Coffee Grains Research Articles

Removal of hydrogen sulfide from biogas using activated carbon synthesized from different locally available biomass wastes - a case study from Palestine

ABSTRACT The main aim of this study was to remove hydrogen sulfide (H2S) from biogas by adsorption using synthesized activated carbon prepared using locally available biomass. The effect of the type of precursors, impregnation reagent and bed height was studied in continuous reactors. Three types of biomass wastes (almond shells, eucalyptus and coffee grains) were collected, grinded, sieved, pyrolyzed at 500°C and impregnated with chemical reagents such as potassium hydroxide or zinc chloride. Adsorption tests were performed using a fixed bed filter filled with the produced activated carbon. The highest biochar yield of 36% was obtained eucalyptus followed by almond shells (28.5%) and coffee grains (24%), respectively. The highest adsorption capacity and removal efficiency were obtained with eucalyptus followed by almond shells and coffee grains, respectively. For instance, eucalyptus showed an adsorption capacity of ~690 (mg hydrogen sulfide/g adsorbent) followed by almond (230 mg hydrogen sulfide/g adsorbent) and coffee grains (22 mg hydrogen sulfide/g adsorbent). As an impregnation reagent, potassium hydroxide gave the highest adsorption efficiency and capacity than zinc chloride. Furthermore, the breakthrough time with KOH (180 min) was higher than ZnCl2 (70 min). Increasing the bed height during continuous breakthrough tests increased the adsorption capacity and hydrogen sulfide removal efficiency. The results of this study showed that the adsorption efficiency of the synthesized activated carbon and consequently the hydrogen sulfide removal efficiency could be fine-tuned by selecting an appropriate biomass precursor and proper impregnation reagent.

¿Qué hay detrás del café? Transformación agrícola, mercado de tierras y sociedades comerciales en la producción cafetera del Valle del Cauca (1900-1930)

Este artículo busca examinar el crecimiento de la producción cafetera en Valle del Cauca entre 1900-1930. Este fenómeno será estudiado desde los factores que lo hicieron posible en el mercado interno, centrando su análisis en dos pilares claves: (i) la expansión de la frontera agraria a nivel comercial (mercado de tierra) y (ii) el papel desempeñado por las casas comerciales especializadas en las actividades de producción, procesamiento y exportación del grano. Los resultados de esta investigación señalan que cada uno de los cambios implementados a nivel regional repercutió en la modernización de la agricultura. Además, se muestra que la exportación de café ayudó a arraigar la conexión con el mercado mundial, lo que a su vez derivó en nuevas oportunidades económicas para los actores (productores, comercializadores y empresarios) al acceder a mercados, créditos, puertos y mercancías. Esta construcción fue posible gracias a la información consignada en las fuentes analizadas dentro del ámbito local y regional, como los protocolos notariales que permitieron detallar las transacciones que efectuaban los actores sobre la tierra y dentro del ámbito de los negocios comerciales, así como las relaciones de crédito existentes; además de la gran variedad de fuentes contemporáneas que entregarían datos sobre el mundo de la economía cafetera.

Análisis del tostado del grano de café

Analyzing coffee grain roasting operations - Veracruz Region will contribute to the distribution of equipment and machinery in the Industrial Engineering workshop of the Educational Program. It aims to obtain improvements in the roasting process through the study of the work (January–June 2019), to lay the foundation for the proposals of Systems of Quality Management, Safety and Environmental Care in the following phases of the project (2019-2020) with effects on continuous improvement. In the coffee industry in Mexico has in the medium and long term, opportunities to grow and consolidate. As with most agricultural products from smallholders, such as coffee, the prices paid for the input ("cherry coffee") They are far from what the processed coffee comes to obtain in presentations of soluble and ground powder for coffee makers, and the process of improvement, quality, efficiency in roasting activities is necessary. The method analyzed the case studies of the operations of companies, producers and research related to the coffee and coffee industry and the interpretation of the statistical results.

