Please cite this article as: Pramiu, P.V., Rizzi, R.L., do Prado, N.V., Coelho, S.R.M., Bassinello, P.Z., Numerical modeling of chickpea (Cicer arietinum) hydration: The effects of temperature and low pressure, Journal of Food Engineering (2015), doi: http://dx. AbstractChickpea is a leguminous that can be consumed both fresh and baked, and must be hydrated in both cases. The objective of this study was to discuss mathematical and numerical models, and also experimentally evaluate the process of water uptake in chickpea (Cicer arietinum) under different temperatures and pressures, determining the diffusion coefficient of water in the grains and the activation energy of the hydration process. The values for the diffusion coefficient ranged from 7.38 × 10 −11 to 5.21 × 10 −10 m 2 s −1 . The activation energy was determined at 36.040kJ mol −1 , the activation volume at −7.724 × 10 3 cm 3 mol −1 and the constant value was 2.185 ×10 −4 . By comparing the experimental results with those obtained from the analytical solution of the theoretical model, there was a satisfactory fit of the model to the experimental data, and the hydration curves were plotted. A good adjustment of the numerical model, the model of Abu-Ghannam and the Peleg model was made to the experimental data. The Arrhenius-Eyring type equation was used to explain the dependency of the diffusion coefficient with the temperature and pressure in the hydration process.

No abstract

RESUMO -O trabalho teve como objetivo modelar curvas de secagem do feijão-caupi (Vigna unguiculata (L.) Walp.) em diferentes temperaturas, determinar o coeficiente de difusão efetivo e a energia de ativação. Para isso, utilizou-se sementes de feijão-caupi, cultivar BRS guariba, colhidas manualmente, com teor de água de 21% (base úmida) e secas até o teor de água de 11% (base úmida). A secagem foi realizada em secador experimental sob temperaturas controladas de 30, 40 e 50 °C ± 1 °C e umidade relativa do ar de secagem entre 14 e 59%. Foram testados 12 modelos de regressão não-linear e para a seleção do melhor modelo considerou-se a significância do coeficiente de regressão pelo teste t, a magnitude do coeficiente de determinação ajustado (R²), o erro médio relativo (P) e o erro médio estimado (SE). Observou-se que o tempo de secagem para as sementes de feijão-caupi foi de 10,4, 5,6, e 2,1 h para as temperaturas de 30, 40 e 50 °C, respectivamente. Dentre a série testada, o modelo matemático de Midilli foi o que melhor se ajustou aos dados experimentais. O coeficiente de difusão aumenta com a elevação da temperatura, apresentando valores entre 5,047 x 10 -11 a 12,011 x 10 -11 m² s -1 para a faixa de temperatura de 30 a 50 °C. A relação entre o coeficiente de difusão efetivo e a temperatura de secagem podem ser descritas pela equação de Arrhenius, que apresenta uma energia de ativação de 35,04 kJ mol -1 para a difusão líquida no processo de secagem das sementes de feijão-caupi. Palavras-chave:Vigna unguiculata (L.) Walp. Curvas de secagem. Coeficiente de difusão. MODELING OF THE DRYING PROCESS THE SEEDS OF COWPEAABSTRACT -The study aimed to model the drying curves of cowpea beans (Vigna unguiculata (L.) Walp.) in different temperatures determine the coefficient of effective diffusion and the activation energy. For this, we used seeds of beans-cowpea cultivar BRS Guariba, harvested manually, with a water content of 21% (wet basis), dried until the water content 11% (wet basis). Drying was performed in the experimental dryer under controlled temperatures of 30, 40 and 50 °C ± 1 °C, and relative humidity of the air drying between 14 and 59%. 12 models of non-linear regression were tested and for selection the best model was considered to: the significance of the regression coefficient t test, the magnitude of the adjusted coefficient of determination (R²), the average relative error (P) and the estimated average error (SE). It was observed that the drying time for of the beans-cowpea seeds was 10,4 ; 5,6 ; and 2,1 h to the temperatures of 30, 40 and 50 °C, respectively; among the number tested, the mathematical model the Midilli was the best fit to experimental data. The coefficient of diffusion increases with temperature, with values between 5,047 x 10 -11 to 12,011 x 10 -11 m² s -1 for the temperature range from 30 to 50 °C. The relationship between the coefficient of diffusion effective and the drying temperature can be described by Arrhenius equation, which presents activation energy of 35,04 kJ mol -1 for spreadi...

