Kinetics of mass loss of arabica coffee during roasting process

Roasting is one of the most complex coffee processing steps due to simultaneous transfers of heat and mass. During this process, beans lose mass because of fast physical and chemical changes that will set color and flavor of the commercial coffee beverage. Therefore, we aimed at assessing the kinetics of mass loss in commercially roasted coffee beans according to heating throughout the processing. For that, we used samples of 350-g Arabica coffee processed grains with water content of 0.1217 kga kg-1, in addition to a continuous roaster with firing gas. The roaster had initial temperatures of 285, 325, 345 and 380 °C, decreasing during the process up to 255, 285, 305 and 335 °C respectively. Mass loss was calculated by the difference between grain weight before and after roasting. We observed a linear variation directly dependent on roaster temperature. For each temperature during the process was obtained a constant mass loss rate, which was reported by the Arrhenius model with r2 above 0.98. In a roaster in non-isothermal conditions, the required activation energy to start the mass loss in a commercial coffee roasting index was 52.27 kJ mol -1.A torrefação é uma das etapas mais complexa do processamento do café devido à transferência simultânea de calor e massa, em que os grãos perdem massa devido à rapidez das mudanças físicas e químicas, necessárias para produzir a cor e o aroma do café comercial. Assim, objetivou-se com este trabalho determinar a cinética da perda de massa dos grãos de café torrados comercialmente em função da temperatura do processo. Foram usadas amostras de 350 g de grãos beneficiados de café arábica com teor de água de 0,1217 kga kg-1 . Usou-se um torrador com queima de gás constante e temperaturas iniciais de 285; 325; 345 e 380 °C, que diminuíram durante a operação até equilibrar-se em 255; 285; 305 e 335 °C, respectivamente. A perda de massa foi calculada a partir do peso dos grãos antes e depois da torração, sendo observada uma variação linear dependente diretamente da temperatura do torrador. Para cada temperatura do processo, foi obtida uma taxa constante de perda de massa, que foi relacionada pelo modelo de Arrhenius com r2 acima de 0,98. Em condições não isotérmicas do torrador, a energia de ativação necessária para iniciar a perda de massa, em índices de torração comercial do café, foi 52,27 kJ mol-1 .Universidad de Costa Rica/[]/UCR/Costa RicaConselho Nacional de Desenvolvimento Científico e Tecnológico/[]/CNPq/BrasilCoordenação de Aperfeiçoamento de Pessoal de Nível Superior/[]/CAPES/ BrasilFundação de Amparo à Pesquisa do Estado de Minas Gerais/[]/FAPEMIG/BrasilUCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Agroalimentarias::Centro para Investigaciones en Granos y Semillas (CIGRAS

Conservação de café torrado e moído durante o armazenamento. Parte 2: Massa específica e porosidade

