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.

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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.

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...