ABSTRACT The objective of this study was to describe the constant drying flux stage, as well as obtaining the critical moisture content during the convective drying of jambu leaf paste crushed under different conditions and characterizing the physical properties of the material after drying. Drying was carried out in an air circulation oven at a speed of 1.0 m s-1 and temperatures of 60, 70 and 80 ºC and layer thicknesses of 0.005 and 0.01 m. To determine the constant rate stage, the mass fluxes and the drying rate were calculated. Segmented polynomials were used to estimate the critical moisture content. Under the analyzed conditions, a typical drying behavior was found, demonstrating the existence of a significant period of constant drying rate for the mass of ground jambu leaves. Critical moisture content as a function of thickness and temperature did not show a trend. The material showed favorable physical characteristics, such as high solubility and cohesiveness, free flow, and good wettability, characteristics that add value to the raw material and for the availability of a new product to the market in the condition of packaging.

RESUMO Neste estudo objetivou-se descrever o estágio de fluxo de secagem constante, bem como obter o teor de água crítico durante a secagem convectiva da pasta de folhas de jambu trituradas em diferentes condições e caracterizar as propriedades físicas do material após a secagem. A secagem foi realizada em estufa de circulação de ar com velocidade de 1,0 m s-1 nas temperaturas de 60, 70 e 80 ºC e espessuras da camada de 0,005 e 0,01 m. Para a determinação do estágio de taxa constante, foram calculados os fluxos de massa e a taxa de secagem. Os polinômios segmentados foram utilizados para estimar o teor de água crítico. Nas condições analisadas houve um comportamento típico de secagem, demonstrando a existência de um expressivo período de taxa constante de secagem para a pasta de folhas de jambu trituradas. Os teores de água críticos em função da espessura e temperatura não apresentaram uma tendência. O material apresentou características físicas favoráveis, como alta solubilidade e coesividade, escoamento livre e boa molhabilidade, características que agregam valor à matéria-prima e para a disponibilização de um novo produto ao mercado em condição de acondicionamento.

Abstract Thus, the objective of this work was to evaluate the performance of industrial drying and the quality of soybean grains using a direct-fire furnace automatically fed by wood chips. To represent the grains before drying, four samples were collected together with the sampling of the loads in the trucks carried out to classify the product in the storage unit. At drying, performance evaluations and specific energy consumption were carried out. The grains were evaluated for moisture content, germination, electrical conductivity, apparent specific mass, color, acidity index, and PAHs. Drying showed an average efficiency of 75.50%. The average chip consumption was 0.4403 kg of chip/kg of evaporated water. The specific energy consumption was 8,099.50 kJ/kg of evaporated water. The grains showed differences after drying in the characteristics of germination, electrical conductivity, and chroma. Six PAHs were detected in the samples before drying: (B(a)A, Chr, 5 MC, B(j)F, Dib(ai)P, and IcdP). After drying, in addition to the PAHs obtained before drying, five more were detected (B(b)F, B(k)F, B(a)P, Dib(al)P, and Dib(ah)A). Mean PAH concentrations were higher than the maximum values allowed by European Union legislation.

ABSTRACT Sorghum ( Sorghum bicolor L. Moench) is a crop of paramount importance for Brazil, used in human and animal food. Considering the reduced number of studies on the influence of using a densimetric table in seed processing and its respective reprocessing to the equipment, this study aimed to evaluate the physiological quality of processed sorghum seeds reprocessed in a densimetric table and stored for three months. The treatments consisted of four collection points in the terminal part of the densimetric table, representing the processing material: upper part (P1), upper middle part (P2), middle part (P3), and lower part (D). Subsequently, the samples that were reprocessed in the table came from P3 and were divided into the upper part, which was followed to bagging (P3R1), and the lower part (P3R2), which followed for disposal, totaling six treatments. Storage was performed in a refrigerated environment, using a completely randomized design, with the means being compared by Tukey’s test at 5%. We concluded that the reprocessing of sorghum seeds in the densimetric table can improve the physical quality of a lot due to its standardization at the end of the stages, contributing to the improvement of the physiological quality and use of the material that would be discarded. The equipment performance allows the removal of seed fractions with lower apparent specific mass and promotes positive stratifications in the physiological quality of sorghum seed lots.

