique Duarte; Borém, Flávio Meira; Isquierdo, Eder PedrozaO dimensionamento da infraestrutura necessária para o processamento do café é decisivo na rentabilidade da atividade cafeeira, e dependerá de diversos fatores. Assim, em decorrência da existência de tantas variáveis é comum o produtor subestimar ou superestimar aspectos de infraestrutura. Objetivou-se,neste trabalho, analisar os aspectos de infraestrutura relacionados à área de terreiro e à capacidade dos secadores das fazendas, na fase de pós-colheita do café. Quarenta e seis fazendas das regiões do Cerrado, Matas de Minas e Sul de Minas Gerais responderam a um questionário elaborado no sentido de possibilitar essa análise. Ao empregar o sistema de apoio à decisão para o cálculo do custo da pós-colheita do café, ficou constatado que essas fazendas superestimam a área de terreiro e estimam corretamente a capacidade dos secadores.Item A decision support system to aid the calculation of the cost of the post-harvest processing of coffee(Editora UFLA, 2013-10) Santos, Rafael Vargas Mesquita dos; Vieira, Henrique Duarte; Borém, Flávio Meira; Isquierdo, Eder PedrozaVarious computer programs were developed to calculate the cost of the coffee harvest. However, few address the costs of coffee in its post-harvest stage. This study was aimed to develop a system for calculating the cost of the coffee post- harvest to facilitate decision making regarding the most cost-effective post-harvest processes. Thirty-four farmers in southern Minas Gerais state answered a questionnaire designed to validate this system. The use of a decision support system showed that the simulated costs in the post-harvest stage were not statistically different from the costs informed by the representatives of the selected farms.Item Cinética de secagem de café natural para diferentes temperaturas e baixa umidade relativa(Editora UFLA, 2013-04) Alves, Guilherme Euripedes; Isquierdo, Eder Pedroza; Borém, Flávio Meira; Siqueira, Valdiney Cambuy; Oliveira, Pedro Damasceno; Andrade, Ednilton TavaresDiante da importância da secagem na fase da pós-colheita do café e seu reflexo na qualidade final do produto, objetivou-se, neste trabalho, avaliar a cinética da secagem em diferentes temperaturas do ar de secagem, para uma baixa temperatura de ponto de orvalho de frutos de café arábica (Coffea arabica L.), processados via seca. Os frutos foram colhidos manualmente e submetidos à separação hidráulica. Para a secagem dos frutos, com teor de água inicial de 1,9 ± 0,1 kg.kg -1 (bs), utilizou-se secador mecânico a três temperaturas de bulbo seco (35 °C, 40 °C e 45 °C) para a mesma temperatura de ponto de orvalho (2,6 °C) do ar de secagem. Sete modelos matemáticos foram ajustados aos dados experimentais para caracterizar o processo de secagem dos frutos do cafeeiro. Os modelos de Henderson e Pabis modificado e de Resíduos Sucessivos com dois termo, foram os mais adequados para descrever o processo de secagem, sendo escolhido o de Henderson e Pabis modificado, pela maior simplicidade. A elevação da temperatura de bulbo seco, sob baixa temperatura de ponto de orvalho, provoca aumento no coeficiente de difusividade efetivo, na taxa de secagem e redução no tempo de secagem. Para as condições estudadas, o coeficiente de difusividade efetivo de água para os frutos do cafeeiro varia entre 1,908 e 3,721 x 10 -11 m2.s -1 . A energia de ativação para a difusão líquida, descrita pela equação de Arrhenius, foi de 52,89 kJ.mol -1 .Item Drying kinetics of natural coffee for different temperatures and low relative humidity(Editora UFLA, 2013-04) Alves, Guilherme Euripedes; Isquierdo, Eder Pedroza; Borém, Flávio Meira; Siqueira, Valdiney Cambuy; Oliveira, Pedro Damasceno; Andrade, Ednilton TavaresFaced with the importance of the drying in the post-harvest phase of coffee and its influence in the final quality of the product, the current study had the aim of evaluating the kinetics of the drying in different temperatures of the drying air for a low temperature at dew point of fruits of arabic coffee (Coffea arabica) dry processed. The cherries were manually picked and submitted to hydraulic separation. After that, the fruits with initial water contents of 1.9 ± 0.1 kg.kg -1 (bs) were submitted to the drying process under three temperatures of dry bulb (35 °C, 40 °C e 45 °C) for the same temperature of dew point (2.6 °C) of the drying air. Seven mathematical models were adjusted to the experimental data to characterize the dry process of coffee cherries. Henderson and Pabis modified and Successive Residue models with two terms were the most adequate to describe the dry process, being the Henderson and Pabis modified model chosen, for being more simple. The elevation of the temperature of the dried bulb under the low temperature of dew point causes an increase of the effective diffusivity coefficient, the drying rate and reduces the time of drying. For the conditions which were studied, the effective diffusivity coefficient of water for coffee fruits varies between 1.908 e 3.721 x 10 -11 m2.s -1 . The activating energy for the liquid diffusion, described by the equation of Arrhenius, was of 52.89 kJ.mol -1 .Item Eletrônica de microscopia varredura de grãos de café submetidos 227 a diferentes formas de processamento e secagem(Editora UFLA, 2013-04) Borém, Flávio Meira; Oliveira, Pedro Damasceno de; Isquierdo, Eder Pedroza; Giomo, Gerson da Silva; Saath, Reni; Cardoso, Renan AlvesObjetivou-se, no presente trabalho, avaliar alterações na estrutura de grãos de café processados e secados de diferentes formas. O experimento foi realizado com dois tipos de processamento: via seca e via úmida; e quatro métodos de secagem: secagem em terreiro, e secagem mecânica com ar aquecido a 50/40°C, 60/40°C e 40/60oC, onde a temperatura foi alterada quando os grãos de café atingiram 30%±2% (b.u.), com complementação da secagem até atingir 11%±1% (b.u.). O sistema mecânico de secagem utilizado constituiu-se de três secadores de camada fixa, o qual permite o controle da temperatura e fluxo de secagem. Durante o experimento foram coletados dados para a avaliação da dinâmica de secagem. Após a aplicação dos tratamentos, os grãos de cafés foram submetidos a estudos em microscópio eletrônico de varredura (MEV). A observação dos grãos de café em MEV mostrou que a temperatura de secagem de 50/40°C dos cafés despolpados apresentou resultados semelhantes aos cafés secados em terreiro, com pequena contração das células, sem sinais evidentes de ruptura. Pôde-se observar também que a utilização da temperatura de secagem 40/60°C foi a que mais causou danos às estruturas das células, independentemente do tipo de processamento. Verificou-se que os cafés preparados por via seca apresentaram maior desestruturação dos componentes celulares do que os cafés despolpados, bem como maior tempo de exposição desses cafés ao processo de secagem.