ABSTRACT Aeration is carried out by blowing external air into the silo, with the aim to keep the temperature in the mass of stored grains at safe levels. In the present study, the energy efficiency of aeration of stored sunflower grains was estimated, and a model was proposed and tested to estimate the energy efficiency of aeration, using different algorithms in supervised and unsupervised machine learning. The objective of the work was to develop a Web application based on data mining and modeling with machine learning. The database was composed of information on the average temperature at the height of the sensors, average temperature of the silo, external ambient temperature, occurrence of aeration, if there was cooling, heating and direct heating during aeration, and the energy efficiency of the aeration process. The model for estimating the energy efficiency of the aeration process proved to be efficient, identifying that the energy efficiency was 97.78% during the aeration of stored sunflower grains. Among the classifier algorithms tested, Support Vector Machine (SVM-Poly) showed the best metrics and indicators, hence being recommended for implementation in system development networks capable of predicting the aeration status of stored grains. silo levels study estimated learning sensors cooling efficient 9778 97 78 97.78 SVMPoly SVM Poly (SVM-Poly indicators 977 9 7 97.7 97.

RESUMO A aeração é realizada por meio da insuflação do ar externo para dentro do silo, tendo como objetivo manter a temperatura da massa de grãos armazenados em níveis seguros. No presente estudo foi estimada a eficiência energética da aeração de grãos de girassol armazenados, assim como proposto e testado um modelo de estimativa da eficiência energética da aeração, utilizando diferentes algoritmos no aprendizado de máquinas supervisionado e não supervisionado. O objetivo no trabalho foi desenvolver uma aplicação Web a partir da mineração e modelagem dos dados com o aprendizado de máquinas. O banco de dados foi composto pelas informações da temperatura média do nível dos sensores, temperatura média do silo, temperatura ambiente externa, ocorrência de aeração, se houve resfriamento, aquecimento e aquecimento direto durante aeração, e a eficiência energética do processo de aeração. O modelo de estimativa da eficiência energética do processo de aeração demonstrou-se eficiente, identificando que durante a aeração de grãos de girassol armazenados a eficiência energética foi de 97,78%. Dentre os algoritmos classificadores testados na Máquina de Vetores de Suporte (SVM-Poly) apresentou as melhores métricas e indicadores, sendo recomendado para implementação em redes de desenvolvimento de sistemas capaz de predizer o status da aeração de grãos armazenados. silo seguros sensores externa resfriamento demonstrouse demonstrou eficiente 9778 97 78 97,78% SVMPoly SVM Poly (SVM-Poly indicadores 977 9 7 97,78 97,7 97,

ABSTRACT Grains are hygroscopic materials and, during storage, they are subject to exchanging moisture with the environment according to temperature and relative air humidity, making it important to monitor these factors. Digital temperature and relative air humidity sensors appear as an alternative for monitoring the moisture of grain mass inside silos; they are simple to install and use. Digital sensors present outstanding precision in temperature measurements. The objective in this study was to assess the efficiency and applicability of intergranular relative air humidity sensors linked to digital temperature sensors in the thermometry system of silos storing soybeans. Two samples of soybeans were analyzed in the upper, middle and lower thirds of the silo, for grain mass temperature, intergranular relative air humidity, estimated equilibrium moisture content according to collected data, and moisture content of the sampled grains. Moisture contents obtained from sensor measurements using the hygroscopic equilibrium equation and determined using the oven method were compared. The equilibrium moisture content estimated by the data provided by the sensors did not differ by the Tukey test (p ≤ 0.05) from the moisture content determined by the oven method. Digital temperature and relative air humidity sensors have proven to be efficient, as they contribute to estimating the equilibrium moisture content with satisfactory precision. storage factors use upper silo grains compared p 0.05 005 0 05 efficient 0.0 00 0.

