Ultrastructural analysis of drying damage in parchment Arabica coffee endosperm cells

Borém, Flávio Meira; Marques, Eduardo Antônio Gomes; Alves, Eduardo

doi:10.1016/j.biosystemseng.2007.09.027

Cited by 46 publications

(23 citation statements)

References 3 publications

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“…However, the lowest variation among the products was at 55°C, indicating that a rupture of the parchment probably occurred during the drying process at this T. This rupture led to a similar behavior of the products. This trend was also observed by Borém et al (2008), who reported that above 50°C of drying T, cellular disorganization of the parchment occurs.…”

Section: Discussionsupporting

confidence: 63%

“…Consequently, these models must be studied for each product and air condition to determine which model is best for predicting the EMC of the product in certain air conditions. Recent research has studied parchment alteration during drying (Borém et al, 2008), heat and mass transfer during drying (Hernández-Díaz et al, 2008), the thermal properties (Chandrasekar and Viswanathan, 1999;Pérez-Alegría and Ciro-Velásquez, 2001) and the physical properties of coffee grains (Chandrasekar and Viswanathan, 1999). No previous research has investigated the effects of the parchment on the drying process and the physical properties of coffee grains.…”

Section: Introductionmentioning

confidence: 99%

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Hygroscopic equilibrium and physical properties evaluation affected by parchment presence of coffee grain

Corrêa

Oliveira

Rodrigues

et al. 2010

Span. j. agric. res.

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Physical properties are essential for the development of silos, transport calculations, separation and classification of grain and seeds. The present work evaluates the influence of the parchment on the drying and physical properties of coffee grains. The true density (ρ t ), bulk density (ρ b ) and porosity (ε) were evaluated for coffee grains (cv. Catuaí Amarelo) with and without parchment. Four mathematical models (Chung-Pfost, GAB, Modified Henderson and Oswin) were fitted to the experimental data to acquire desorption isotherms. The drying treatment was conducted in a factorial scheme with four levels of temperature (20, 35, 45 and 55°C) and five levels of relative humidity of the drying air (30, 40, 50, 60 and 80%) in a completely randomized design. The respective equilibrium moisture contents of the coffee grains were measured for each drying condition. No differences were observed among the products on the desorption isotherms. The pulped coffee with parchment (PP) had higher ε values than the pulped coffee without parchment (PR). The true density was higher for the PP coffee, but as the moisture content (X) increased, the true densities became more similar for the two samples. The ρ b was higher for the PP coffee than for the PR coffee. Higher initial and final values of ρ b were found for the PR and PP coffee, respectively. The Guggenheim-Anderson-de Bôer model was the model that best represented the experimental data for the drying process.Additional key words: density, drying, porosity, sorption isotherms. ResumenEvaluación del equilibrio higroscópico y de las propiedades físicas afectadas por la presencia de pergamino en los granos de café Las propiedades físicas son esenciales para el desarrollo de los silos y cálculos de transporte, separación y clasificación de granos y semillas. El presente trabajo evaluó la influencia del pergamino en el secado y en las propiedades físicas de los granos de café. Se evaluaron la densidad real (ρ t ), la densidad aparente (ρ b ) y la porosidad (ε) para los granos de café (cv. Catuaí Amarelo) con y sin pergamino. Se ajustaron cuatro modelos matemáticos (Chung-Pfost, GAB, Henderson Modificado y Oswin) a los datos experimentales para obtener isotermas de desorción. El tratamiento de secado se realizó en un esquema factorial con cuatro niveles de temperatura (20, 35, 45 y 55°C) y cinco niveles de humedad relativa del aire de secado (30, 40, 50, 60 y 80%) en un diseño completamente al azar. Se midió el contenido de humedad de equilibrio de los granos de café para cada condición de secado. No se observaron diferencias entre los productos en las isotermas de desorción. El café despulpado con pergamino (PP) presentó mayores valores de ε que el café despulpado sin pergamino (PR). La densidad real fue mayor para el café PP, pero según se incrementó el contenido de humedad (X), la densidad real se hizo más similar para ambas muestras. El ρ b fue mayor para el café PP que para el café PR. Los valores más altos iniciales y finales de ρ b se observaron en el café PR ...

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Section: Discussionsupporting

confidence: 63%

Section: Introductionmentioning

confidence: 99%

Hygroscopic equilibrium and physical properties evaluation affected by parchment presence of coffee grain

Corrêa

Oliveira

Rodrigues

et al. 2010

Span. j. agric. res.

