Coffee Science (E-Journal)
Not a member yet
873 research outputs found
Sort by
Physical and mechanical properties of the wood of coffee trunks and branches
Get PDFKnowledge of the physical and mechanical properties of coffee plants is essential to the development of mechanisms that perform the harvesting of their fruits by the principle of mechanical vibrations; however, these properties have yet to be determined in the laboratory. In this context, the present study aimed to determine the mechanical and physical properties of coffee plants through tensile and compression tests by means of a universal testing machine.Elasticity modulus, Poisson’s ratio, and specific mass were determined for specimens developed from the trunks and branches of 20 samples whole coffee plants, Coffea arabica variety, Catuaí Vermelho cultivar. The elasticity modulus was determined by the slope of the secant line in the elastic region of the stress-strain curve. Poisson’s ratio was determined by direct measurements in regions previously marked on the specimens. The conventional specific mass was obtained by the ratio between the mass of specimens and their volume. The methodology allowed the studied properties and a database to be obtained, and they can be used as a basis for the development and operation of the mechanism used in the mechanical and semi mechanical harvesting of coffee fruits. The results obtained indicate the following values for elasticity modulus of the trunk, performed from compression tests: 1090.94 MPa in the longitudinal direction and 108.60 MPa in the cross-sectional direction. For elasticity modulus of the branches, performed from tensile testsin the longitudinal direction: 507.72 MPa. For Poisson’s ratio, determined by direct measurements: 0.25 for the trunk and 0.09 for the branches. And for specific mass: 1070.05 kg.m-3 for the trunk and 1036.33 kg.m-3 for the branches.
Key words: Elasticity modulus; Poisson’s ratio; Specific mass; Geometrical properties
Indaziflam: Leaching and control of Urochloa plantaginea in applications on coffee litter with different rainfall simulations
Get PDFCoffee litter and the rain that occurs after the application of pre-emergence herbicides impact on their leaching and weed control effectiveness. The objective of this study was to evaluate the leaching and control effectiveness of indaziflam, applied on coffee litter, and under simulations of different amounts of rainfall. Two experiments in greenhouse were conducted with the application of indaziflam (0.1 kg of active ingredient - a.i. - ha-1), in a completely randomized design. The first involved the leaching of the herbicide using Urochloa plantaginea as a bioindicator, in a 8 x 4 factorial arrangement, with eight depths in the PVC column (0-0.05; 0.05-0.1; 0.1-0.15; 0.15-0.2; 0.2-0.25; 0.25-0.3; 0.3-0.35; 0.35-0.4 m) and four amounts of straw (0; 1; 3 and 5 t ha-1), this factor was isolated for rainfall simulations (10, 20 and 40 mm). The second experiment tested the effectiveness in controlling U. plantaginea, in a 4 x 3 factorial arrangement, with four amounts of litter (0; 1; 3 and 5 t ha-1) and three amounts of rainfall (10, 20 and 40 mm). Both experiments had four repetitions and controls without application of the herbicide. In leaching, a greater effect of indaziflam was found at a depth of 0-0.05 m, and the higher the simulated rainfall, the greater the phytotoxicity observed in U. plantaginea, with 39.75%, 52.50% and 92.06%, for rainfall amounts of 10, 20 and 40 mm, respectively. U. plantaginea showed high susceptibility to control by the herbicide indaziflam, and the lowest control, 82%, was observed when indaziflam was applied on 5 t ha-1 with simulation of rainfall at 10 mm. The increase in the amount of litter on the soil surface, combined with lower amounts of rainfall can reduce the leaching of indaziflam and the control of U. plantaginea.
