Coffee Science
URI permanente desta comunidadehttps://thoth.dti.ufv.br/handle/123456789/3355
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Resultados da Pesquisa
Item Fermented natural coffee followed by pulping: Analysis of the initial sensory quality and after six months of storage(Universidade Federal de Lavras, 2023-09-01) Salvio, Luís Gustavo Amaral; Cirillo, Marcelo Ângelo; Borém, Flávio Meira; Alves, Ana Paula de Carvalho; Palumbo, Juliana Maria Campos; Santos, Cláudia Mendes dos; Haeberlin, Luana; Schwan, Rosane Freitas; Nakajima, Makoto; Sugino, RyosukeIn recent years, different methods of fermentation have emerged for coffee, with the intention of adding complexity to its flavor. To be able to clearly identify the information from sensory analysis, tools capable of detecting small differences are needed. One such tool is multiple factor analysis (MFA). Thus, the objective of this experiment was to evaluate the effects of fermentation time and storage on the quality of sensory attributes using MFA. The coffee (Coffea arabica L.) samples collected for the study were from the Serra da Mantiqueira region – Brazil. In the present study, two natural coffee fermentation methods were evaluated, one using natural coffee microbiota (NF) and the other using a starter culture (Y), along with different times of anaerobic fermentation (0, 24, 48, 72, and 96h), followed by the pulping of the samples without the use of water. Sensory analysis of fermented coffee samples was performed immediately after drying and after six months of storage in permeable packaging in a refrigerated environment. Thus, the experiment was conducted in an intirely randomized design with a 2 x 5 x 2 factorial scheme (2 fermentation treatments; 5 fermentation times; 2 storage times). The highest scores and the attributes described in higher quality coffees, such as sweetness, acidity, and aftertaste, were attributed to coffees fermented for 96 hours. Results indicated that inoculation of the yeast Saccharomyces cerevisiae CCMA 0543 was responsible for maintaining the sensory qualities of the coffee fermented for 96 hours after 6 months of storage.Item Analysis and technical optimization of processing condition for better quality of robusta coffee production(Universidade Federal de Lavras, 2023-06-06) Ahmad, Usman; Sa’diyah, Khalimatus; Sathivel, SubramaniamThe wet processing of robusta coffee starts with harvesting coffee cherries, followed by sorting the cherries, pulping, fermentation, washing, drying, hard skin hulling, bean sorting, and packaging. Soaking fruit before pulping is an alternative for coffee farmers to delay the pulping process if time does not allow it. The fermentation process aims to remove mucus that is firmly attached to the hard skin. The addition of L. casei microbes can accelerate the process but affect the final taste. The study aimed to optimize the duration of soaking and fermentation processes for obtaining coffee beans with a minimum number of unpeeled beans, minimum partially black bean value, maximum taste quality, and to identify volatile components that play a role in forming the best steeping aroma after the coffee beans are roasted, ground and brewed. Experiments and data analysis were carried out using the Response Surface Method design. The optimization results showed that 24 hours of soaking and 24 hours of fermentation were the optimum treatment based on the criteria for unpeeled beans response, partially black bean value, and total taste score with a desirability value of 0.721. The identified volatile compounds (43) include 9 aldehyde group compounds, 3 alcohols, 4 furans, 5 heterocyclic N, 6 ketones, 1 organic acid, 3 phenols, 10 pyrazines, and 2 thiols. The spicy and chocolaty aroma produced was also the highest among treatments, namely 8.98% and 7.74%. The treatment without soaking and fermentation had the highest percentages of caramelly and nutty areas, namely 23.14% and 21.35%, respectively.Item Evaluation of the behavior of coffee stored in cooled and natural environments(Universidade Federal de Lavras, 2023-01-11) Andrade, Ednilton Tavares de; Rezende, Renan Pereira; Borém, Flávio Meira; Rosa, Sttela Dellyzete Veiga Franco da; Rios, Paula de Almeida; Oliveira, Filipe da Silva deThe market value of coffee is strongly influenced by loss of quality, which makes storage one of the main steps in the entire production chain. The finite element method (FEM) and computational fluid dynamics (CFD) are numerical and computational techniques that facilitate the simulation of agricultural product storage systems. Computational modeling satisfactorily represents real experimentation, simplifies decision-making, and reduces costs. This study aimed to analyze mocha coffee storage for 6 months in a cooled environment with temperatures between 15 and 18 °C and in a natural environment. The water content, bulk density, specific heat, thermal conductivity, and thermal diffusivity were determined and colorimetry and sensory analysis were applied to compare initial and final samples of the product after storage. It was found that the water content and specific heat were the only properties that presented significant changes. Through sensory analysis, it was observed that the quality of the coffee was the same for both systems. A computational model was developed to simulate the heat transfer process during storage. The comparison of the simulation results with the experimental results for the temperature distribution in the grain mass showed overall mean relative errors of 2.34% for the natural environment and 5.74% for the cooled environment.Item Effects of post-harvest process on volatile - sensory profile for coffee in Colombia(Universidade Federal de Lavras, 2022-12-28) Florez