View full text Add to dashboard Cite

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“…Recentemente têm sido realizados inúmeros trabalhos com o objetivo de identificar as características de diversos produtos agrícolas durante a secagem como: trigo (Sun e Woods, 1994;Goneli et al, 2007), feijão , arroz em casca (Basunia e Abe, 2001;Resende et al, 2005), uva (Ramos et al, 2004;Ramos et al, 2005), pimenta (Kaymak-Ertekin, 2002;Akpinar et al, 2003), pêra (Lahsasni et al, 2004), trigo parbolizado (Mohapatra e Rao, 2005), tomate (Doymaz, 2007a), café em coco (Corrêa et al, 2006;Borém et al, 2008;Resende et al, 2009) e abóbora (Doymaz, 2007b), dentre outros.…”

Section: Introductionunclassified

Cinética da secagem de clones de café (Coffea canephora Pierre) em terreiro de chão batido

et al. 2010

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RESUMOObjetivou-se com o presente trabalho estudar a cinética da secagem de quatro clones de café da espécie Coffea canephora submetidos à secagem em terreiro de chão batido, bem como ajustar diferentes modelos matemáticos aos valores experimentais selecionando aquele que melhor representa o fenômeno em estudo. Kinetics of coffee berry clones drying (Coffea canephora Pierre) in ground pavement ABSTRACTThe objective of this work was to study the drying kinetics of four coffee berry clones Coffea canephora species dried in ground pavement and to fit different mathematical models to different experimental data selecting the one that best represents the phenomenon. Have been used coffee berry of clones: Cpafro 194, Cpafro 193, Cpafro 167 and Cpafro 180, harvested at moisture content of 1.20; 1.32; 1.51 e 1.46 (decimal d.b.), respectively. The drying continued in ground pavement until achieved the moisture content of 0.13 (decimal d.b.). Ten mathematical models cited in the literature were fitted to the experimental data in order to represent the drying process. Based on the statistical parameters it can be concluded that the Verma, Dois Termos and Aproximação da Difusão models represent well the drying of four coffee berry clones, and beyond these for the clone Cpafro 167, the Thompson, Page, Newton, Logarítmico, Henderson e Pabis and Exponencial de Dois Termos models also shown in satisfactory description of the phenomenon; the drying time in ground pavement of coffee berry clones Cpafro 194, Cpafro 193, Cpafro 167 and Cpafro 180, until the moisture content of 0.13 (decimal d.b.) was 189.5 hours.

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“…Nonetheless, numerous thermal and physical mechanisms have been proposed to describe the transport of water in hygroscopic porous capillary products (Brooke et al, 1992). However, recent theories suggest that at a particular stage of the drying, water movement is largely determined by liquid diffusion (Borém, Marques, & Alves, 2008). Liquid diffusion should be facilitated by both a temperature increase and the removal of physical barriers, as occurs as a result of the coffee pulping process in comparison to the drying of natural coffee.…”

Section: Resultsmentioning

confidence: 99%

<b>Physiological and sensorial quality of Arabica coffee subjected to different temperatures and drying airflows

et al. 2017

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ABSTRACT. The objective of this study was to evaluate the correlation between a group of physiological variables (electrical conductivity, potassium leaching, and germination percentage) and a group of drying kinetics variables (drying time and drying rate) in addition to verifying the relation between drying kinetics variables and coffee quality as a function of processing type, temperature, and drying airflow. Coffee drying was conducted in a fixed-layer dryer at two temperatures and two airflows. After drying, an evaluation of the physiological and sensorial quality was conducted. Based on the results obtained, the following conclusions were drawn: coffee that is processed via a dry method is more sensitive to mechanical drying with heated air than coffee processed via a wet method, resulting in poor physiological performance; airflow does not interfere with the physiological quality of pulped and natural coffees; a temperature increase from 40 to 45°C resulted in a decrease in the physiological quality only for pulped coffee; and an increase in the drying rate as a result of an increase in the drying temperature to 40°C had a negative effect on the sensorial quality of pulped coffee.Keywords: drying kinetics, processing, drying rate.Qualidade fisiológica e sensorial do café arábica submetido a diferentes temperaturas e fluxos de ar de secagem RESUMO. Este trabalho foi realizado com o objetivo de avaliar a correlação entre um grupo de variáveis fisiológicas (condutividade elétrica, lixiviação de potássio e porcentagem de germinação) e um grupo de variáveis de cinética de secagem (tempo e taxa de secagem), bem como verificar a relação entre as variáveis de cinética de secagem e a qualidade sensorial do café, em função do tipo de processamento, da temperatura e do fluxo de ar de secagem. A secagem do café foi realizada em secador de leito fixo com duas temperaturas e dois fluxos de ar. Após a secagem, foi avaliada a qualidade fisiológica e sensorial. A partir dos resultados obtidos, conclui-se que: o café processado via seca é mais sensível à secagem mecânica com ar aquecido do que o processado via úmida, apresentando pior desempenho fisiológico; o fluxo de ar não interfere na qualidade fisiológica do café despolpado e natural; a elevação da temperatura de 40 para 45°C resultou em queda da qualidade fisiológica apenas para o café despolpado e a elevação da taxa de secagem, por meio da elevação do fluxo de ar de secagem, para a temperatura de 40°C teve efeito negativo na qualidade sensorial do café despolpado.Palavras-chave: cinética de secagem, processamento, taxa de secagem.

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Ultrastructural analysis of drying damage in parchment Arabica coffee endosperm cells

Cited by 46 publications

References 3 publications

Hygroscopic equilibrium and physical properties evaluation affected by parchment presence of coffee grain

Hygroscopic equilibrium and physical properties evaluation affected by parchment presence of coffee grain

Cinética da secagem de clones de café (Coffea canephora Pierre) em terreiro de chão batido

<b>Physiological and sensorial quality of Arabica coffee subjected to different temperatures and drying airflows

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