RESUMOObjetivou-se, no presente trabalho, foi comparar alterações no tempo de cozimento e dureza dos grãos de duas variedades de feijão comum, durante o envelhecimento natural e o acelerado. O envelhecimento de um lote de cada variedade de feijão (Iapar 81variedade carioca e Iapar 44 -variedade preto) foi acelerado em estufa a 40ºC e 76% de UR% por 15, 30, 45, 60, 75 dias. Outro lote, das mesmas variedades, foi submetido ao envelhecimento em condições ambientais por três, seis, nove e doze meses. O lote-controle foi armazenado a 5 ºC. Após cada tempo de armazenagem, foram determinados os parâmetros de tempo de cozimento e dureza. Os grãos da variedade carioca apresentaram maiores tempos de cozimento em relação ao feijão preto, em ambos os sistemas de armazenagem. O feijão cozido da variedade carioca apresentou dureza maior que o feijão da variedade preto, tanto no envelhecimento acelerado quanto no envelhecimento natural. A dureza dos grãos cozidos e resfriados à temperatura ambiente foi superior a dos grãos resfriados a 60 ºC, visto que a temperatura influenciou nas medições, provavelmente pela maior retrogradação do amido à temperatura ambiente. O envelhecimento acelerado por vinte dias foi equivalente a um ano em condições naturais, em relação à dureza dos grãos.Termos para indexação: Armazenamento, pós-colheita, dureza, Phaseolus vulgaris L., tempo de cozimento. ABSTRACTThis experiment aimed to compare the changes of two varieties of common bean (Phaseolus vulgaris L.) concerning the cooking time and hardness data during their natural and accelerated aging processes. The aging of a parcel of each variety of bean (Iapar 81 -carioca variety and Iapar 44 -black variety) was performed in a 40ºC oven at 76% RH during 15, 30, 45, 60, and 75 days. Another parcel of the same varieties was submitted to the aging at room conditions during 3, 6, 9, and 12 months. The control lot was storage at 5 ºC. After each storage time, cooking time and hardness parameters were registered. Carioca variety showed the longest cooking times when compared to the black beans, in both storage systems. Cooked beans of carioca variety presented greater hardness than the black beans, not only in the accelerated aging but also in the natural aging. The hardness of the grains cooked and then cooled at room temperature was higher than the grains cooled at 60 ºC, since the temperature influenced the measurements, probably due to the greatest starch retrogradation at room temperature. At last, it may be concluded that twenty days of the accelerated aging was equivalent to one year in natural conditions, concerning the hardness of the grains.

Beans are popular as a protein-filled legume of high nutritional value, being one of the most planted species in the world. However, recent years have seen a decrease in the consumption of beans, owing to the time necessary to cook it domestically. Thus, it is being replaced in people’s diets by other foods. An alternative preparation that supplies modern consumers’ demands is industrially processed beans. This article aimed to provide a literature review on the processing of canned beans. Few recent studies have been performed in Brazil on this subject, as most studies have focused instead on the technological quality of dry bean grains processing. In this article industrial processing concepts and features, production unit operations, and canned beans quality standards will be discussed. These efforts are expected to contribute to the Brazilian beans production chain, and consequently to increase consumption of canned beans and the demand for industrial processing of beans in both the domestic market and future product exports.

ABSTRACT:The cassava leaf, waste generated in the harvest of the roots, is characterized by high content of protein, vitamins and minerals; however, its use is limited due to the high fiber content and antinutritional substances, which can be removed by obtaining protein concentrates. In this context, the objective of this study was to evaluate protein extraction processes, aiming the use of cassava leaves (Manihot esculenta Crantz) as an alternative protein. Four methods were tested: 1) Coagulation of Proteins by Lowering the Temperature, 2) Extraction by Isoelectric Precipitation, 3) Solubilization of Proteins and 4) Fermentation of Filter Leaf Juice. To obtain the concentrates, the use of fresh or dried leaves and extraction in one or two steps were also evaluated. The solubilization of proteins (method 3) showed a higher extraction yield; however, with concentrate of low quality. The fermentation of the juice (method 4) produced concentrates with higher quality and lower costs and the isoelectric precipitation (method 2) promoted the obtention of concentrates in less time, both with good prospects for use. The use of two extraction steps was not advantageous to the process and there was no difference between the use of fresh or dried leaf, and the use of fresh leaves is presented as a good option for the simplicity of the method.KEYWORDS: exploitation, agricultural waste, protein extraction. AVALIAÇÃO DE MÉTODOS DE EXTRAÇÃO DE PROTEÍNAS PARA OBTENÇÃO DE CONCENTRADO PROTÉICO DE FOLHAS DE MANDIOCARESUMO: A folha de mandioca, resíduo gerado na colheita das raízes, caracteriza-se pelo alto teor de proteínas, vitaminas e minerais, no entanto sua utilização é reduzida devido ao alto teor de fibras e substâncias antinutricionais que podem ser removidas durante obtenção de concentrados proteicos. Neste contexto, o objetivo do presente trabalho foi avaliar processos de extração de proteínas, visando ao aproveitamento das folhas de mandioca (Manihot esculenta Crantz) como alternativa proteica. Quatro métodos foram testados: 1) Coagulação de Proteínas por Abaixamento da Temperatura; 2) Extração por Precipitação Isoelétrica; 3) Solubilização das Proteínas; 4) Fermentação do Suco de Folhas Filtrado. Para a obtenção dos concentrados, avaliaram-se também a utilização de folhas frescas ou secas e a extração em uma ou duas etapas. A solubilização das proteínas (método 3) apresentou maior rendimento de extração, no entanto com concentrado de baixa qualidade. A fermentação do suco (método 4) produziu concentrados com mais qualidade e menores custos, e a precipitação isoelétrica (método 2) promoveu a obtenção de concentrados em menor tempo, sendo ambos com boas perspectivas de utilização. A utilização de duas etapas de extração não foi vantajosa ao processo e não houve diferença entre a utilização de folha seca ou fresca, sendo que a utilização de folhas frescas se apresenta como boa opção pela simplicidade do método. PALAVRAS-CHAVE:aproveitamento, resíduo agrícola, extração de proteínas.