Impact of pumpkin seed oil and coffee treatment on the characteristics of semi-hard cheese

Semi-hard cheese was made from fresh domestic cow milk and treated with pumpkin seed oil and coffee during its ageing. The energy value and composition of the cheese were examined by determining the content of dry matter, minerals, proteins, fat, caffeine and fatty acids. During the ageing period, the cheese was dipped into a sweet, freshly-prepared, high-quality coffee drink and coated with a mixture of milled coffee grains and cold pressed pumpkin seed oil to improve the sensory properties of the cheese, but also to improve its nutritional value. It is considered that treated cheese could have greater nutritional and pro-health properties then untreated cheese, due to nutritional and healing properties of pumpkin seed oil and coffee used during the maturation period. Pumpkin seed oil contains carbohydrates, minerals, proteins, and important unsaturated fatty acids, while coffee is rich in antioxidants and helps in the prevention of type 2 diabetes, Parkinson's and Alzheimer's disease, and high cholesterol. To determine the impact of the treatment, the fatty acid and caffeine contents were determined by the GC-FID and the UPLC-DAD method. The cheese treated with pumpkin seed oil and coffee had a higher amount of unsaturated fatty acids (UFA) and a lower amount of saturated fatty acids (SFA) than the untreated cheese. The proportions of long-chain UFA, such as the C18:2n6c (Omega 6) and the C18:3n3 (Omega 3), were higher in the treated cheese than those in the untreated cheese, as well as the C20:1, the C22:2 and the C24:1, which were not detected in the untreated cheese. Caffeine concentration in the treated cheese was 33.08 mg/L.

ARABICA COFFEE CULTIVARS IN DIFFERENT WATER REGIMES IN THE CENTRAL CERRADO REGION

Phenotypic characterization of coffee cultivars under an irrigation system, as well as adaptability to controlled water stress, aiming at flowering uniformity, high yield and grain quality, plays an important role in coffee production in the cerrado areas. A field trial was carried out aiming to evaluate the agronomic performance of arabica coffee cultivars under different water regimes, using center pivot irrigation: irrigation throughout the year (WR1); suspended at the end of June for 40 days until leaf water potential reached -1.5 MPa (WR2); suspended at the end of June for 70 days until leaf water potential reached -2.3 MPa (WR3); suspended at the end of June for 100 days until leaf water potential reached -3.4 MPa (WR4); and a non-irrigated regime (WR5). The following traits were analyzed: plant height, stem diameter, canopy projection, number of plagiotropic branches, coffee grain yield, percentage of fruit in the cherry stage, and sieve retention percentages. Higher yield, plant growth, and percentage of fruit in the cherry stage are observed in the water regime with seventy days of controlled water stress (WR3). The Obatã IAC 1669-20 cultivar exhibits high yield and plant growth values in an irrigated system, and Catuaí Amarelo IAC 86 stands out in the non-irrigated system. For these genotypes, the coffee grain yield is most highly correlated with number of reproductive branches.

Mathematical modelling of the steam stripping of aroma from roast and ground coffee

Instant coffee manufacture involves the aqueous extraction of soluble coffee components followed by drying to form a soluble powder. A challenge that arises from the process is the loss of volatile aroma compounds during evaporative drying. One method of retaining aroma is to first steam strip the volatiles from the coffee and add them back to a concentrated coffee solution just before the final drying stage. Understanding the impact of process conditions on the aroma content of the stripped solution offers engineers the ability to target desirable compounds and maximise their yield. This paper presents a multiscale model for aroma extraction that describes: (i) release from the matrix, (ii) diffusion through the coffee grain, (iii) transfer into water and steam, and (iv) advection through the stripping column. Results reveal how aroma physiochemistry determines the limiting kinetics at industrial extraction conditions. The interaction with the soluble matrix can also inhibit extraction, but this effect varies for the different aromas studied.

Evaluation of the Energy Density for Burning Disaggregated and Pelletized Coffee Husks.

Coffee husks represent about 12 wt % of coffee grains, generating a significant impact on the environment because of its inadequate disposal. In Colombia, this waste presents an energy resource opportunity equivalent to over 49,106 TJ per year. However, several challenges related to this type of biomass, such as the moisture content, the irregular shapes, and the low bulk density, make its use difficult in current burners. Thus, in this paper, the combustion of coffee husk pellets was studied in detail to design a high-efficiency burner to produce energy for coffee drying. The pellets were prepared in a pelletizer with 15% moisture and 20% yield and burned in a bench-scale lateral reactor to determine the energy density. It was found that the combustion properties of coffee husk depend on the specifics of the pelleting process. The energy density values were Iv = 0.789 MW/m3 and Ig = 0.007 MW/m2, which could be used to design the combustion chamber for coffee husk burning.