RESUMO Grãos são materiais higroscópicos, e em seu armazenamento estão sujeitos às trocas de vapor de água de acordo com a temperatura e umidade relativa do ar, sendo importante o monitoramento desses fatores. Os sensores digitais de temperatura e umidade relativa do ar surgem como alternativa para monitoramento da temperatura da massa de grãos no interior de silos, apresentando simplicidade de instalação e utilização. Sensores digitais apresentam destacada precisão nas medições de temperatura. O objetivo deste estudo foi verificar a eficiência e aplicabilidade de sensores de umidade relativa do ar intergranular atrelados a sensores digitais de temperatura no sistema de termometria de silos armazenando grãos de soja. Duas amostragens de grãos de soja no terço superior, médio e inferior do silo foram analisadas para a temperatura da massa de grãos, umidade relativa do ar intergranular, teor de água de equilíbrio estimado conforme dados coletados e teor de água dos grãos amostrados. Realizou-se a comparação do teor de água obtido a partir das medições dos sensores usando a equação do equilíbrio higroscópico e pela determinação através do método da estufa. O teor de água de equilíbrio estimado pelos dados fornecidos pelos sensores não diferenciou pelo teste de Tukey (p ≤ 0.05) do teor de água determinado pela estufa. Os sensores digitais de temperatura e umidade relativa do ar demonstraram-se eficientes, visto que contribuem para estimativa do teor de água de equilíbrio com precisão satisfatória. higroscópicos fatores utilização superior amostrados Realizouse Realizou se estufa p 0.05 005 0 05 demonstraramse demonstraram eficientes satisfatória 0.0 00 0.

RESUMO O fruto de gueroba pode ser utilizado na produção de farinhas com potencial para o desenvolvimento de novos produtos oriundos da sociobiodiversidade do Cerrado. Objetivou-se estimar a cinética de secagem, bem como determinar o coeficiente de difusão efetivo e a energia de ativação para a polpa dos frutos de gueroba submetida a diferentes temperaturas de secagem. Os frutos de gueroba foram despolpados manualmente, retirando o mesocarpo com o epicarpo, sendo esse material identificado como a polpa. O material foi submetido à secagem em estufa nas temperaturas de 40, 50, 60 e 70 °C. Aos dados experimentais foram ajustados modelos de regressão não linear. O modelo mais adequado foi selecionado com base no coeficiente de determinação, erro médio relativo e estimado, teste de Qui-quadrado, AIC e BIC. Com o aumento da temperatura de secagem, menor é o tempo do processamento para se atingir o mesmo teor de água, devido ao aumento da difusividade da água no interior do produto. O modelo de Midilli apresentou o melhor ajuste aos dados experimentais obtidos. Os coeficientes de difusão efetivos da polpa dos frutos de gueroba apresentaram magnitudes entre 3,11 x 10-9 a 5,84 x 10-9 m2 s-1 para as temperaturas de 40 a 70 °C. A energia de ativação do processo foi de 18,34 kJ mol-1.

ABSTRACT The ‘Gueroba’ fruit can be used to produce flours with potential for the development of new products from the ‘Cerrado’ socio-biodiversity. The objective was to estimate the drying kinetics and determine the effective diffusion coefficient and activation energy for the pulp of ‘gueroba’ fruits subjected to different drying temperatures. ‘Gueroba’ fruits were manually pulped, removing the mesocarp with the epicarp, and this material was identified as the pulp. The material was subjected to oven drying at temperatures of 40, 50, 60 and 70 °C. Nonlinear regression models were fitted to the experimental data. The most adequate model was selected through the coefficient of determination, mean relative and estimated errors, Chi-square test, AIC and BIC. As the drying temperature increases, the processing time to achieve the same moisture content decreases, due to the increase in water diffusivity inside the product. The Midilli model showed the best fit to the experimental data obtained. The effective diffusion coefficients of the pulp of ‘gueroba’ fruits showed magnitudes between 3.11 x 10-9 to 5.84 x 10-9 m2 s-1 for temperatures from 40 to 70 °C. The activation energy of the process was 18.34 kJ mol-1.

