Modelos de predição da cinética de secagem dos grãos da algaroba

Abstract

RESUMOObjetivou-se avaliar a cinética de secagem das sementes da algaroba em camada fina e em diferentes temperaturas utilizando os modelos matemáticos semi empíricos de Henderson & Pabis, Lewis, Page, Cavalcanti Mata, Exponencial de Dois Termos e Midilli et al., para ajuste dos dados experimentais. A cinética de secagem foi realizada em triplicata utilizando uma estufa com circulação forçada de ar, com velocidade em torno de 1 m s-1, nas temperaturas de 50, 60 e 70°C e por tempos determinados até massa constante. Em todos os tratamentos, os modelos matemáticos ajustados aos dados experimentais apresentaram R² superior a 95,02% e valores de DQM inferiores a 0,0048. Dentre as equações testadas, as de Cavalcanti Mata, Midilli et al. e Page aproximaram-se mais dos pontos experimentais que os demais modelos utilizados. Os modelos de Cavalcanti Mata, Page e Midilli apresentaram os menores valores de DQM e melhores coeficientes estatísticos para descrever as curvas de secagem. Recomenda-se utilizar o modelo de Page para secagem de grãos de algaroba por possuir o menor número de termos, apresentar excelentes valores de R2 e DQM, representar de forma eficiente as curvas de secagem para as diferentes temperaturas e ser de fácil aplicação.Palavras-chave: curvas de secagem, energia de ativação, modelos matemáticos, Prosopis juliflora ABSTRACT The objective of this study was to evaluate the drying kinetics of mesquite seeds in a thin layer and at different temperatures using the semi-empirical mathematical models of Henderson & Pabis, Lewis, Page, Cavalcanti Mata, Exponential of Two Terms and Midilli et al., To adjust the experimental data. The drying kinetics was performed in triplicate using a forced air circulation oven, with speed around 1 m s-1, at temperatures of 50, 60 and 70 ° C and for determined times until constant mass. In all treatments, the mathematical models adjusted to the experimental data presented R² above 95.02% and DQM values below 0.0048. Among the tested equations, those of Cavalcanti Mata, Midilli et al. and Page were closer to the experimental points than the other models used. Cavalcanti Mata, Page and Midilli models presented the lowest DQM values and the best statistical coefficients to describe the drying curves. It is recommended to use the Page model for drying mesquite grains because they have the fewest terms, have excellent values for R2 and DQM, represent the drying curves for different temperatures efficiently and are easy to apply.

Comparison of mathematical models to describe the drying kinetics of minimally processed ponkan tangerine / Comparação de modelos matemáticos para descrição da cinética de secagem de tangerina ponkan minimamente processada

“…Figure 1 shows that an increase in temperature leads to a rise in drying rate, since dehydration time declined at higher temperatures. Several authors also demonstrated a decrease in drying time with a rise in temperature, studying different agricultural products and temperatures (MACHADO et al, 2012;MADUREIRA et al, 2011;MENEZES et al, 2013;PEREZ et al, 2013, CAVALCANTE et al, 2020.…”

Germinated seeds of three Cucurbita varieties: Physical characteristics, minerals profile, and drying behavior

“…The parameter n showed an increase in the Page and Midilli models, while in the Page modified model there was a reduction for temperatures from 50 to 70°C, the latter also reported by Almeida, Santos, Pereira, Queiroga, et al (2020) and Almeida, Santos, Pereira, Silva, et al (2020) in the drying of Azuki beans. According to Cavalcante et al (2020), normally the higher the temperature of the drying air, the lower the value of n , since there is a greater difference between the vapor pressure of the air and of the grain, promoting greater water removal.…”

“…It has been shown that the increase in temperature favors mass transfer, decreasing the equilibrium water content. Cavalcante et al (2020) obtained average values of equilibrium water content, after drying, of mesquite seeds of 4.14, 2.94, and 2.11% db for temperatures of 50, 60, and 70°C, respectively.…”