The determination of physical properties is an important factor in the design of machinery and the scaling of post-harvest operations. The present study evaluates the influence of the level of roasting and the size of grinding on the physical properties of coffee during storage. The following physical properties were evaluated: true and bulk density, and intergranular porosity. Raw coffee beans (Coffea canephora and Coffea arabica), hulled and dried, were roasted to two different levels: medium light (SCAA#65) and moderately dark (SCAA#45). The beans were then grinded into three different sizes: fine (0.59 mm), medium (0.84 mm) and coarse (1.19 mm). An additional coffee lot was kept whole. Following grinding, samples were stored at two different temperatures (10 and 30 ºC) and analyzed after five different storage durations (0, 30, 60, 120 and 180 days). The medium light roast had higher values for each of the measured physical properties. Finely ground samples had higher true and bulk densities, and porosities. It is concluded that the size of grinding, level of roasting and duration of storage significantly affect the physical properties of coffee.A determinação das propriedades físicas é fator importante na formulação de projetos de maquinários e dimensionamento de operações pós-colheita. De forma a permitir o dimensionamento correto e o uso desses maquinários, objetivou-se avaliar e determinar, durante o armazenamento, as propriedades físicas: massa específica unitária e aparente e porosidade intergranular, além de avaliar a influência dos níveis de torrefação e moagem sobre essas propriedades. Grãos de café cru (Coffea canephora e Coffea arabica) foram utilizados, descascados e secados e só então torrados em dois níveis: média clara (SCAA#65) e moderadamente escura (SCAA#45). Os grãos foram moídos em três granulometrias: fina (0,59 mm), média (0,84 mm) e grossa (1,19 mm), além do lote de café inteiro. Realizada a moagem as amostras foram armazenadas em duas temperaturas (10 e 30 ºC) e analisadas em cinco tempos distintos de armazenamento (0, 30, 60, 120 e 180 dias). A torra média clara permitiu maiores valores das propriedades físicas; já as amostras de granulometria fina apresentaram aumento das massas específica unitária e aparente e porosidade. Conclui-se que a granulometria, o nível de torrefação e o tempo de armazenamento, afetaram as propriedades físicas do café.National Council for Scientificand Technological Development/[CNPq nº 14/2012]/CNPq/BrasilUCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Agroalimentarias::Centro para Investigaciones en Granos y Semillas (CIGRAS

Epidemiological trends of HIV/HCV coinfection in Spain, 2015-2019

Altres ajuts: Spanish AIDS Research Network; European Funding for Regional Development (FEDER).Objectives: We assessed the prevalence of anti-hepatitis C virus (HCV) antibodies and active HCV infection (HCV-RNA-positive) in people living with HIV (PLWH) in Spain in 2019 and compared the results with those of four similar studies performed during 2015-2018. Methods: The study was performed in 41 centres. Sample size was estimated for an accuracy of 1%. Patients were selected by random sampling with proportional allocation. Results: The reference population comprised 41 973 PLWH, and the sample size was 1325. HCV serostatus was known in 1316 PLWH (99.3%), of whom 376 (28.6%) were HCV antibody (Ab)-positive (78.7% were prior injection drug users); 29 were HCV-RNA-positive (2.2%). Of the 29 HCV-RNA-positive PLWH, infection was chronic in 24, it was acute/recent in one, and it was of unknown duration in four. Cirrhosis was present in 71 (5.4%) PLWH overall, three (10.3%) HCV-RNA-positive patients and 68 (23.4%) of those who cleared HCV after anti-HCV therapy (p = 0.04). The prevalence of anti-HCV antibodies decreased steadily from 37.7% in 2015 to 28.6% in 2019 (p < 0.001); the prevalence of active HCV infection decreased from 22.1% in 2015 to 2.2% in 2019 (p < 0.001). Uptake of anti-HCV treatment increased from 53.9% in 2015 to 95.0% in 2019 (p < 0.001). Conclusions: In Spain, the prevalence of active HCV infection among PLWH at the end of 2019 was 2.2%, i.e. 90.0% lower than in 2015. Increased exposure to DAAs was probably the main reason for this sharp reduction. Despite the high coverage of treatment with direct-acting antiviral agents, HCV-related cirrhosis remains significant in this population

Recolección de tejidos biológicos para análisis genéticos

La información genética es una fuente de conocimiento fundamental para la gestión integral de la biodiversidad. Sin embargo, la baja disponibilidad de tejidos biológicos bien recolectados y preservados limita la integración de esta información en la toma de decisiones ambientales en países megadiversos, como Colombia. Aquí se presentan infográficamente las mejores prácticas de recolección de tejidos para una gran variedad de grupos biológicos, ofreciendo alternativas de muestreo que son prácticas bajo diferentes contextos. Cada capítulo es de la autoría de investigadores con experiencia en la recolección de tejidos en sus grupos de estudio y fue revisado científicamente por al menos dos evaluadores externos. Esta publicación ofrece la instrucción necesaria para recolectar muestras ambientales y de tejidos de plantas, macroalgas, hongos, corales, esponjas, zooplancton, macroinvertebrados acuáticos, crustáceos, moluscos, insectos, peces cartilaginosos, mamíferos acuáticos, peces óseos, anfibios, reptiles, aves y mamíferos terrestres siguiendo buenas prácticas de marcado, recolección y preservación. En la mayoría de estos grupos se presentan alternativas de muestreo no invasivo a partir de especímenes vivos y muestreo a partir de especímenes recién recolectados o depositados en colecciones biológicas, sin comprometer su integridad. Este trabajo hace parte de los alcances del programa Colombia BIO y constituye una síntesis de procedimientos útiles en campo y colecciones biológicas que busca incrementar la cantidad y calidad de las colecciones de tejidos y así fomentar la generación de información genética.Bogotá, D. C