RESUMO No presente estudo, objetivou-se ajustar diferentes modelos aos dados experimentais da secagem das sementes de tamarindo (Tamarindus indica L.) e selecionar o melhor modelo, determinar o coeficiente de difusão efetivo, a energia de ativação e as propriedades termodinâmicas para o processo, durante a secagem em diversas temperaturas. O experimento foi conduzido no Laboratório de Pós-Colheita de Produtos Vegetais do Instituto Federal Goiano - Campus Rio Verde. As sementes com teor de água inicial de 18 ± 0,25% base seca, foram secas em estufa com ventilação de ar forçada, nas temperaturas controladas de 45, 60, 75 e 90 °C, em quatro repetições. Aos dados experimentais foram ajustados a modelos de regressão não linear utilizados para descrição do fenômeno. Para representar a secagem das sementes de tamarindo o modelo de Midilli foi selecionado para a faixa de 45 a 60 ºC, e para 75 a 90 ºC o modelo ajustado foi o de Dois termos. O coeficiente de difusão efetivo aumenta com a elevação da temperatura do ar de secagem, sendo descrito pela equação de Arrhenius, com energia de ativação de 35,16 kJ mol-1. A entalpia e entropia decrescem, enquanto a energia livre de Gibbs aumenta com o incremento da temperatura de secagem.

ABSTRACT In the present study, the objective was to fit different models to the experimental data of drying of tamarind (Tamarindus indica L.) seeds and to select the best model, to determine the effective diffusion coefficient, activation energy and thermodynamic properties for the process during drying at different temperatures. The experiment was carried out at the Laboratory of Post-Harvest of Vegetable Products of the Instituto Federal Goiano (Federal Institute Goiano) - Campus of Rio Verde, GO, Brazil. Seeds with initial moisture content of 18 ± 0.25% dry basis were oven dried with forced air ventilation, at controlled temperatures of 45, 60, 75 and 90 °C in four repetitions. Nonlinear regression models used to describe the phenomenon were fitted to the experimental data. To represent the drying of tamarind seeds, the Midilli model was selected for the range from 45 to 60 ºC and the Two terms model was selected for the range from 75 to 90 ºC. The effective diffusion coefficient increases with the increase of drying air temperature, being described by the Arrhenius equation, with activation energy of 35.16 kJ mol-1. Enthalpy and entropy decreases, while Gibbs free energy increases with increasing drying temperature.

ABSTRACT Tamarind is used in the food and pharmaceutical industry, and its seed is the main means for the reproduction of this species, thus justifying studies that ensure its post-harvest viability. This research aimed to study the thermodynamic properties of tamarind seeds as a function of the equilibrium moisture content. The experimental data of the water activities were obtained by the indirect static method. The Cavalcanti Mata model was used to determine the thermodynamic properties of tamarind seeds, as it was the model that best fitted the experimental data of the desorption isotherms. The results showed that the thermodynamic properties are influenced by the moisture content and temperature, with an increase in the energy required to remove water from the product with a decrease in moisture content. The net isosteric heat of desorption increases with a reduction of moisture content ranging from 2,618.85 to 2,510.25 kJ kg−1 for the moisture content range of 10.52 to 21.10% db. The latent heat of vaporization, the differential enthalpy, and the Gibbs free energy increase with a reduction of the moisture content of tamarind seeds.