Key words: Alexandergrass; Coffee plantation; Pre-emergence; Transport
Inhibition of Candida albicans growth by steeping freeze-dried robusta ground coffee
Get PDFCoffee contains active compounds that alleged to have antifungal activity. This study aimed to analyze inhibitory effect of steeping freeze–dried Robusta ground coffee (SFDRGC) to the growth of oral microorganism Candida albicans (the main causative agent of oro-pharyngeal opportunistic infection). This is an in vitro experimental study using the post–test only control group design. Serial dilutions of SFDRGC were studied. An antifungal drug Nystatin was used as a positive control, and sterile distilled water as a negative control. The inhibitory effect was study by means of Agar well diffusionmethod. Result showed that SFDRGC demonstrated antifungal activity. The higher concentration of SFDRGC showed the higher antifungal activities significantly (P < 0.05). Concentration of 100% SFDRGC showed anti-candida activity as potent as Nystatin. In conclusion, 100% SFDRGC demonstrated a potent antifungal agent against C. albicans. This study suggested that coffee beverage might be used as anti-candida mouthwash to prevent the risk of oral opportunistic infection. Further studies, however are needed to confirm this notion, such as epidemiological, and phytochemical studies of antifungal bioactive components in coffee that are processed using various methods.Key words: Agar well diffusion method; antifungal; nystatin; opportunistic infection
Comparison of sensory attributes and chemical markers of the infrared spectrum between defective and non-defective Colombian coffee samples
Get PDFDefects in coffee affect the sensory quality of finished drink. To avoid this, defective beans are usually removed after threshing, as, once the green beans have been roasted, it becomes difficult to identify the defects. Procedures have been developed to evaluate coffee samples using infrared spectroscopy to detect such defects. As such, this study evaluated infrared spectra and sensory attributes of 39 coffee samples in: commercial ground and instant coffees, medium and high roast quality coffees, and defects present in the coffee. The sensory analysis was performed by 10 judges, semi-trained by a Q-grader, and eleven attributes were assessed using a semi-structured hedonic scale. The spectra obtained from the coffee samples were processed by area normalization, first derivative, and second derivative, later followed by principle component analyses. The sensory results showed differences in the evaluated attributes, differentiating between the samples of high quality medium roast coffee from the other samples. Principal component analysis applied to IR spectra showed that when normalizing the data by area, the samples were discriminated, which explained 84% of variance; coffee defects in the samples of ground commercial coffee were separated from high quality coffee and instant coffee. Using the chemical descriptors obtained from the infrared spectra, it was possible to differentiate between high quality, commercial and instant coffee.
Key words: Coffee bean defects; FTIR-ATR; principal component analysis; quality coffee
The influence of natural fermentation on coffee drink quality
Get PDFCoffee quality refers to various methods used in farming, selective harvesting that assist in quality preservation and drying methods to be performed. Some drying methods that are being performed fermentation procedures have helped in obtaining specialty coffees. The objective of the research was to evaluate the effects of controlled natural fermentation of coffee through the temperature and time and its influence on the quality of coffee, according to the prescribed attributes in SCAA methodology, the type of coffee drink and time for drying grain. The research was carried out at Lavrinha farm, located at Poço Fundo (south of Minas Gerais), with coffee fruits of Catuaí Vermelho IAC 144 cultivar and selective and manual harvesting. The treatments with temperature-controlled fermentation of 30 and 40 °C (1, 2, 3, 6 and 12 hours) and the control treatment were used with three replications in a randomized block system (DBC) in a factorial scheme. After fermentation, the batches were dried to 11.5% humidity and evaluated according to the SCAA (2015)methodology. The natural fermentation induced by temperature (°C) and time (hours) directly influenced the drink quality, resulting in a coffee with a score of 82 to 84 points, with attribute aggregation and special classification. Natural fermentation with temperature up to 40 °C and time control of 3 ,1 and 24 hours resulted in an improvement in coffee quality by 84 points.
