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URI permanente desta comunidadehttps://thoth.dti.ufv.br/handle/123456789/3352
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Item Maturation and detachment force for mechanized harvesting of irrigated Conilon coffee in the Brazilian Cerrado(Empresa Brasileira de Pesquisa Agropecuária - Embrapa, 2023-02-17) Santin, Mateus Rollemberg; Amabile, Renato Fernando; Malaquias, Juaci Vitória; Veiga, Adriano Delly; Brige, Felipe Augusto Alves; Sala, Pedro Ivo Aquino LeiteThe objective of this work was to determine the force required to detach fruits of Conilon coffee (Coffea canephora) genotypes in five maturation stages, to determinate the best stage for mechanized harvest, and to verify the possibility of future selections of genotypes adapted to mechanized harvesting. Harvests were carried out in the 2013/2014 crop season, and the detachment force was determined based for six fruits from each side of the crop row, collected randomly from the middle third of the plants. The detachment force curve was obtained for each cycle through logistic regression, using the R software. According to the duration of their cycle, the genotypes were divided into super early, early, medium, and semilate; the values of the coefficients of the detachment force curve equation were also obtained. There is genetic variability regarding fruit detachment force throughout the maturation cycle, which indicates the possibility of selecting genotypes adapted to mechanized harvesting. Fruit detachment force shows a considerable drop in the final stages of maturation. The raisin stage is the best for the mechanized harvest of irrigated Conilon coffee in the Cerrado.Item Optimization of the roasting conditions of arabica coffee cultivated in the cerrado area of Brazi(Instituto de Tecnologia de Alimentos – ITAL, 2018) Malaquias, Juaci Vitória; Celestino, Sonia Maria Costa; Xavier, Manaira Ferreira FrancoThe aim of this work was to optimize, by way of a rotational central composite design (RCCD), the roasting temperature and time conditions of beans from three Coffea arabica L. genotypes cultivated in the Cerrado, Brazil under controlled water stress conditions, to maintain a high soluble solids content and a roasting colour acceptable by consumers. In this way it will be possible to know the potential use of these genotypes in the instant coffee industry. The RCCD design was carried out with 2 factors (time and temperature) and 11 experiments for each of the three genotypes. The soluble solids contents were determined using a digital refractometer and the roasted bean colour evaluated using the Agtron system. The software R was used in both the variance analysis and in the multiple linear regression to define the prediction mathematical models and the statistical parameters. The Excel SOLVER tool version 2010 was used to select the best colour-soluble solids binomial to provide a colour from 65# to 45# (medium light to moderately dark) on the Agtron system and the highest soluble solids value. The roasting temperature and time conditions that maintained high soluble solids contents and produced roasted beans with an appropriate colour for consumption were 204.8 °C and 10.9 minutes for the cultivar MG 1177; 214.2 °C and 8.8 minutes for MG 0188; and 240 °C and 7 minutes for Icatu 2944, showing the potential for traditional consumption and the production of instant coffee.Item Models identity generated in neutron probe calibration in latosol cultivated with coffee and signalgrass(Editora UFLA, 2018-10) Borges, Inácio Barbosa; Rocha, Omar Cruz; Malaquias, Juaci Vitória; Fagioli, Marcelo; Sá, Marcos Aurélio Carolino de; Guerra, Antônio FernandoThe cover plants affects soil spatial variability interfering with soil moisture and density, leading to doubts about the need for calibration of the neutron probe for different management systems. The objective of this study was to evaluate the Model Identity Method in the verification of equality of linear regressions resulting from the calibration of a neutron probe for different layers, as a function of signalgrass management as a cover crop between rows of soil coffee crop in the Brazilian Central Cerrado. Aluminum tubes were installed to access the probe and two saturation basins were built in a coffee area, irrigated by a central pivot, in an Oxisol, with two management systems, T (Traditional with bare soil) and Sg (Signalgrass in the row). Samples were taken at depths of 0-0.20; 0.20-0.40; 0.40-0.60; and 0.60-0.80 m for determination of gravimetric moisture and density, and the volumetric moisture was determined to follow the drying of the soil. Concomitantly, measurements were taken with the neutron probe in these layers. Two calibration curves were constructed for each layer, which were compared by the above method. It was observed that treatment Sg yielded differences in soil water storage in the 0.20- 0.40 m layer, differing from treatment T. The statistical method allowed the observation of equality of regressions between treatments Sg and T at depths 0-0.20, 0.40-0.60, and 0.60-0.80 m; it also showed the need for different regression curves per layer, besides justifying the need for neutron probe calibration for each specific local condition.Item Agrupamento de acessos de café irrigado com melhores atributos para bebida(Editora UFLA, 2015-01) Celestino, Sonia Maria Costa; Malaquias, Juaci Vitória; Xavier, Manaira Ferreira FrancoA Embrapa Cerrados possui um Banco Ativo de Germoplasma de Coffea arabica L. com 900 acessos cultivados com a tecnologia do Estresse Hídrico Controlado com pivô central, sendo 30 deles considerados produtivos. Objetivou-se, neste trabalho, proceder ao agrupamento desses acessos produtivos de cafeeiro e posterior identificação de grupo(s) de acessos com os melhores atributos para bebida, além de determinar a contribuição relativa das propriedades físico-químicas e químicas para a divergência genética relacionada com a qualidade da bebida. Os frutos cereja das 30 cultivares foram processados por via seca. Parte dos grãos de café das 30 cultivares foi submetida à torração clara e parte permaneceu como matéria crua. O método de Singh foi utilizado para verificar o quanto as características pH, acidez total titulável, sólidos solúveis, proteína e polifenóis contribuem para a divergência genética observada entre os 30 acessos de café avaliados. A análise de Cluster permitiu a organização das cultivares de café homogêneas em quatro grupos (Clusters), sendo tal homogeneidade referente aos valores de variação das propriedades químicas e físico-químicas antes e após a torração, responsáveis pelo corpo e doçura da bebida (sólidos solúveis), pela acidez (acidez total titulável e pH), pelo sabor (polifenóis) e pelo aroma (proteína), sendo a menor redução de sólidos solúveis, o maior aumento de acidez, o menor aumento de polifenóis e a maior redução de proteína desejáveis para a escolha de cafés de qualidade. A variável polifenóis apresentou a maior contribuição para a diversidade genética com 28,84%, seguida de pH, proteína, sólidos solúveis e acidez com contribuições expressivas de 19,23%, 19,11%, 17,79% e 15,03%, respectivamente. O grupo 4, constituído pelos acessos Icatu 2944, MG0188, MG1177 e Topázio foi o mais promissor no que concerne à qualidade da bebida, pois esses acessos se caracterizaram pelo maior acréscimo na acidez total titulável e maiores reduções do teor de proteína após a torração. Esse grupo também apresentou valores de redução de sólidos solúveis e aumento de polifenóis após a torração mais apropriados ao consumo que os apresentados pelos demais grupos.