RESUMO Objetivou-se, com este estudo, determinar as isotermas de dessorção e o calor isostérico das sementes de Annona crassiflora Mart., utilizando os critérios de informação de Akaike (AIC) e informação bayesiano de Schwarz (BIC) para auxiliar na escolha do modelo de regressão não linear. As isotermas de dessorção foram determinadas pelo método estático indireto e a atividade de água foi obtida por meio do equipamento HygroPalm; o produto foi acondicionado no equipamento em B.O.D. regulada a 10, 20, 30 e 40 °C. Os dados experimentais foram ajustados a diversos modelos de regressão não linear, pelo método Gauss-Newton. As isotermas de dessorção de sementes de Annona crassiflora Mart. podem ser representadas pelos modelos de Chung-Pfost, Copace, GAB Modificado, Henderson Modificado, Oswin Modificado, Sabbah e Sigma Copace. Contudo, o modelo Sigma Copace apresentou melhor ajuste aos dados experimentais, com memores valores de AIC e BIC, sendo escolhido para representar as isotermas de dessorção das sementes de Annona crassiflora Mart. O calor isostérico aumentou com a diminuição do teor de água, sendo necessária maior quantidade de energia para retirar a água das sementes, com valores variando de 2541,64 a 2481,56 kJ kg-1, para a faixa do teor de água de 5,69 a 14,93% base seca.

ABSTRACT The objective of this study was to determine the desorption isotherms and isosteric heat of Annona crassiflora Mart. seeds, using Akaike information criterion (AIC) and Schwarz’s Bayesian information criterion (BIC) to assist in the choice of the nonlinear regression model. The desorption isotherms were determined by indirect static method and water activity was obtained using the instrument HygroPalm; the product was put in the device in B.O.D. chamber set at 10, 20, 30 and 40 °C. Several nonlinear regression models were fitted to the experimental data by the Gauss-Newton method. The desorption isotherms of Annona crassiflora Mart. seeds can be represented by the models of Chung-Pfost, Copace, Modified GAB, Modified Henderson, Modified Oswin, Sabbah and Sigma Copace. However, the Sigma Copace model showed better fit to the experimental data, with lower AIC and BIC values, being chosen to represent the desorption isotherms of Annona crassiflora Mart seeds. Isosteric heat increased with decreasing moisture content, requiring a greater amount of energy to remove water from seeds, with values ranging from 2541.64 to 2481.56 kJ kg-1, for the moisture content range from 5.69 to 14.93% on a dry basis.

ABSTRACT The knowledge of hygroscopicity is essential for the storage of tamarind seeds, but there is a limitation of a judicious statistical parameter to define the best mathematical model to adjust the isotherms of plant products. Therefore, this study aimed to determine the desorption isotherms of tamarind seeds and test the Akaike information criterion (AIC) and Schwarz Bayesian information criterion (BIC) for choosing the best mathematical model. Seeds with an initial moisture content of 21.00 ± 0.10% dry basis (db) were dried at 45 °C until they reached moisture contents of 17.27 ± 0.10, 15.04 ± 0.16, 14.14 ± 0.06, 12.41 ± 0.17, and 10.52 ± 0.12% db. The water activity of the product was determined by the static-indirect method at temperatures of 10, 20, 30, and 40 °C. Mathematical models frequently used to predict the isotherms of plant products were adjusted to the experimental data. The Cavalcanti Mata model is recommended to estimate the desorption isotherms of tamarind seeds because it presents better adjustments. The AIC and BIC criteria contribute to the choice of the model to predict the desorption isotherms of tamarind seeds.

RESUMO O fruto da cajazeira (Spondias mombin L.) apresenta características relevantes para industrialização e possuem aroma agradável e sabor ácido-adocicado, possui quantidades relevantes de vitamina A e carotenoides no epicarpo do cajá. Objetivou-se, ajustar diferentes modelos matemáticos aos dados experimentais, utilizando como critérios para selecionar o melhor modelo - o Critério de Informação de Akaike (AIC) e o Critério de Informação Bayesiano de Schwarz (BIC), bem como avaliar o coeficiente de difusão efetivo e determinar a energia de ativação para o epicarpo de cajá submetido a diferentes condições de secagem. O experimento foi desenvolvido no Instituto Federal de Educação, Ciência e Tecnologia Goiano. O epicarpo dos frutos de cajá com teor de água inicial 2,89 (base seca, b.s.) foram submetidos à secagem em temperaturas de 40, 50, 60 e 70 °C até teor de água final de 0,11, 0,10, 0,09 e 0,08 (b.s.), respectivamente. O modelo de Midilli apresentou o melhor ajuste aos dados experimentais obtidos. A escolha do modelo foi confirmada pelos critérios de AIC e BIC. O aumento da temperatura de secagem promoveu aumento do coeficiente de difusão efetivo, e a energia de ativação do processo foi de 21,50 kJ mol-1.