ABSTRACT Endive is a vegetable traditionally eaten as a raw or cooked salad. It is a source of important nutritional compounds and one of the procedures for its industrialization is drying, which increases its shelf life, preserves the nutrients and reduces losses due to microorganisms. This research evaluated the drying kinetic of endive leaves at different temperatures and adjusted the experimental data according to mathematical models. The experimental design was completely randomized in triplicate, with each sample unit being a perforated aluminum tray containing about 100 g fresh leaves. The endive leaves were dried in an oven at 50, 60, 70 and 80°C. The mathematical models were adjusted according to the experimental data; non-linear regression analysis was performed by Gauss-Newton and Quasi-Newton methods. In all conditions, the mathematical models that best fitted the drying kinetics of the endive leaves were Midilli, Logarithmic and Valcam. The Logarithmic model, under these drying conditions, can be accurately described as suitable for predicting and simulating the drying kinetic of endive leaves, as it showed the best results in the statistical parameters evaluated.

RESUMO Chicória é um vegetal tradicionalmente consumido como salada crua ou cozida. É uma fonte de importantes compostos nutricionais e um dos procedimentos para sua industrialização é a secagem, que aumenta a vida útil, preserva seus nutrientes e reduz as perdas por microrganismos. Esta pesquisa avaliou a cinética de secagem de folhas de chicória em diferentes temperaturas e ajustou os dados experimentais de acordo com modelos matemáticos. O delineamento experimental foi inteiramente casualizado, em triplicata, onde cada unidade amostral era uma bandeja de alumínio perfurada, contendo cerca de 100 g de folhas frescas. As folhas de chicória foram secas em estufa, a 50, 60, 70 e 80°C. Os modelos matemáticos foram ajustados de acordo com os dados experimentais e, a partir deles, a análise de regressão não-linear foi realizada pelos métodos de Gauss-Newton e Quasi-Newton. Em todas as condições, os modelos matemáticos que melhor se ajustaram à cinética de secagem das folhas de chicória foram o Midilli, o Logarítmico e o Valcam. O modelo logarítmico, nessas condições de secagem, pode ser descrito com precisão como adequado para prever e simular a cinética de secagem das folhas de chicória, pois apresentou melhores resultados nos parâmetros estatísticos avaliados.

ABSTRACT This study is dedicated to the development of a methodology based on supervised machine learning for soybean classification and justified as technological innovation to predict whether soybean classification is in the standard or non-standard established by normative instruction No. 11/2007 of the Ministry of Agriculture, Livestock, and Food Supply (MAPA). This study aimed to develop a website using supervised machine learning to classify soybeans, providing an assertive decision-making process in real-time. A technological tool was created to assist the farmer and the storage unit in the classification of soybeans, considering the perceived reality and potential instruments consistent with the reality of the area. Therefore, a website in Python language was created using the Pandas, Pandas Profiling, Seaborn, Matplotlib, NumPy, Scikit-learn, PyCaret, and Streamlit libraries. In the end, the system could predict whether the soybean is in the standard or non-standard established by the soybean classification normative. In this sense, the results showed the robustness and precision of the proposed new methodology.

Abstract The objective was to produce flour from sorghum grains, to determine the physicochemical and microbiological characteristics, and to develop different formulations of cookies, with total and partial replacement of rice flour, evaluating the moisture content, color, expansion factor and texture profile - TPA. Five formulations were processed, as follows: control - 0%; F1 - 25%; F2 - 50%; F3 - 75% and F4 - 100% sorghum flour. The sorghum flour showed physical, chemical and microbiological characteristics in accordance with current legislation, and can be inserted into human food. The different cookie formulations after baking had a moisture content below 7%. With the addition of sorghum flour, the cookies showed lower light F4 – 32.35 L*. The addition of sorghum flour did not affect the expansion factor of the cookies, with average value of 2.13. The different concentrations of sorghum flour, showed interference in analysis of the Texture-TPA profile, the F3 formulation, presented higher values of hardness 25594.44 N, fracturability 251 N, cohesiveness 0.27. Elasticity has not been compromised. The highest values of gumminess 53.08 N, chewability 1471.15 mJ were found in the formulation F4 – 100% FS. These results may help improve the quality of sorghum-based gluten-free foods for celiac consumers.

