Engenharia Agrícola
URI permanente para esta coleçãohttps://thoth.dti.ufv.br/handle/123456789/10363
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Resultados da Pesquisa
Item An index to evaluate the acceptance of specialty coffees in consumer groups(Associação Brasileira de Engenharia Agrícola, 2020) Resende, Mariana; Cirillo, Marcelo Â.; Borém, Flávio M.Numerous factors are related to the individual sensory perception of consumers, which makes it impossible to adapt a model that explains their behavior. In this context and given the scarcity of statistical indexes that evaluate preferences for specialty coffees, new statistical methods should be studied. To this end, our study aimed to create an index that measures the acceptance of specialty coffees. The index was built considering the fit of regression models as a function of principal component scores. Validation was done by significance tests, whose probabilities were obtained by bootstrapping, considering the main measures used in diagnosing outliers as weights, with application to real data from different consumer groups. The coffee varieties Acaia and Bourbon were discriminated in relation to altitude. In conclusion, the index was adequate for the analysis and characterization of specialty coffees grown at different altitudes.Item Influence of different temperatures and airflows on drying of natural and pulped coffee(Associação Brasileira de Engenharia Agrícola, 2020) Alves, Guilherme E.; Borém, Flávio M.; Andrade, Ednilton T.; Isquierdo, Éder P.; Siqueira, Valdiney C.; Dias, Camila de A.This study aimed to evaluate drying kinetics for natural and pulped coffee, using diferente temperatures and drying airflows. For the conduction of the experiment, coffee fruits (Coffea arabica L. cv. Topázio) were harvested manually, selecting only ripe fruits and subsequent to the hydraulic separation. For drying the coffee, use a mechanical dryer with two temperatures (40 and 45°C) and four drying air streams (24; 60; 96 and 132 m3.min- 1.m-2). Twelve models for employees to describe the drying kinetics of coffees. Among the models used to describe the drying process of natural coffee and pulped coffee, according to the results of the coefficient of determination, relative mean error, standard deviation of estimates and distribution of waste distribution, proposed model for the Only one that presents fit for all as conditions study. The temperature of 45 ° C and the airflows of 96 and 132 m3.min-1.m-2 provide the shortest drying times regardless of the coffee processing type.Item Sorption isotherms and isosteric heat of pericarp and endosperm tissues of arabica coffee fruit(Associação Brasileira de Engenharia Agrícola, 2020) Dias, Camila de A.; Andrade, Ednilton T. de; Lemos, Isabella A.; Borém, Flávio M.; Barros, Ezequiel A.The aim of this study was to evaluate and model the hygroscopic equilibrium and isosteric heat curves of pericarp and endosperm tissues of arabica (Coffea arabica) coffee fruit, in different temperature and relative humidity conditions. Sorption isotherms were drawn under temperatures from 20°C to 70°C and relative humidity ranging between 10% and 90% until the product reached the equilibrium water content with the environment. The experiment was set up in a 4 × 4 factorial scheme (four relative humidity of the drying air and three tissues of the coffee cherry pericarp + endosperm [1: exocarp + part of the mesocarp, 2: mesocarp, 3: endocarp, 4: endosperm]), in a completely randomized design, with three repetitions. The results were examined by analysis of variance and regression using the STATISTICA 5.0 statistical software. Among the analyzed models, the ones that best fit the experimental data were modified GAB, for exocarp + part of mesocarp and mesocarp, modified Henderson, for endocarp, and Sabbab for endosperm. It was observed that, for all treatments, the lower water contents required a higher amount of energy to reach the equilibrium water content, and the integral isosteric heat decreased with the increasing equilibrium water content.Item Mathematical modelling and immediate and latent quality of natural immature coffee under different drying conditions(Associação Brasileira de Engenharia Agrícola, 2019) Andrade, Ednilton T. de; Lemos, Isabella A.; Dias, Camila de A.; Rios, Paula de A.; Borém, Flávio M.This work aimed to study the immediate and latent effects of different relative humidities on the quality of dried coffee fruits, describe the drying kinetics of natural immature coffee (Coffea arabica L.), and evaluate the mathematical model that best fits the experimental drying data. The drying was carried out in a fixed layer dryer coupled to a composite air conditioning system in which the drying air was controlled with an air flow of 20 m3.min1.m-2, at a temperature of 40 °C, and at relative humidities of 10%, 17.5% and 32.5%. Manually harvested coffee fruits were used and dried to a mean water content of 0.120 dry basis (d.b). After drying, the kinetic curve and the physical and physiological properties were determined. The coffee was stored in permeable packs for 6 months. The electrical conductivity, potassium leaching, and colour analysis were performed every 2 months. For the modelling adjustment, the models were tested, and the Midilli model had the best fit with the drying kinetics of the immature coffee. No immediate damage was observed in the physical and physiological quality of the coffees, and latent damage was perceived after 120 days of storage for the natural immature coffees.Item Variação da temperatura e do teor de água do café em secador rotativo usando lenha e glp como combustíveis(Associação Brasileira de Engenharia Agrícola, 2006-05) Reinato, Carlos H. R.; Borém, Flávio M.O presente estudo foi realizado no Pólo de Tecnologia em Pós-Colheita de Café, na Universidade Federal de Lavras - MG. Seu objetivo foi estudar a distribuição da temperatura e do teor de água na direção radial do secador rotativo. Para a realização do teste, foram usados, concomitantemente, dois secadores da marca Pinhalense, com capacidade de 5.000 kg cada; em um secador usou-se lenha e no outro GLP, como combustíveis para o aquecimento do ar. A medição da temperatura do ar de secagem e da massa de café foi feita por meio de termopares distribuídos em 18 pontos no secador. As leituras de todas as temperaturas, registradas em um indicador, foram feitas em intervalos de meia hora. A redução do teor de água foi acompanhada em nove pontos na massa de café. Observou-se que os valores da temperatura no plenum apresentaram menor oscilação na secagem quando se usou o GLP. Além disso, independentemente do tipo de combustível, foram observados gradientes máximos de até 25 °C na temperatura e três pontos percentuais no teor de água na direção radial, na seção central do secador, em razão dos maiores valores de pressão estática (637,84 Pa). De maneira geral, independentemente do combustível usado, o gradiente de temperatura observado longitudinalmente na massa de café foi bem menor do que na direção radial.