Arenas, Albeiro; Hincapie, Andres Mauricio Villegas; Ocampo, Gonzalo TabordaThe coffee fermentation process has been established as a determining stage regarding its quality and aroma. The objective of this study was to evaluate the differences that exist between five fermentation processes and within each process (at different fermentation times) based on their volatile and sensory profile. The processes evaluated were dry or natural (NA), semi-dry or honey (HO), and three variations of the wet process, called: conventional aerobic (AC), aerobic with previous fermentation in cherry (AFC) and anaerobic with previous fermentation in cherry (ANFC). The NA process obtained the highest score in the sensory profile and statistically different from the other processes. The volatile profile was determined by headspace solid phase micro-extraction (HS-SPME) and gas chromatography coupled to mass spectrometry (GC-MS). 51 volatile organic compounds (VOCs) were tentatively identified. The main chemical families that allowed differentiating between groups of processes were ketones and pyrroles, and the VOCs that mainly contribute to differentiate between process or groups of processes are: ethanone, 1-(1H-pyrrol-2-yl)-, 2,5-dimethylpyrazine, 2-furanmethanol, 4-vinylguayacol, 2-methylfuran, 2- butanone, 2,3-dimethylpyrazine, acetylpyrazine, 1- (2-furanylmethyl) -1H-pyrrole and 2,2'-bifuran. Within each fermentation process (between treatments) no differences were found from the final score of the sensory analysis, but differences were found from volatile profile.Item Evaluation of species transfer models in the cfd simulation of fixed bed soybean drying(Editora UFLA, 2021) Mateus, Felipe Leonardo Barcelos; Faria, Mauro Magalhães Leite; Petri Junior, IrineuThe drying is fundamental to the preservation of materials, particularly food, which is sensible to damaging related to moisture because of its hygroscopic nature. The drying increases the shelf life of these products and reduces their overall weight, which facilitates the logistics and aggregates value to the product. Computational Fluid Dynamics is a potentially facilitating tool for the analysis of drying variables, such as velocity, air temperature, and particle temperature, which have great influence on the drying rate. This work aimed at studying different numeric models for the simulation of a fixed bed drying operation, analyzing the influence of the equilibrium ratio and water diffusivity in the solid on the results. The computations were made in the software FLUENT 19.2, using the Multiphase Eulerian Granular Model with packed bed configuration and different mass transfer models: Constant, Species-Con stant, Species-Sherwood, Ranz-Marshall, and Hughmark, as well as heat transfer models: Constant Heat Transfer Coefficient, Constant Nusselt Number, Ranz-Marshall, and Hughmark. The mass transfer models with the best performance were the Ranz-Marshall and Hughmark models. A strong influence of the equilibrium ratio was observed for both models, and a moderate influence of the water diffusivity. The influence of equilibrium ratio and water diffu sivity was not observed for the other models. The heat transfer models did not present expressive difference, and the system reached thermal equilibrium quickly. The overall study of the models and the influence of different parameters was effective, and was able to document the obtained results for future optimization and further investigation of the numeric model.Item Post-harvest processing of coffee: an overview(Editora UFLA, 2021) Das, SuryatapaCoffee is known as one of the most popular beverages around the world. Coffee belongs to the botanical family Rubiaceae and genus coffea. The two most economically important species are C. arabica (arabica coffee) and C. canephora (robusta coffee).The health benefits of coffee are due to presence of many biologically active components such as caffeine, chlorogenic acid, nicotinic acid, quinolinic acid, trigonelline, tannic acid, and pyrogolic acid. The postharvest processing of coffee cherry involves dry or wet processing, grading, sorting, marketing, blending, and roasting. A series of physical and chemical changes occur during coffee roasting that are responsible for the development of pleasant aroma and flavour of coffee.Item Modeling effectiveness analysis of momentum and heat transfer in a fixed bed silo-dryer through computational fluid-dynamics(Editora UFLA, 2021) Mateus, Felipe Leonardo Barcelos; Petri Júnior, IrineuThe drying procedure is of great use in the industry, being capable of increasing the shelf life of many products, in addition to facilitate its transport and storage. The operation is essential for coffee beans to remove their excessive moisture content. The silo-drier has potential to ensure sensorial qualities through the intermittent drying, as well as with optimizations in the energy consumption. The objective of this work was to study the optimization of the numeric representation of a silo-dryer system, comparing the results of three different models available in the software FLUENT® 19.2: Eulerian Multi phase Model for Granular flow with packed bed configuration disabled, the same model but with the packed bed configuration enabled, and the porous zone single-phase modelling. The convergence efficiency of these models was also analyzed through the results of the numeric residue, and the influence of the relaxation factor in the simulation results. The behavior of solid volumetric fraction, air velocity and bed temperature were qualitatively examined with hot air at the inlet. It was found that the momentum relaxation factor influenced the results. Moderately lower factors allowed for faster convergence without significant