Capacidad depredadora de Cathartus quadricollis y Ahasverus advena (Coleoptera: Silvanidae) sobre Hypothenemus hampei (Coleoptera: Curculionidae) en laboratorio

La broca del café ocasiona daños económicos y deterioro en la calidad del grano. Se reproduce en los frutos que quedan después de las cosechas. En Colombia se han reportado depredadores nativos que atacan a esta plaga, entre ellos los coleópteros Ahasverus advena y Cathartus quadricollis. Esta investigación tuvo como objetivo evaluar la depredación de estas dos especies sobre la broca, en condiciones de laboratorio en Cenicafé, Manizales. En cuatro bioensayos independientes se liberaron los depredadores, tanto adultos como larvas, en proporciones de 1, 3 y 5 por grano infestado. Se determinó la disminución de los estados de la broca al interior de los frutos después de establecidos los tratamientos. Las unidades experimentales estuvieron conformadas por 10 almendras de café infestadas con broca por 18 días, con tres orificios de entrada, en un recipiente de vidrio donde se aplicaron los cuatro tratamientos bajo un diseño completamente al azar con diez repeticiones. Se utilizó un testigo absoluto para cada bioensayo. Se encontró que tanto los adultos como las larvas de A. advena disminuyeron significativamente la broca entre 63,2 % y 42,3 % menos con respecto al testigo, siendo mayor la capacidad depredadora cuando se utilizaron tres individuos por grano brocado. Igualmente, C. quadricollis disminuyó de broca hasta 46,2 % y 69 % cuando se liberaron tres adultos y cinco larvas por grano, respectivamente.

Effect of drying and mechanical pre-drying previous to storage in the quality of coffee grain (Coffea arabica L.)

The aim of this study was to evaluate the effect of drying and pre-drying conditions of samples of parchment coffee stored during 6 months under controlled conditions of relative humidity of 70% and temperature of 25°C quantifying the Electrical Conductivity (EC), Potassium Leaching (KL) and Fatty Acidity (FA) of the grain. The coffee drying consisted on combined processes using air temperatures of 50°C and 60°C and two periods of 4 and 8 hours in the mechanical pre-drying and subsequently taken to commercial moisture content under patio drying, and two control treatments consisting of complete mechanical drying and complete solar drying. The results of the tests showed the following values: 6.35 - 16.34 Sm cm-1 / g DM (EC), 2.0 - 4.45ppm / g DM (KL) and 0.76 - 1.57mL KOH / 100g MS (FA), where the statistical analysis shows that there is no effect of the drying type on the studied variables. However, the highest accumulated averages in the storage time were observed for the complete mechanical drying. The values did not show deterioration of the cellular structure attributed to the frame of reference of drying with high temperature or prolonged storage. The tests of Electrical Conductivity (EC) and Fatty Acidity (FA) shows sensitivity to the storage time while the Potassium Leaching (KL) test did not constitute an indicator of grain deterioration attributable to thermomechanical stress or storage time.

Caracterización química de una nueva variedad de Coffea arabica L. cosechado en 2016 en Huatusco, Veracruz-México

The varieties of coffee resistant to pests and diseases as an alternative use to maintain their production, must first adapt to the soil conditions of the cultivated regions, present an adequate production yield (kg/ha) and contain quality chemical markers, which will impact on the aromatic and sensory profile in your drink. The objective of this work was to characterize chemically the hybrid variety of coffee “Millennium” (H10®), introduced in 2015 in Veracruz, Mexico and compare it with the variety “Typica” (VT). The content of lipids, protein, caffeine, sucrose and 5-O-caffeoyl-quinic acid (5-CQA) was studied in green coffee grains, by classical and chromatographic methods (HPLC); and the volatile fraction in green and roasted grains, was studied by the coupling technique of: HS-SPME-GC-MS and by the direct incidence of plasma ray on coffee beans (UPLC-ESI-MS/MS). The dry matter values of caffeine (0.8g/100g) and sucrose (6.6/100g) in green beans were similar in H10® to those in VT. The content of lipids and 5-CQA, of H10®, showed a significant positive difference of +6.1g and +0.1g per 100g respectively and a significantly lower protein content of -2.5g/100g with respect to the VT. Of a total of 24 volatile organic compounds identified by HS-SPME-GC-SM in roasted samples, only 2-methylpropanal, 3-acetyl-1-methylpyrrole and myrcene, were present in the H10® variety with respect to VT. The study by UPLC-ESI-MS/MS, showed in green and roasted beans a total of 87 more intense ions, where in green coffee, the H10® variety was characterized by 19 ions and the VT by an ion. For roasted coffee, 6 bins between 85.97 and 290.87m/z, characterized the volatile fraction of H10®, while 7 bins between 80.02 and 470.21m/z characterized the volatile fraction of the VT.

