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Item Arabica coffee flow properties assessed using different roasts and particle sizes during storage(Instituto de Tecnologia de Alimentos – ITAL, 2022-02-18) Oliveira, Gabriel Henrique Horta de; Corrêa, Paulo Cesar; Oliveira, Ana Paula Lelis Rodrigues de; Vargas-Elías, Guillermo Asdrúbal; Calil Júnior, CarlitoFlowability of agricultural products is an important factor to be considered at post-harvest, thus impacting directly on number of operations and the design of machinery. This study aimed to evaluate and determine the K coefficient and flow properties as a function of different levels of roasting, grain size, temperature and storage. Coffee beans were roasted at medium light and moderately dark, then ground at fine, medium and coarse sizes. An additional coffee lot was not ground. Samples were stored at 10 ºC and 30 ºC and analyzed during storage (0, 30, 60, 120 and 180 days), regarding internal and external friction coefficients, angle of internal friction, effective angle of internal friction, wall friction angle (concrete, rough steel and wood) and lateral pressure coefficient (K coefficient). Angle of internal friction varied significantly due to particle size and roast degree. Moderately dark roast with fine particle size led to higher values (about 29.5 º) of wall friction angle. The wood sample was the material with the highest values of wall friction angle, followed by the concrete and steel samples, when compared at the same storage temperature, roast degree and particle size. Whole coffee was classified as free-flowing. Fine particle size leads to cohesive flow characteristic, according to the flow function. Coffee roasted at medium light, kept whole requires storage facilities with higher pressure support, accordingly to the K coefficient values.Item Kinetic modeling of water sorption by roasted and ground coffee(Editora da Universidade Estadual de Maringá - EDUEM, 2017-07) Baptestini, Fernanda Machado; Corrêa, Paulo Cesar; Oliveira, Gabriel Henrique Horta de; Cecon, Paulo Roberto; Soares, Nilda de Fátima FerreiraThe objective of this study was to model the kinetics of water sorption in roasted and ground coffee. Crude Arabica coffee beans with an initial moisture content of 0.1234 kg w kg dm-1 were used. These beans were roasted to a medium roast level (SCCA # 55) and ground at three particle sizes: coarse (1.19 mm), medium (0.84 mm) and fine (0.59 mm). To obtain the water sorption isotherms and the isosteric heat, different conditions of temperature and relative humidity were analyzed using the dynamic method at 25oC (0.50, 0.60, 0.70, and 0.80 of RH) and 30°C (0.30, 0.40, 0.50, 0.60, 0.70, and 0.80 of RH) and using the static method at 25oC (0.332 and 0.438 of RH). The GAB model best represented the hygroscopic equilibrium of roasted coffee at every particle size. Isosteric heat of sorption for the fine particle size increased with increments of equilibrium moisture content, indicating a strong bond energy between water molecules and the product components. The Gibbs free energy decreased with the increase in equilibrium moisture content and with temperature.Item Propriedades físicas de frutos de café robusta durante secagem: determinação e modelagem(Editora UFLA, 2016-01) Botelho, Fernando Mendes; Correa, Paulo Cesar; Botelho, Sílvia de Carvalho Campos; Vargas-Elías, Guillermo Asdrubal; Almeida, Mayra Darliane Silva Diniz; Oliveira, Gabriel Henrique Horta deObjetivou-se, com este trabalho, avaliar a influência do teor de água nas propriedades físicas dos frutos de café da variedade robusta (Coffea canephora), durante a secagem. Foram utilizados frutos de café no estádio de maturação cereja com teor de água inicial de, aproximadamente 1,7 (b.s.), secos numa estufa com circulação forçada de ar à 40 °C, até um teor de água final de, aproximadamente 0,13 (b.s.). Durante o processo de secagem foram avaliados o ângulo de repouso, a massa específica aparente, a massa específica unitária, a porosidade e a forma do produto (dimensões características principais, diâmetro equivalente, esfericidade, circularidade e a relação superfície-volume), analisados em função do teor de água. Verificou-se que a variação do teor de água, durante a secagem, influencia as propriedades físicas dos frutos de café analisadas. Com exceção da relação superfície-volume, todas as propriedades analisadas reduziram com a redução do teor de água. Observou-se ainda que os fatores tenderam à estabilidade para teores de água entre 0,42 e 0,68 (b.s.).Item Particle size and roasting on water sorption in conilon coffee during storage(Editora UFLA, 2016-04) Corrêa, Paulo Cesar; Oliveira, Gabriel Henrique Horta de; Oliveira, Ana Paula Lelis Rodrigues de; Vargas-Elías, Guillermo Asdrúbal; Baptestini, Fernanda MachadoThe aim of this work was to evaluate alterations on the water sorption of coffee due to the effect of roast, grind and storage in two temperatures (10 and 30 oC) during 180 days. Crude grain coffee (Coffea canephora) with average initial moisture content of 12.61 % (d.b.) was used. Grain was roasted at two levels: medium light (ML) and moderately dark (MD). Afterwards, grain was processed in three different particle sizes: fine (0.59 mm), medium (0.84 mm) and coarse (1.19 mm), besides the whole coffee lot. Samples prepared were then stored in two temperatures (10 and 30 oC). These were analyzed during six months, at five distinct times (0, 30, 60, 120 and 180 days) regarding moisture content and water activity. Furthermore, mathematical modeling and thermodynamic properties acquisition of the coffee moisture adsorption process were accomplished. A split plot design was used, in which plots consisted of storage period and split-plots consisted of a 2 x 4 x 2 factorial (two roasting degrees, four particle sizes and two storage temperatures), with five repetitions.It was concluded thatparticle size did not significantly affectedmoisture content of coffee, independently of roast degree; Sigma-Copace model best represented hygroscopic equilibrium for sorption of roasted coffee; with moisture content reduction, an increase of differential enthalpy and entropy of sorption and Gibbs free energy occurs.