Ciência e Agrotecnologia
URI permanente para esta coleçãohttps://thoth.dti.ufv.br/handle/123456789/9885
Navegar
180 resultados
Resultados da Pesquisa
Item Fermentação controlada em biorreatores artesanais para a produção de cafés especiais(Editora UFLA, 2024-04-26) Reyes, Etztli Itzel Morales; González, Martín Alejandro Bolaños; Balcazar, Julian Ovidio Cucuñame; Velasco, Jesús SalazarA model of an artisanal bioreactor was tested for fermentations in specialty coffee production, monitoring parameters such as Brix, temperature, pH, electrical conductivity, and total dissolved solids. The results demonstrated that the bioreactor effectively controlled these parameters, ensuring consistent processes and reproducibility, as well as uniformity in the final product. Both washed coffees, one with lactic acid bacteria (LAB) inoculation and one without, were produced and evaluated using the Cup of Excellence (COE) format. The coffee without inoculation scored 84 points, while the coffee with LAB scored 85.9 points. This highlights a significant positive correlation between LAB treatment and the sensory quality of the coffee produced.Item Development and evaluation of slow-release organomineral phosphate fertilizer based on coffee waste(Editora UFLA, 2024-05-31) Barbosa, Nathalia Silvestrin; Luz, Mario Sérgio da; Sousa, Nádia Guimarães; Santos, Kássia Graciele dosSlow-release fertilizers are sustainable alternatives to soil nutrition that can effectively enhance agricultural productivity. In this study, we formulated slow-release organomineral fertilizers using spent coffee grounds (SCG) impregnated with triple superphosphate (TSP). The effects of the composition of the fertilizer on pellet resistance and P release capacity were evaluated, along with heat treatment at different temperatures and times. The pellets with 10 g sugarcane molasses and 2.5 g TSP per gram of SCG, dried at 100 °C, presented the best mechanical resistance, releasing about 90% P in 13.8 h. The release kinetics of these pellets followed the Korsmeyer-Peppas model, controlled by Fickian diffusion. The fertilizer thermally treated at 400 °C for 30 min was classified as a slow-release fertilizer, as it released 90% P in 793.3 h. Thus, the partial carbonization of biomass promoted P adsorption to the surface of the porous matrix of the pellets, allowing the slow release of nutrients. Overall, we found that pelletized OMFs can be used as sustainable and inexpensive fertilizers derived from waste biomass; thus, their application can contribute to eco-friendly agricultural practices.Item Magnetic field in coffee seed germination(Editora UFLA, 2020-07-13) Braga Júnior, Roberto Alves; Azevedo, Roberto Luiz de; Guimarães, Renato Mendes; Reis, Leandro VilelaThe effective production of coffee seedlings faces many challenges, including seed germination. Therefore, a reduced seed germination period can be one of the most relevant contributions to enhance the testing and production of robust seedlings. The objective of this research was to evaluate the effects of a constant magnetic field on the germination of coffee seeds (Coffea arabica L.). The analyses were performed using a biospeckle laser (BSL) in conjunction with traditional seed viability tests. The coffee seeds were subjected to magnetic fields of constant intensity at values of 10 mT and 28 mT for a time interval of 6 days during their germination process. The embryo region was illuminated, and the images obtained by the BSL were processed. The activity levels of this region were compared with the data obtained using traditional physiological seed analysis. In addition to the results of BSL activity, the results of the seed analysis, such as isoenzymatic catalase (CAT), esterase (EST), superoxide dismutase (SOD), malate dehydrogenase (MDH) and endo-β-mananase, membrane integrity, germination, germination speed index (GSI), emergence speed index (ESI), and radicular protrusion levels, were obtained during the germination process. In conclusion, magnetic pretreatment with both intensities during the first six days of germination improved the permeability of the cellular membranes and advanced the activation of the antioxidant system, thus promoting faster and more uniform seed germination.Item Trolox equivalent antioxidant capacity of Coffea arabica L. seeds(Editora UFLA, 2022-08-08) Ferreira, Iara Alves; Fávaris, Nathália Aparecida Bragança; Rosa, Sttela Dellyzete Veiga Franco da; Coelho, Stefânia Vilas Boas; Ricaldoni, Marcela Andreotti; Costa, Marina ChagasThe causes of the low desiccation tolerance and low longevity of coffee seeds have not yet been fully elucidated, and a full understanding of their complex physiology is of great interest. Among several alternatives, the loss of antioxidant capacity in seeds may be related to their rapid loss in quality during storage. The objective of this study was to determine the total antioxidant capacity of coffee harvested at different ripeness stages before and after the storage of seeds with different water contents and to relate antioxidant capacity to physiological quality. Seeds in the greenish-yellow or cherry stages, recently harvested or stored for nine months at 10 °C with 40, 30, 20 and 12% water content (wet basis - wb), were submitted to physiological and biochemical quality evaluations, and the Trolox equivalent antioxidant capacity (TEAC) was determined. The germination and root protrusion of coffee seeds from greenish-yellow and cherry fruits were not affected by drying, but seeds harvested at physiological maturity had greater vigor