Drying kinetics of crushed mass of ‘jambu’: Effective diffusivity and activation energy

Abstract

Palavras-chave: hortaliça secagem convectiva Acmella oleracea A B S T R A C TThe aim of this paper was to analyze the drying kinetics, test the Akaike information criterion (AIC) and Schwarz's Bayesian information criterion (BIC) in the selection of models, determine the effective diffusivity and activation energy of the crushed mass of 'jambu' leaves for different conditions of temperature and layer thicknesses. The experiment was carried out at the Food Laboratory of the Brazilian Agricultural Research Corporation (Embrapa) in Macapá-AP. Drying was carried out in air circulation oven with speed of 1.0 m s -1 at various temperatures (60, 70 and 80 ºC) and layer thicknesses (0.005 and 0.010 m). The experimental data were fitted to 11 mathematical models. Coefficient of determination (R²), mean relative error (P), mean estimated error (SE), Chi-square test (χ²), AIC and BIC were the selection criteria for the models. For the effective diffusivity, the Fick's diffusion model was used considering the flat plate geometry. It was found that Midilli and Logarithmic models showed the best fit to the experimental data of drying kinetics. Effective diffusion coefficient increases with increment in the thickness of the material and with the temperature elevation. Activation energy of the material was of 16.61 kJ mol -1 for the thickness of 0.005 m, and 16.97 kJ mol -1 for the thickness of 0.010 m. AIC and BIC can be additionally included to select models of drying.Cinética de secagem da massa triturada de jambu: Difusividade efetiva e energia de ativação R E S U M O Objetivou-se com o presente trabalho analisar a cinética de secagem, testar os critérios da informação de Akaike (AIC) e informação Bayesiano de Schwarz (BIC) para seleção dos modelos, determinar a difusividade efetiva e a energia de ativação de massa triturada de folhas de jambu para diferentes condições de temperatura e espessuras de camada. O experimento foi desenvolvido no Laboratório de Alimentos da Empresa Brasileira de Pesquisa Agropecuária (Embrapa), em Macapá -AP. A secagem foi realizada em estufa de circulação de ar com velocidade de 1,0 m s -1 em diferentes temperaturas (60, 70 e 80 ºC) e espessuras da camada (0,005 e 0,010 m). Aos dados experimentais foram ajustados onze modelos matemáticos. O coeficiente de determinação (R²), erro médio relativo (P), erro médio estimado (SE), teste de Qui-quadrado (χ²), AIC e BIC, foram os critérios de seleção dos modelos. Para a difusividade efetiva utilizou-se o modelo difusivo de Fick para a forma geométrica de placa plana. Constatou-se que os modelos de Midilli e Logaritmo melhor se ajustam aos dados experimentais da cinética de secagem. O coeficiente de difusão efetivo aumentou com o incremento da espessura da camada de material e com a elevação da temperatura. A energia de ativação do material foi de 16,61 kJ mol -1 para a espessura de 0,005 m e de 16,97 kJ mol -1 para a espessura de 0,010 m. Os critérios de AIC e BIC podem ser incluídos adicionalmente para seleção de modelos de secagem.

DRYING KINETICS OF THE SLICED PULP OF BIOFORTIFIED SWEET POTATO (Ipomoea batatas L.)

“…Thus, the Wang and Singh model was selected to represent the drying kinetics of biofortified sweet potato pulp because it presented the best adjustment for most of the drying conditions. Ribeiro et al (2014) carried out similar studies with sliced banana and Gomes et al (2018) with ground jambu mass and also used the AIC and BIC selection criteria to indicate the most suitable model to represent their drying kinetics. Figure 1 shows that different temperatures influenced water loss from the material and drying was faster for higher temperatures.…”

“…Several criteria can be used to verify the adjustment of mathematical models of drying in plant products. However, some parameters have limitations and it is necessary to adopt additional criteria to reinforce and endorse decision-making, such as the Akaike (AIC) and Schwarz's Bayesian (BIC) information criteria (Gomes et al 2018).…”

Drying kinetics of yellow mombin (Spondias mombin L.) epicarp

“…Since the Midilli model showed lower values of both AIC and BIC for all drying conditions, except for 60 o C which were the same; it was chosen to represent the drying of yellow mombin epicarp. Gomes et al (2018), working with drying of the 'jambu' leaf mass, also used AIC and BIC to select the best model. Table 3 presents the values of the parameters of the Midilli model, fitted to the experimental data of the drying kinetics of yellow mombin (Spondias mombin L.) epicarp at different temperatures.…”

“…The drying process is extremely important in the technology that allows the production of high-quality food products, allowing the preservation of physical and chemical properties and reducing the moisture content to safe levels for storage, so the product can be used in periods when the fruit is not produced (Resende et al, 2018).…”

Isotherms and Isosteric Heat Desorption of Hymenaea stigonocarpa Mart. Seeds

“…The Modified Oswin model (9) presented the lowest values for AIC and BIC, when compared to the other models, there being a greater difference between the values of these parameters in relation to those used traditionally. According to Gomes, Resende, Sousa, Oliveira, and Araújo Neto (2018) working to drying kinetics of crushed mass of 'jambu', lower AIC and BIC values indicate more adequate models.…”