Fixed-bed reactors have been considered promise alternatives for hydrogen production due to their simple construction and increase in the biomass retention. The purpose of this study was to investigate the biological production of hydrogen in anaerobic fixed-bed reactors with cassava starch wastewater used as substrate. Different support materials and arrangements of fixed-bed were used to evaluate the biological production of hydrogen in anaerobic continuous fixed-bed reactors, with cassava starch wastewater as substrate -recycled low-density polyethylene scraps, in packed bed (R1), recycled low-density polyethylene cylinders, in ordained bed (R3) and bamboo stems, in vertical arrangement (R2 and R4). In R1 the initial pH was adjusted for 6.0, with hydraulic retention time (HRT) of 4 h and organic loading rate (OLR) of 9.5 g.L -1 .d -1 . In R2 the initial pH was maintained in 4.5, with HRT of 4 h and OLR of 9.5 g. -1 ) were verified in the reactors with bamboo stems. In R4, the increase of OLR and the reduction of the initial pH contributed to the increase of butanol concentration in 1.8 times, diminishing the VHPR in 41.68%, yield in 63.95% and H2 in 37.6%, and indicating that the effect of pH is more pronounced with the increase of OLR, leading to the solventogenesis.

RESUMOEste trabalho tem, como objetivo, comparar concentrados protéicos de folhas de mandioca produzidos por diferentes métodos e propor procedimento de obtenção com maior rendimento, conteúdo e recuperação protéica, menor teor de taninos e cor mais clara. Concentrados protéicos foram obtidos por coagulação ácida (pH = 5), termocoagulação ácida (pH = 4 e a temepratura 85 e 50°C), coagulação em 30% etanol e termocoagulação (60°C). Foram determinados nos concentrados protéicos e nas folhas umidade, proteína, taninos, luminosidade e tonalidade cromática. Os concentrados de maior rendimento, conteúdo protéico e cor mais clara (termocoagulação ácida pH 4 a 50°C e coagulação 30% etanol) foram modificados. Após as modificações o concentrado obtido por coagulação em etanol apresentou 14,1% de recuperação protéica, luminosidade de 73,8 e tonalidade cromática de 99,8°, não diferindo do concentrado produzido por termocoagulação ácida. O conteúdo de taninos foi de 0,4% nos dois concentrados. Os procedimentos de termocoagulação ácida em pH 4 e 50°C e coagulação em 30% etanol modificados, são apropriados para a produção de concentrado protéico de folhas de mandioca com grande recuperação protéica e cor clara.Palavras-chave: ângulo hue, cor, imagens digitais, ingrediente alimentar, taninos Production and physicochemical characterization of cassava leaf protein concentrate ABSTRACTThe aim of this work was to compare cassava leaf protein concentrates produced by different methods and to propose procedures with large yield, protein content and recovery, small tannin content and light color. Protein concentrates were obtained by acid coagulation (pH = 5), acid thermo-coagulation (pH = 4 at 85 and 50°C), 30% ethanol coagulation and thermo-coagulation (60°C). Moisture, protein and tannin contents, and brightness and chromatic tonality were determined in protein concentrates and dried milled leaves. The concentrates with the largest yields, protein contents and the lightest colors (acid thermo-coagulation pH 4 and 50°C and 30% ethanol coagulation) were modified and, after the concentrate obtained by ethanol coagulation, presented a 14.1% protein recovery, a 73.8 brightness and 99.8°c hromatic tonality, not differing from the one produced by acid thermo-coagulation. The tannin content was 0.4% in both concentrates. The modified acid thermo-coagulation in pH 4 and 50°C and 30% ethanol coagulation procedures are correct for cassava leaf protein concentrate production with large protein recovery and light color.