Revista Engenharia na Agricultura
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Item Sensory and physicochemical evaluation of traditional powder coffee(Revista Engenharia na Agricultura, 2020-07-13) Silva, Joana Moratto; Oliveira, Isabela Yasbeck; Muller, Nathália Maris Ribeiro; Rinco, Nicolli Maria; Zia, Luisa Lemes; Dutra, Mariana Borges de LimaCoffee is one of the most important products for the Brazilian economy. Due to this fact, its sensory acceptance is extremely important for both the consumer and the producer. The objective of this study was to evaluate the acceptance of six brands of traditional roasted coffee in the southern region of Minas Gerais. The samples were evaluated by 124 consumers through the following tests: acceptance for appearance, aroma, taste, texture and overall impression, ideal for bitter taste and body and, finally, purchase intention. In addition, colorimetric and soluble solids analyses were performed. According to the results obtained, sample D had the highest frequency of positive purchase intention, while sample A had the highest frequency of negative purchase intention. Sample F had the closest ideal bitter taste and, in relation to the body of the drink, sample C was considered the closest to the ideal. Sample F presented the highest acceptance for all attributes evaluated in the acceptance test.Item Uso do calcário e do gesso agrícola em duas épocas de implantação do Coffea arabica L.(Revista Engenharia na Agricultura, 2020-10-30) Costa, Bruna Penha; Duarte Júnior, José Barbosa; Rego, Carlos Augusto Rocha de Moraes; Costa, Antonio Carlos Torres da; Lana, Maria do CarmoO Brasil apresenta predominância de solos ácidos sendo necessário à sua correção para atenuar o efeito da acidez sobre as culturas agrícolas, em especial o café que é sensível ao pH baixo e a quantidade de cálcio no solo. Diante disso, o objetivo deste trabalho foi avaliar o efeito da adição de diferentes doses de calcário e gesso agrícola e seus efeitos nas características agronômicas do cafeeiro em dois experimentos com época distinta de implantação da cultura. O delineamento experimental foi em blocos casualizados, com quatro repetições em esquema fatorial 4 x 4, onde o primeiro fator foi constituído por doses crescentes de calcário e o segundo por doses crescente de gesso. O primeiro experimento foi conduzido no período do inverno - verão e o segundo experimento no período da primavera – outono. As variáveis analisadas foram altura de planta (AP), diâmetro do caule (DC), índice de área foliar (IAF), matéria seca foliar (MSF), matéria seca radicular (MSR) e comprimento radicular (CR). Ao analisar as médias dos experimentos se observou que no experimento I, a AP apresentou valores superiores a do experimento II, com acréscimo de 1,84 cm nessa variável. Para as demais variáveis DC, IAF, MSF e MSR no experimento II alcançaram um incremento superior em relação ao experimento I na ordem de 0,4 mm, 9,08 cm2, 1,54 g, 4,12 g respectivamente. As doses de calcário e gesso agrícola não proporcionaram alterações das variáveis agronômicas em ambas às épocas avaliadas, durante o período de seis meses após transplantio.Item Pyraclostrobin preserves photosynthesis in arabica coffee plants subjected to water deficit(Revista Engenharia na Agricultura, 2020-02-07) Peloso, Anelisa Figueiredo; Tatagiba, Sandro Dan; Amaral, Francisco José Teixeira; Cavatte, Paulo César; Pezzopane, José Eduardo MacedoThe objective of this study was to investigate the effect of pyraclostrobin on the photosynthetic performance of rabica coffee plants subjected or not to a water deficit, using the parameter of gas exchange (net CO2 assimilation, stomatal conductance, transpiration rate, and internal CO2 concentration and nocturnal respiration), chlorophyll fluorescence a parameters (minimum fluorescence, maximum fluorescence, maximum quantum yield of photosystem II, effective quantum yield of PSII, quantum yield of regulated energy dissipation and quantum yield dissipation non-regulated) as well as the concentrations of chloroplast pigments. In the plants maintained without water deficit, pyraclostrobin did not cause any alteration on the parameters of chlorophyll a fluorescence; however, it contributed to an increase in the level of chlorophyll a + b, CO2 assimilation and CO2 influx for the carboxylation sites of the stroma. Decreases in nocturnal respiration in plants treated with pyraclostrobin, submitted or not to water deficit seems to be a common strategy in reducing energy waste in the maintenance metabolism. Under water deficit, pyraclostrobin contributed to increase the photochemical yield, enabling plants to effectively prevent the capture, use and dissipation of light energy.Item Colouring of coffee grains related to different relative humidity of the drying air after partial drying(Revista Engenharia na Agricultura, 2020-11-23) Moreira, Rodrigo Victor; Corrêa, Jefferson Luiz GomesChanges in color of coffee grains are indications of occurrence of oxidative processes and biochemical changes, which can alter the taste and aroma precursors of the grains, resulting in lower beverage quality. Thus, the aim of this study was to evaluate the color characteristics of peeled coffee grains subjected to different relative humidity of the drying air after partial drying. Coffee (Coffea arabica) fruits were harvested in the cherry stage and were wet processed. The treatments were the results of the combination of three dry bulb temperatures and three dew point temperatures. The control