Key words: Control; Drying; Harvest; Monitoring
Agronomic performance of coffee in response to framework pruning in cycles of the “safra zero”
Get PDFIn this paper, we aimed at selecting genotypes of Coffea arábica L. that are responsive to framework prunin, with high productive potential and desirable agricultural features. We evaluated 18 progenies in the F5 generation, 8 of them being from the group Catucaí (breeding of seedlings of Red Catuaí with coffee seeds of the Icatu germplasm) and ten descendants from the Timor Hybrid (breeding of the Red and Yellow Catuaí with the Timor Hybrid), as well as two commercial cultivars as witnesses (Tupi IAC 1669-33 and Obatã IAC 1669-20). The experiment was carried out at the experimental field of the Federal University of Lavras. The coffee was pruned in August 2014 after the sixth crop and once again in August 2016, being two cycles in the “safra zero” system. The design used was in randomized blocks (RBD) with three repetitions and 20 treatments (18 progenies and two commercial cultivars) totaling 60 experimental plots. We evaluated the area under the progress curve of incidence and severity of leaf rust and cercosporiosis, the productivity (sacs há-1), sieve #16 and over (%), mocha-type grains (%) and apparent specific mass of grains (ton.m3). The genotype 12 (H516-2-1-1-18-1-4) was responsive to the framework pruning and kept its productivity stable in both pruning cycles, being efficient in such system of crop conduction, besides presenting low incidence and severity of coffee leaf rust and cercosporiosis and high sieve.
Key words: Timor hybrid; Cercosporiosis; Leaf rust
Assessing potential plants extracts to reduce Leucoptera coffeella (lepidoptera: Lyonetiidae) attack in coffee
Get PDFLeucoptera coffeella (Guérin-Méneville) (Lepidoptera: Lyonetiidae) is one of the major pests of coffee in South America, causing severe defoliation in plants. The problems involving chemical control and the risks of resistance evolution of the insect, justify the search for alternative methods for manage the species. Plants extracts appears to be a valuable tool for the management of L. coffeella, due to the potential of plants insecticidal properties of them being compatible with the integrated pest management. This study evaluated the effect of nine botanic aqueous extracts on the oviposition and biology of L. coffeella, under laboratory conditions. The extracts of Toona ciliata, Trichilia casaretti and Trichilia pallida decreased the oviposition rate of L. coffeella on coffee leaves. Along with Trichilia catigua, Chenopodium ambrosioides and Melia azedarach, these extracts were classified as deterrent to oviposition by a preference index and the C. ambrosioides, T. casaretti and T. ciliata extracts caused high egg mortality of L. coffeella. Extracts of seeds of A. indica and T. pallida affect negatively the development and survival of L. coffeella, reducing of mined area by the larva. These results elucidate the potential of these plants species for pest control and might be useful in integrated management programs for L. coffeella
Effect of lnf (cna - cnb) enzyme complex in the drying process and the coffee quality
No full textThe world demand for quality coffee is growing and the market is increasingly demanding for sustainable practices, leading coffee growers to search for new coffee processing processes always aiming for maximum quality. The objective of this work was to verify the benefits of using the LNF CNA - CNB enzyme complex in the postharvest process, in order to compare the results of drying time and the final beverage quality of the product. The research was carried out at Fazenda Iracema, municipality of Machado - Minas Gerais, with mechanically harvested coffees from the cultivar Mundo Novo, with 80% maturation, and the treatments were: natural and washed coffee, with and without application of enzymatic complex and drying in suspended, concrete and mixed courtyards (initially in the yard and finished in rotary dryers), the enzyme complex dosage was 1 ml CNB + 2.5 ml CNA per liter of water, applied to 60 liters of coffee. The experimental design was in randomized blocks, in a 2 x 2 x 3 factorial scheme (2- types of “washed or natural” processing; 2- with and without enzymatic application; 3 - “suspended, concrete and drying” drying forms), with 4 repetitions per treatment, totaling 48 experimental plots. The coffees were dried to 11.5% humidity and evaluated by the SCAA. It was concluded that the use of LNF (CNA - CNB) enzymatic complex in the coffee drying process did not influence the final drying time results, nor did it influence the coffee beverage aroma attributes. The drying forms directly influence the drying time.