Historia del Banco de la República 1923-2015

Para contar la historia de la banca central de un país se pueden elegir varios caminos. Es posible adoptar un enfoque de carácter biográfico, siguiendo sucesivamente las trayectorias vitales y laborales de los personajes más influyentes en el desarrollo cronológico y administrativo de la entidad; otro método común es hacer un seguimiento de las normas y regulaciones internas y externas que marcaron hitos en la actividad del banco central; también es posible concentrarse en las ideas y doctrinas económicas imperantes a lo largo de la historia de la institución y analizar cómo se reflejaron en el diseño de las políticas y las actuaciones de las autoridades. En el caso de la historia del Banco de la República que ahora presentamos se ha adoptado un enfoque ecléctico, con plena conciencia de que el lector encontrará como producto final un texto heterogéneo. Hemos querido que en este trabajo participara un conjunto muy destacado de economistas e historiadores colombianos, todos con vínculos académicos, personales o profesionales con el Banco, y un rango muy amplio de experiencias, enfoques e intereses. Algunos de los escritores invitados se han ocupado, de tiempo atrás, en la historia económica con un enfoque clásico de ciencia social; otros se han centrado principalmente en los estudios teóricos y econométricos, de manera que su aproximación a esta historia es quizá más descriptiva y puntual. (Tomado del prólogo del libro

Human immunodeficiency virus/hepatitis C virus coinfection in Spain : Prevalence and patient characteristics

The purpose of this study was to assess the prevalence of anti-hepatitis C virus (HCV) antibodies (Abs) and active HCV infection in human immunodeficiency virus (HIV)-infected (HIV+) patients in Spain in 2015. This was a cross-sectional study.Methods. The study was performed in 41 centers in 2015. Sample size was estimated for an accuracy of 2%, the number of patients from each hospital was determined by proportional allocation, and patients were selected using simple random sampling. The reference population was 35 791 patients, and the sample size was 1867 patients. Hepatitis C virus serostatus was known in 1843 patients (98.7%). Hepatitis C virus-Abs were detected in 695 patients (37.7%), in whom the main route of HIV acquisition was injection drug use (75.4%). Of these 695 patients, 402 had HCV RNA, 170 had had a sustained viral response (SVR) after anti-HCV therapy, and 102 cleared HCV spontaneously. Hepatitis C virus-ribonucleic acid results were unknown in 21 cases. Genotype distribution (known in 367 patients) was 1a in 143 patients (39.0%), 4 in 90 (24.5%) patients, 1b in 69 (18.8%) patients, 3 in 57 (15.5%) patients, 2 in 5 (1.4%) patients, and mixed in 3 (0.8%) patients. Liver cirrhosis was present in 93 patients (23.1%) with active HCV infection and in 39 (22.9%) patients with SVR after anti-HCV therapy. The prevalence of HCV-Abs and active HCV infection in HIV+ patients in Spain is 37.7% and 22.1%, respectively; these figures are significantly lower than those recorded in 2002 and 2009. The predominant genotypes in patients with active HCV infection were 1a and 4. A high percentage of patients had cirrhosis. Cirrhosis is also common in patients with SVR after anti-HCV therapy