particle behavior change. Monitoring the mass residue, the enabled packed bed modelling presented lower residuals, while the porous zone modelling presented higher residuals. The packed bed and porous zone modelling reported lower air velocities in comparison to the disabled packed bed modelling, and presented satisfactory heat transfer through the temperature profiles.Item Cold coffee seeds storage with different water content(Editora UFLA, 2021) Penido, Amanda Carvalho; Reis, Venícius Urbano Vilela; Rezende, Édila Maria de; Rocha, Debora Kelli; Oliveira, João Almir; Rosa, Sttela Dellyzete Veiga Franco daCoffee seeds are classified as intermediate because they have low tolerance to desiccation and low longevity. Consequently, moisture control and storage conditions are important factors in maintaining the physiological quality of these seeds. Thus, the objective in this work was to evaluate the water content effect on coffee seed longevity. Seeds of five Coffea arabica cultivars from the 2016/2017 crop were used. Part of the harvested seeds was dried in the shade until reach 12% moisture and the other part did not go through drying process, remaining with 40% water content. The seeds were stored in a cold chamber at 10 ºC for a period of nine months, and the physiological quality was evaluated every three months by germination, root protrusion, seedlings with expanded cotyledonary leaves, seedling dry mass and enzymatic analysis of catalase enzymes and superoxide dismutase. Regardless of the cultivar, wet seeds coffee storage provides better maintenance of physiological quality for up to nine months. Seedling vigor is reduced throughout the storage period, regardless of seed water content.Item Classification of the maturity stage of coffee cherries using comparative feature and machine learning(Editora UFLA, 2021) Velásquez, Sebastián; Franco, Arlet Patricia; Peña, Néstor; Bohórquez, Juan Carlos; Gutiérrez, NelsonThis work presents the use of multiple techniques (i.e., physicochemical and spectral) applied to harvested coffee cherries for the postharvest classification of the maturity stage. The moisture content (MC), total soluble solids (TSS), bulk density, fruits’ hardness, CIEL*a*b parameters and the dielectric spectroscopy methods were applied on coffee cherries at seven maturity stages. These maturity stages were assessed according to the days after flowering (DAF) and the physical appearance as traditionally performed by growers. An increase of the green-to-red ratio (i.e., a*) parameter was perceived, accompanied by a monotonic response for the hardness, TSS and bulk density with a maximum moisture content at stage 5. In the case of the dielectric spectroscopy technique, the loss parameter presented higher losses for unripe stages at the ionic conduction region. To compare the individual performance of each of the techniques, three machine learning methods were used: random forest (RF), support vector machine (SVM) and k-nearest neighbours (k-NN). The meta-parameters for these techniques were optimized for each case to achieve the best performance possible. Furthermore, as the dielectric response is of spectral nature, recursive feature selection was applied and the 500 MHz to 1.3 GHz frequency range selected for the task. The highest performance was obtained for the colorimetric (75.1%) and hardness (72.5%) responses, while the lowest was obtained for the moisture content (45.5%). The dielectric spectroscopy response presented a promising response (56.8%), that achieved a clear separation of unripe from ripe stages, except for stage 5 in which some of the samples were classified as stage 2. Most techniques studied are compatible with field conditions, and the dielectric technique shows potential to be transferred based on available software-radio defined platforms.Item Isolation and identification of a native microbial consortium for the coffee pulp degradation above 2000 masl(Editora UFLA, 2021) Cuba, Marcela N. Arteaga; Dilas-Jiménez, Josué O.; Díaz, Norberto Villanueva; Miranda, Ofelia C. Cernaqué; Santillán, Segundo M. Tafur; García, José Enrique Olivera; Mugruza-Vassallo, Carlos A.Pulp and mucilage constitute the most abundant by-products of the processing of coffee and inadequate handling produces high-rates of pollution. Considering that in nature there is a large variety of cellulolytic microorganisms which can intervene in the degradation of coffee pulp, the inclusion of a native microbial cellulolytic consortium was assessed. The sample for isolation consisted of coffee pulp and soil from a humid forest at more than 2,000 masl. Nutrient agar was used as a means of isolation for bacteria, and malt agar for fungi, supplemented with 50% soil extract and 1% carboxylmethylbcellulose. This achieved the isolation of 118 strains of bacteria and 114 of fungi. Cellulolytic activity was established using the filter paper test, assessing and selecting only those that presented higher glucose production, among them 12 strains of fungi and 11 strains of bacteria. To obtain the microbial consortium, randomized blends were performed for both fungi and bacteria, again assessing the production of glucose. The bacterial consortium was made up of Ochrobactrum pseudo grignonense, Paenibacillus lauruscon and Bacillus xiamenensis and the fungal consortium by Fusarium sp., Penicillum sp., Cylindrocarpon sp. The optimal treatment achieved a complete degradation of the pulp in 28 days, that would contribute to the recovery and conservation of the coffee ecosystem. The main interpretation was that a wet environment at more than 2,000 masl is still suitable for coffee composting but different bacterial and fungi consortia were found to support other recent work done with one type of consortium.