when the moisture content was lower. The quality of coffee seeds decreased during storage, and this decrease was greater in seeds stored with higher water contents. Coffee seeds in the greenish-yellow stage had a higher antioxidant capacity than those in the cherry stage when recently harvested, but there was a substantial reduction in this capacity during storage at both maturation stages. Coffee seed deterioration is related to a reduction in antioxidant capacity, and the isoenzymatic profiles of the antioxidant process are little affected by the seed maturation stage. The deterioration of coffee seeds during storage is related to a reduction in their total antioxidant capacity, regardless of their maturation stage, being more pronounced in the greenish-yellow stageItem Nutritional characteristics of conilon coffee genotypes grown in transition altitude with water management in soil(Editora UFLA, 2021-10-27) Salles, Rodrigo Amaro de; Jordaim, Renan Baptista; Colodetti, Tafarel Victor; Rodrigues, Wagner Nunes; Amaral, José Francisco Teixeira do; Tomaz, Marcelo AntonioThe modification of water management in the Conilon coffee (Coffea canephora) crop is a possible strategy to improve nutritional management efficiency and ensure better use of the genotypes for regions of transitional altitude. The objective of this study was to evaluate the nutritional characteristics of 27 genotypes of C. canephora and submit them to two water management schemes in soil. The goal was to find evidence of higher leaf contents, exports, and nutrient recycling potential in the productive branches of various genotypes. The experiment was carried out in a randomized block design with three replications in a split-plot scheme. The treatment consisted of 27 genotypes of C. canephora and two water management schemes in soil (“Irrigated” and “Rainfed”). Nutritional content in leaves, exported by fruits, and pruned (leaves and stem of plagiotropic branches) recyclable contents were evaluated for nitrogen, phosphorus, potassium, calcium, and magnesium. Variations were observed among genotypes for all the parameters evaluated in both water management in soil. However, significant homogeneous groups were formed among the genotypes in the irrigated management. Furthermore, the genotypes showed distinct nutritional characteristics in response to water management in the soil. Genotypes 108 and 302 had higher nutritional content and were exported by fruits, regardless of soil water management.Item Seedling production of Coffea arabica from different cultivars in a modified hydroponic system and nursery using different containers(Editora UFLA, 2021-11-22) Lima, Amador Eduardo de; Guimarães, Rubens José; Cunha, Samuel Henrique Braga da; Castro, Elisa de Melo; Carvalho, Alex Mendonça de; Faria, Mauro Magalhães LeiteThe development of modified hydroponic cultivation has aroused interest and its use has enabled advantages in several crops, but studies for coffee are still scarce. Thus, the objective of this research was to evaluate seedling production of three Coffea arabica cultivars (Mundo Novo IAC-376-4, Catuaí IAC-62 Amarelo and MGS Paraíso 2), in a modified hydroponic system, and to compare it with the nursery production system, using plastic polyethylene tubettes and bags. Coffee seedlings in the development phase with cotyledon leaves, were cultivated in both cultivation systems. At 90 days after the implementation of the experiment, the seedlings were analyzed for growth (height, stem diameter, total number, leaf area, root area, root and shoot dry matter weight), and physiological characteristics (chlorophyll content and stomatal conductance). For the statistical analysis, a completely randomized design (CRD) was used in a factorial scheme 3 (cultivars) x 2 (containers) x 2 (cultivation systems), with four replications of ten plants per plot. The innovative production system of coffee seedlings in modified hydroponics, in combination with the use of polyethylene bags, provided greater growth of coffee seedlings with better physiological characteristics. Among the cultivars tested, MGS Paraíso 2 stood out with higher seedling growth (number of leaves, stem diameter and root and shoot dry matter weight).Item Physiological, biochemical, and ultrastructural aspects of Coffea arabica L. seeds under different cryopreservation protocols(Editora UFLA, 2021) Figueiredo, Madeleine Alves de; Rosa, Sttela Dellyzete Veiga Franco da; Ricaldoni, Marcela Andreotti; Pereira, Cristiane Carvalho; Coelho, Stefânia Vilas Boas; Silva, Luciano CoutinhoCryopreservation is a technique that may potentially conserve the germplasm of species of the Coffea genus for an indeterminate time. The aim of this study was to evaluate the physiological, biochemical and ultrastructural characteristics of cryopreserved seeds of Coffea arabica L., cultivar Catucaí amarelo IAC 62, which was subjected to different protocols regarding dehydration, precooling, cooling, rewarming and cathode water use. According to each protocol, the seeds were subjected to fast or slow drying to moisture contents of 17 or 20% (wet basis), cooled in different ways, and then immersed in liquid nitrogen for 24 hours. Different rewarming times in a water bath were also used. Physiological, biochemical and ultrastructural analyses were performed on the seeds after the cryopreservation steps. Moisture content at a 17% wb is the key factor for the cryopreservation of Coffea arabica L. seeds, which have better physiological quality and better preserved cell structures. Precooling of coffee seeds