YIELD, QUALITY AND WATER CONSUMPTION OF CONILON COFFEE UNDER IRRIGATED AND DRYLAND MANAGEMENTS

In this study the goal was to make an assessment and comparison of the yield, quality and water consumed by the Conilon coffee plants under irrigated and dryland types of cultivation, from seedlings raised in different containers and under varying shading levels. The experiment which extended from December 2007 to April 2012 was performed at the IFES, Alegre-ES Campus and involved the study of a total of four crops. The findings showed that the irrigated plants had 162% higher yield on average than did the rainfed plants. For the irrigated plants, the yield indices achieved were 4.5 kg of coffee of the planted / benefited area; 1.9 kg of coconut / beneficiated coffee and 5.6 balms of 80 L sc-¹; whereas, for the rainfed plants, the values recorded were 8.2 kg of coffee from the benefited field; 3.1 kg of coconut / beneficiated coffee and 12 balloons of 80 L sc-¹. The Conilon coffee grains harvested from the irrigated plants were superior in quality to those from the rainfed plants. For the irrigated plants, the water consumed on average was 7.9 m 3 per plant, while for the rainfall-dependent crop, it was 4.95 m 3 . For the irrigated and rainfed plants the relations between the water consumption / kg of the beneficiated coffee was 8.8 m 3 and 30.3 m 3 , respectively. The type of container and levels of shading exerted no influence on the Conilon coffee with respect to productivity, yield and quality.

Thermal Analysis of Coffee Hulls and their Effect on the Drying Process in Conventional Ovens

Background/Objectives: This article includes some of the most relevant experimental results related to the thermal properties of coffee hulls taken from samples of a Colombian coffee variety Castilla. Methods: Coffee hull samples were analyzed using IR, DSC, TGA and DTGA. Analytical thermal experiments described its thermal behavior when it was heated at 5°C/min from room temperature to about 900°C. Furthermore, we include some drying curves and analyze the observed delay effect of the hull presence on the coffee drying process. Findings: Some of the main thermal transitions where observed in the range of 50-300°C. The IR test showed that its main composition was cellulose. Such delay was related to the hull composition. The diffusion coefficients of water in coffee grains with hull, without its hull, and of hull alone, are also reported. Applications: This work provides important information to understand in a better form some thermal characteristics and inference in drying process of coffee grains hull of variety Castilla, original from Colombia northeast region. Keywords: Coffee Grains Drying, Coffee Hull, Thermal Analysis, DSC, TGA, IR

MONITOREO DEL TOSTADO DE CAF´E USANDO LA TRANSFORMADA DE FOURIER 2D

The roasting stage during coffee processing is a critical determinant of coffee sensorial features. However, direct monitoring methods are currently not available, which difficult its standardization. In this work, image analysis of the surface of coffee grains is proposed as an indirect monitoring tool of the coffee roasting. Images of coffee grains were obtained from two types of roasting units and processed using 2D Fourier Transform. The results allowed to the identification of a direct correlation between the degree of roasting coffee with scaling exponents obtained fromthe image analysis.

Toward a New Brewing Control Chart for the 21st Century.

This paper describes new results from a base model of brewing from a bed of packed coffee grains. The model solves for the diffusion of soluble species out of a distribution of particles into the flow through the bed pore space. It requires a limited set of input parameters. It gives a simple picture of the basic physics of coffee brewing and sets out a set of reduced variables for this process. The importance of bed extraction efficiency is elucidated. A coffee brewing control chart has been widely used to describe the region of ideal coffee brewing for some 50 years. A new chart is needed, however, one that connects actual brewing conditions (weight, flow rate, brew time, grind, etc.) to the yield and strength of brews. The paper shows a new approach to brewing control charts, including brew time and bed extraction efficiency as control parameters. Using the base model, an example chart will be given for a particular grind ratio of coarse to fine particles, and an "espresso regime" will be picked out. From such a chart yield, volume and strength of a brew can be read off at will.

Fatty Acids Profile of Coffea arabica L. Resistant to Leaf Rust Grown in Two Environments of Minas Gerais, Brazil

The quality of the coffee drink is defined by its sensorial attributes which are developed through the chemical predecessors found on raw grains. Due to this relation, this present work had a goal evaluating the sensorial characteristics of resistant coffee cultivars to leaf rust for the production of specialty coffee and correlate them with the profile of fatty acids present on raw grains, enabling the distinction of cultivars in two environments of Minas Gerais. For this purpose, seven cultivars of Coffea arabica resistance to leaf rust were evaluated and two susceptible cultivars, in two growing environments: Lavras, in the South of Minas Gerais and Patrocínio, in the Cerrado of Minas Gerais. The C16:0, C16:1, C18:0, C18:1, C18:2 w-6, C18:3 w-3 fatty acids common in coffee grains, were identified in the cultivars. The presence of an acid uncommon in coffee grains, the gamma linolenic acid (C18:3 w-6, GLA) was also detected. The palmitic and alpha linolenic fatty acids presented correlation with the sensorial quality of the drink. The linoleic, palmitic, alpha linolenic and gamma linolenic fatty acids were capable to differentiate the Patrocinio and Lavras environments. The profile of the fatty acids permitted differentiate the leaf rust resistant cultivars, the environments as also the interaction between these two matters related to the sensorial quality.