of dew point temperature was performed only after the grains reach the partial drying. Considering the Tbd of 40 °C - 40 °C, the reduction of the Tpd (2.6 °C) increased the grains bleaching, while the increase of Tpd (16.2 °C) resulted in a more yellowish-red. Tbd of 40 °C - 35 °C and 35 °C - 35 °C are indicated for bluish-green color formation, associated with higher sensory quality. The Color Saturation (C*) of the coffee grains are highly correlated with the b* color parameter, while the tonality (Hue) is negatively correlated with the a* color parameter.Item Drying kinetics of peeled coffee submitted to different temperatures and relative humidity of the air of drying after partial drying(Revista Engenharia na Agricultura, 2020-12-15) Moreira, Rodrigo Victor; Correa, Jefferson Luiz Gomes; Andrade, Ednilton Tavares de; Rocha, Roney Alves daThe mathematical modelling is fundamental for the understanding of the related processes the drying, that influences the quality of the coffee drink. The objective of this study was to evaluate the influence of different relative humidity of the drying air after partial drying on drying kinetics of peeled coffees. Coffee fruits were harvested in the cherry stage and processed by wet, resulting in the portion of peeled coffee. Eleven treatments of drying were accomplished, being nine results of the combination of three dry bulb temperatures and three dew point temperatures, more two treatments without the control of the dew point temperatures. The control of the relative humidity by the dew point temperature was made after the grains reached the partial drying. Among the studied models, those of Diffusion Approximation and Modified Midilli were the most adequate for describing the drying process of the first and second part of drying respectively. The effective diffusivity coefficient of water in coffee grains ranged from 0.81 x 10-11 to 1.84 x 10-11 m² .s-1 during the first part of the drying and ranged from 1.49 x 10-11 to 3.29 x 10-11 m² .s-1 during the second part of the drying, increasing significantly with the reduction of the dew point temperature and increase of the dry bulb temperature.Item Influence of temperature and altitude on the expansion of coffee crops in Matas de Minas, Brazil(Revista Engenharia na Agricultura, 2020-02-20) Oliveira, Karine Rabelo; Ferreira, Williams Pinto Marques; Fonseca, Humberto Paiva; Souza, Cecília FátimaCoffee is among the most significant products in Brazil. Minas Gerais is the largest state producer of Arabica coffee. Coffee activity has excellent growth potential, which justifies the identification of new areas for expansion of the culture. This study aimed to determine factors that affect the spatial distribution of coffee plantations the most, as well as to identify areas with a greater aptitude for its expansion in the region of the Matas de Minas (63 municipalities). The MaxEnt software was used to elaborate a model capable of describing the area with the highest potential for estimating the probability of coffee adequacy. The elaboration of the model considered the records of occurrence, climatic and topographic variables of Matas de Minas, the second largest state producing region. The area under the curve (AUC), the omission rate and the Jackknife test were used for validation and analysis of the model. The model was accurate with an AUC of 0.816 and omission rate of 0.54% for the ‘test’. It was identified that the potential distribution of coffee in Matas de Minas is determined by changes in the annual maximum temperature, although it did not generate a significant gain when omitted, accounting for a considerable loss in the model. However, the most influential variables on the delineation of distribution were, the altitude and the annual average temperature. The most favorable areas for expansion of coffee culture in the Matas de Minas were found in the vicinity of the region of Alto Caparaó.Item Post-harvest of coffee: factors that influence the final quality of the beverage(Revista Engenharia na Agricultura, 2022-04-27) Silva, Camilla Sena da; Coelho, Ana Paula de Freitas; Lisboa, Cristiane Fernandes; Vieira, Gerival; Teles, Maria Carolina de AbreuBrazil is the world’s largest producer and exporter of coffee and the second largest consumer market. Brazil offer differentiated and high quality products to maintain its leading position in coffee production and export. However, Brazilian coffee has suffered some limitations in its commercialization in the international market, due to qualitative aspects. The development of taste and aroma is highly complex, since hundreds of chemical reactions take place at the same time, such as the breakdown of proteins, polysaccharides, trigonelline and chlorogenic acid, mainly in the roasting process. Then, it is necessary that, in addition to pre-harvest management, there are post-harvest practices that meet consumer demands regarding the final quality of the beverage. Studies on physical and chemical changes in the composition of coffee beans must continue to be performed in a comprehensive manner, since factors such as damage to coffee beans, drying methods, processing, storage time, type of packaging and chemical components are directly related to sensorial properties and thus define the quality of the beverage at this point of view. Thus, the objective of this review was to relate the physicochemical, biochemical and physiological characteristics of coffee beans after harvest with the quality of the product after roasting.