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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 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 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 .