Comparison of Attenuated Total Reflectance Mid-Infrared, Near Infrared, and 1H-Nuclear Magnetic Resonance Spectroscopies for the Determination of Coffee's Geographical Origin.

The sensorial properties of Colombian coffee are renowned worldwide, which is reflected in its market value. This raises the threat of fraud by adulteration using coffee grains from other countries, thus creating a demand for robust and cost-effective methods for the determination of geographical origin of coffee samples. Spectroscopic techniques such as Nuclear Magnetic Resonance (NMR), near infrared (NIR), and mid-infrared (mIR) have arisen as strong candidates for the task. Although a body of work exists that reports on their individual performances, a faithful comparison has not been established yet. We evaluated the performance of 1H-NMR, Attenuated Total Reflectance mIR (ATR-mIR), and NIR applied to fraud detection in Colombian coffee. For each technique, we built classification models for discrimination by species (C. arabica versus C. canephora (or robusta)) and by origin (Colombia versus other C. arabica) using a common set of coffee samples. All techniques successfully discriminated samples by species, as expected. Regarding origin determination, ATR-mIR and 1H-NMR showed comparable capacity to discriminate Colombian coffee samples, while NIR fell short by comparison. In conclusion, ATR-mIR, a less common technique in the field of coffee adulteration and fraud detection, emerges as a strong candidate, faster and with lower cost compared to 1H-NMR and more discriminating compared to NIR.

Development of a Rapid Method for the Determination of Caffeine in Coffee Grains by GC-FID-A Fully Validated Approach.

A simple method for the determination of caffeine in coffee grains by GC-FID (Gas Chromatography-Flame Ionisation Detector) is presented in the current work. The method was fully validated according to ISO (International Organization for Standardization) 17025 requirements and European Commission regulations. The accuracy, as provided by recovery experiments, was higher than 93%, and the precision, as provided by the (%) relative standard deviation under reproducibility conditions, was lower than 5%. A vast number of independent parameters that lead in the increase of uncertainty of methods were investigated. The analysis was performed without use of an internal standard, which was proven to be reliable according to several validation methods. The method was applied in real samples, and possible health claims were investigated.

Proteomic analysis of coffee grains exposed to different drying process.

Many biochemical events occur inside grains during post-harvest processes. Several methods have been developed to relate the chemical composition of the coffee grain to the beverage quality, including identification of possible molecular markers for flavor characterizing. This study was aimed at evaluating the changes in the proteomic profile of pulped and natural C. arabica grains dried in a yard or dryer at 60°C. It was observed that fruits dried in a dryer at 60°C showed an altered proteomic profile, with a reduction in the most abundant proteins compared to those yard-dried grains. Among the identified proteins, those involved in the metabolism of sugars and stress response were highlighted. Results have shown that post-harvest processes that impact coffee quality are related to changes in protein abundance, indicating that proteomic analysis may be effective in the identification of biochemical changes in coffee grains subjected to different post-harvest processes.

Polos de desarrollo económico en el departamento de Usulután en El Salvador

<p>En la presente investigación se expone el potencial nacional de los recursos renovables en microrregiones, dentro de la bahía Jiquilisco y la Sierra Tecapa Chinameca del departamento de Usulután en El Salvador. La acumulación de investigación biotecnológica del Ministerio de Agricultura, el Centro de Investigación de Café, el Consejo de Salvadoreño de Café, el Centro Nacional de investigación Agrícola y la Escuela Nacional de Agricultura, muestra la existencia de recursos naturales renovables y la capacidad tecnológica necesaria para su explotación de forma responsable, en donde las dislocaciones de pesca, coco, camarón, hortalizas, micro ganadería, cobran especial importancia como polos potenciales de desarrollo económico, incluyéndose la producción e industrialización del café en pequeños beneficios.</p><p>Realidad y Reflexión Año 15, N° 42, 2015; 117-138</p>

Development and performance evaluation of moisture range system for green coffee grains

AbstractThe system presented estimates moisture in green coffee during drying process using two methods, which were capacitive sensors and mechanical load detection, to estimate it. Results show it is possible to determine coffee grains moisture from 40 to 10% humidity range, either by dielectric measurements, with a developed sensor, or dryer mechanical load, making it possible to get better storage conditions for coffee beans.