ABSTRACT Yellow mombin (Spondias mombin L.) fruits have relevant characteristics for industrialization and exhibit a pleasant aroma and sour-sweet taste, with significant amounts of vitamin A and carotenoids in their epicarp. The objective was to fit different mathematical models to the experimental data, using as criteria to select the best model - the Akaike Information Criteria (AIC) and Schwarz’s Bayesian Information Criteria (BIC), as well as to evaluate the effective diffusion coefficient and to determine the activation energy for yellow mombin epicarp submitted to different drying conditions. The experiment was carried out at the Instituto Federal de Educação, Ciência e Tecnologia Goiano, Brazil The epicarp of yellow mombin fruits with initial moisture content of 2.89 (dry basis, d.b.) were submitted to drying at temperatures of 40, 50, 60 and 70 °C until final moisture contents of 0.11, 0.10, 0.09 and 0.08 (d.b.), respectively. The Midilli model showed the best fit to the experimental data obtained. The choice of the model was confirmed by the AIC and BIC criteria. The increase of the drying temperature promoted increase in the effective diffusion coefficient, and the activation energy of the process was 21.50 kJ mol-1.

ABSTRACT Drying is the most widely used process to ensure the quality and stability of plant products. Therefore, this study aimed to determine the effective water diffusivity and activation energy in grain sorghum during drying at different temperatures and initial moisture contents. Sorghum grains (cultivar DeKalb 640) were harvested with an initial moisture content of 0.49 kg water kg−1 dry matter. The effective diffusion coefficient was determined from different initial moisture contents of approximately 0.49, 0.40, 0.31, and 0.23 kg water kg−1 dry matter. Grains with different moisture contents were dried under four temperature conditions of 40, 60, 80, and 100 °C on perforated trays. The spherical geometry model was used for liquid diffusion. The experiment was conducted in a completely randomized design in a 4 × 4 factorial scheme (four moisture contents × four temperatures), with three replications. Data were subjected to analysis of variance and regression using the statistical software SISVAR®. Sorghum grain diffusivity increases at the same drying temperature as an increase of the initial moisture content of grains. The activation energy was higher for grains with higher initial moisture content, with values of 27.32, 26.75, 22.55, and 20.94 kJ mol−1, respectively.

ABSTRACT Biofortified sweet potato (Ipomoea batatas) is one of the foods with the highest contributions of carotenoids in the diet, especially provitamin A carotenoids. Thus, this study aimed to analyze the drying kinetics of the biofortified sweet potato pulp using the Akaike (AIC) and Schwarz's Bayesian (BIC) information criteria for model selection, as well as determine the effective diffusion coefficient and activation energy under different drying conditions. The biofortified sweet potatoes were sliced into chips and submitted to drying in an air circulation oven at 1.0 m s−1 at temperatures of 45, 55, 65, and 75 °C until constant mass. The mathematical models Wang and Singh, Verma, Thompson, Page, Newton, Midilli et al., logarithmic, Henderson and Pabis, two-term exponential, two-term, diffusion approach, frequently used to predict the drying of vegetal products, were adjusted to the data. The Wang and Singh model was selected to represent the drying of the biofortified sweet potato pulp by exhibiting the best adjustment for most conditions. The AIC and BIC criteria were suitable for selecting the Wang and Singh model. The effective diffusion coefficient increased as drying air temperature increase and the activation energy for liquid diffusion was 29.18 kJ mol−1.