before immersion in liquid nitrogen does not provide advantages compared to direct immersion. The rewarming times tested (2, 4, and 6 minutes) and cathode water use did not cause changes in the physiological and biochemical quality or in the cell structures of Coffea arabica L. cryopreserved seeds. The pattern of cell structure observed in all seeds indicates that the damage from cryopreservation is less drastic in the cells of the embryos than in those of the endosperm, with the latter less tolerant to the stresses of dehydration, precooling, and rewarming.Item Diagnosis of leaf bacterial diseases of coffee reveals the prevalence of halo blight(Editora UFLA, 2021) Raimundi, Melina Korres; Souza, Ricardo Magela de; Figueira, Antônia dos Reis; Silva, Gustavo Matheus; Santos, Ana Carolina de Paula; Guimarães, Sarah da Silva CostaThe diagnosis of foliar bacterial diseases in coffee (Coffea arabica), such as halo blight (Pseudomonas syringae pv. garcae), bacterial leaf spot (P. syringae pv. tabaci), bacterial blight (P. cichorii), and dark leaf spot (Robbsia andropogonis), is considered a challenge for plant pathologists. The misidentification has been occurring when the diagnosis is solely based on symptoms and biochemical properties. Thus, the objective of this study was to identify and differentiate species and pathovars of Pseudomonas pathogenic to coffee plants, enabling a survey of the occurrence of these bacteria in the main producing regions of Minas Gerais state, Brazil. Firstly, the pathogenicity of the isolates was confirmed by inoculation in C. arabica cv. Catuaí Vermelho IAC 99. Then, biochemical analyses, combined with, repetitive element-polymerase chain reaction (rep-PCR) and phylogeny based on rpoD gene sequences were used to characterize 84 Pseudomonas isolates from coffee crops and nurseries. Based on rpoD-phylogeny, 73 isolates were identified as P. syringae pv. garcae, five as P. syringae pv. tabaci and six as P. cichorii. The rep-PCR results suggest a high genetic variability in populations of Pseudomonas syringae pv. Garcae and P. cichorii. This is the first report of the occurrence of bacterial leaf spot (P. syringae pv. tabaci) in the coffee-producing filed in Minas Gerais State. The findings confirmed the prevalence of P. syringae pv. garcae in coffee production fields in the State and the generated knowledge will contribute for the development of species-specific primers for the identification and detection of this pathogen.Item Ethiopian coffee germplasm is a valuable resistance gene pool to brazilian Pseudomonas syringae PVS garcae and tabaci(Editora UFLA, 2021) Rodrigues, Lucas Mateus Rivero; Destéfano, Suzete Aparecida Lanza; Beriam, Luís Otávio Saggion; Ferreiro-Tonin, Mariana; Braghini, Masako Toma; Guerreiro Filho, OliveiroSeven wild accessions of Coffea arabica from Ethiopia prospected by FAO Coffee Mission 1964-1965 were investigated concerning the resistance to 18 Brazilian strains and two Kenyan strains of Pseudomonas syringae pv. garcae and four P. syringae pv. tabaci strains, causal agents of bacterial halo blight and bacterial leaf spot, respectively. The cultivars of C. arabica IPR 102, resistant to the diseases, and Mundo Novo IAC 376-4, susceptible, were used as experimental controls. Our results indicated that the Ethiopian accessions presented high levels of resistance to all Brazilian strains of P. syringae pv. garcae but were susceptible to infection caused by Kenyan strains, which causes different levels of severity in wild accessions and experimental controls. Ethiopian accessions were also considered resistant to the four P. syringae pv. tabaci strains, with low susceptibility observed, one point on the severity scale, in access E-268 in response to a strain of the bacterium.Item Identification of physiological analysis parameters associated with coffee beverage quality(Editora UFLA, 2020) Freitas, Marcella Nunes de; Rosa, Sttela Dellyzete Veiga Franco da; Pereira, Cristiane Carvalho; Malta, Marcelo Ribeiro; Dias, Carlos Tadeu dos SantosThe demand for high-quality coffee among consumers has generated a great deal of interest among producers in serving this market. Parameters for physiological analyses that can be associated with aspects of sensory analyses of coffee can ensure more reliable results for coffee quality assessments. The aim of this study was to investigate the potential of physiological analyses in determining coffee quality through multivariate analysis. Several samples from coffee bean/seed lots were placed in cold storage at 10 °C, after which the sensory quality, physiological quality, and chemical characteristics of the beans were evaluated before storage and after three and six months of storage. The variables of physiological quality in the coffee beans were correlated with sensory analysis parameters. The viability of coffee embryos revealed by the tetrazolium test results were positively correlated with the final sensory analysis score. There was a correlation of root dry matter, hypocotyl dry matter, potassium leaching, and electrical conductivity with the sensory attributes that comprise the final sensory analysis score for the coffee beans. Variation in the final sensory analysis score was explained up to 97.14% by the variables radical emergence (r2 = 2.27%), strong normal seedlings, (r2 = 0.56%), seedlings with expanded cotyledonary leaves (r2 = 0.53%), tetrazolium test results (r2 = 91.54%), and potassium leaching (r2 = 2.24%). More studies are required to enable the use of physiological analyses to complement sensory analysis.