Enzymes; post-harvest; specialty coffees
Soil chemical attributes in coffee growing with different agronomic techniques
Get PDFThe objective was to evaluate the effects on soil chemical attributes in a coffee growing area, according to different agronomic techniques used and their associations. The experiment was conducted in the field, in an experimental area at the Department of Agriculture - DAG, in Lavras - MG, from January 2016 to October 2018. Coffee was planted in January 2016, with Mundo Novo IAC 379-19 coffee seedlings, with a spacing of 3.6 m between rows and 0.75 m between plants in the planting row. The factors under study were arranged in a 3x2x5 factorial scheme, making a total of 30 treatments. In the plots, three soil managements were randomized (soil cover with polyethylene film, soil cover with brachiaria grass and conventional management of spontaneous vegetation). In the subplots, two types of fertilizers used in the fertilization of coffee trees were tested (conventional and increased-efficiency fertilizer). In the sub-subplots, four soil conditioners were tested (coffee husk, phosphogypsum, water retention polymer, organic compost), and the control without conditioner. Aimed to evaluate soil chemical attributes in coffee growing with different agronomic techniques through the evaluation of: soil pH, phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), aluminum saturation (m) and base saturation (V%), by soil analysis carried out in October 2018 and leaf analysis in December 2018. It is noteworthy that the chemical attributes of the leaf were used only for principal component analysis through multivariate analysis. The use of fertilization (with conventional fertilizers or those with increased efficiency), combined with the application of organic compost or coffee husk, provide increased soil pH, as well as the use of ecological management of brachiaria grass. The use of organic compost as a soil conditioner increases phosphorus availability in the soil. Coffee husk, as a soil conditioner, is an efficient potassium source for the coffee crop. The use of organic compost and phosphogypsum increases the calcium and magnesium contents in the soil. The use of organic compost and coffee husk was efficient in increasing the base saturation (V%) grown with coffee. The use of organic compost, coffee husk and phosphogypsum reduced aluminum saturation in the soil. Treatments associated with the use of organic compost improve calcium, phosphorus and magnesium levels, increase pH and base saturation, besides decreasing aluminum saturation.
Key words: Coffea arabica; soil managements; fertilizers; soil conditioners
Resistance of new Coffea canephora clones to root-knot nematode (Meloidogyne incognita) in the western amazon
Get PDFRoot-knot disease is among the main diseases affecting coffee crop. The plant selection to the development new resistant cultivars is among one the most efficient methods of control. The present work aimed to quantify the resistance responses of Coffea canephora clones to root-knot nematode Meloidogyne incognita in the Western Amazon. For this, 17 previously selected clones were evaluated in three experimental trials, carried out in the municipalities of Ji-Paraná and Porto Velho, Rondônia. The resistance to root-knot nematodes M. incognita were evaluated by the numbers of gall in the roots (NG) and by the reproductive factor (RF). The resistance response was also interpreted according the genetic diversity of the clones based in their morphological traits. The clones BRS3210, C12, BRS2314, BRS3137 and BRS1216 are resistant to M. incognita with RF of 0.34, 0.62, 0.79, 0.86 and 0.98, respectively. BRS3213, C125, C15, BRS2336, BRS3220 and C09 clones were classified as susceptible, with RF of 1.93, 1.95, 2.00, 2.31, 2.32 and 2.35. The BRS3193, C160and BRS2357 clones were classified as very susceptible, with RF values of 3.03, 4.41 and 5.82, respectively. The clustering based on the genetic diversity of morphological traits indicated that genotypes more similar to the Robusta botanic variety had lower RF. The hybrid plants showed intermediate degrees of resistance indicating the segregation for the character of the M. incognita resistance. The clones BRS3210, C12, BRS2299, BRS2314, BRS3137 and BRS1216expressed resistance responses to M. incognita with potential for growing resistant genotypes in the Western Amazon.
Key words: Coffee; root-knot disease; plant breeding; Amazonian