Abstract The objective of this work was to evaluate the drying performance, the quality of the corn grain and the contamination by polycyclic aromatic hydrocarbons (PAHs) using a direct-fired furnace fed automatically by wood chips. Samples were collected at five-minute intervals, 12 samples before drying and 12 samples after drying. The following experimental evaluations were carried out: dryer – performance and fuel consumption; grains – moisture content, germination, electrical conductivity, apparent specific mass, mass of a thousand grains, color and PAHs. The dryer showed an average efficiency of 83.61%. The average consumption of wood chips was 0.3932 kg of chips per kilogram of evaporated water. Differences were observed in the grains after drying for the characteristics of mass of a thousand grains, apparent specific mass, germination and electrical conductivity. The average concentrations of PAHs in corn grains were higher than the maximum values allowed by the European Union legislation.

Abstract The objective of this study was to evaluate the drying system using a dryer with furnace automatically fed with eucalyptus chips and another dryer manually fed with eucalyptus firewood, as well as assessing the quality of corn grains. Harvest was mechanically performed and the grains were transported by trucks to the storage unit for drying. Corn grain drying was conducted in mixed-flow dryers with a nominal capacity of 100 tons per hour. For air heating, two direct-fired furnaces were used, one automatically fed with eucalyptus chips and the other manually fed with firewood. Corn grains were evaluated for moisture content, apparent specific mass, thousand-grain weight, polycyclic aromatic hydrocarbons (PAHs), electrical conductivity and color. Drying corn grains with direct fire using firewood or chips as fuel causes contamination by PAHs. In general, the use of firewood or chips did not influence the quality of thousand-grain weight, apparent specific mass and color, while the use of chips increased electrical conductivity. It is essential that research advances in this subject, prioritizing the contamination of food, with proven carcinogenic activity, which should be treated as a high risk to public health.

Abstract The Croton urucurana Baill species is known in Brazil as “sangra d’água” and is popular due to its medicinal properties. For better processing of herbal medicines, it is essential that efficient drying and storage techniques are developed and that compounds are preserved. Therefore, this study aimed to select models through multivariate cluster analysis applying Akaike (AIC) and Bayesian information criteria (BIC) to describe Croton urucurana leaves drying kinetics at different temperatures (40-70 °C). The initial moisture content in Croton urucurana leaves was 1.791, 1.841, 2.196 and 2.144 kg water kg dry matter-1, and 8.25, 7.75, 4.25 and 2 hours were required to reach hygroscopic equilibrium, with a final moisture content of 0.134, 0.105, 0.065 and 0.0601 kg water kg dry matter-1, at 40, 50, 60 and 70 °C, respectively. The models with the greatest similarity to the experimental data were Diffusion Approximation; Cavalcanti Mata; Two-term; Two-term Exponential; Modified Henderson & Pabis; Logarithmic; Midilli; Page and Verma. The multivariate cluster technique associated with AIC and BIC criteria during model selection is a great applicability tool to help decision-making when evaluating the drying plant leaves. The Cavalcanti Mata mathematical model was selected to represent the drying kinetics.

Abstract Araticum (Annona crassiflora) fruits have relevant characteristics for industrialization, a characteristic aroma and a slightly acidic flavor, with relevant amounts of vitamins A, C, B1 and B2. The objective of this study was to fit different mathematical models to the experimental data, evaluate the effective diffusion coefficient and determine the activation energy for the araticum epicarp subjected to different drying conditions. The epicarps of araticum fruits were dried at temperatures of 40, 50, 60 and 70 °C. Midilli, Logarithmic and Two Terms models can be used to represent the drying of araticum epicarp, and the Two Terms model was selected according to the Akaike Information Criterion (AIC) and Schwarz’s Bayesian Information Criterion (BIC). The linear model satisfactorily represented the effective diffusion coefficient as a function of drying temperature. In the evaluation of enthalpy, entropy and Gibbs free energy, both enthalpy and entropy tend to decrease when temperature increases. The higher the temperature used for drying of araticum epicarp, the lower the value of diffusivity, i.e., the lower the resistance to water removal.

Abstract The drying is one of the stages of processing Brazil nuts, being an important stage due to the high moisture content and water activity of the product. This study aimed to adjust mathematical models to the drying kinetics data of Brazil nuts, calculating the effective diffusion coefficient and obtaining activation energy for the drying process. Brazil nuts were collected in amazon region, and then the product was homogenized for processing. The nuts were subjected to drying in a forced ventilation oven at temperatures of 40, 50, 60, 70 and 80 °C in 4 replicates, each one consisting of approximately 200 g of samples in aluminum containers. Mathematical models were adjusted to the experimental data of the moisture content ratio. Thompson, Midilli, Logarithmic and Two Terms models are suitable for estimating the drying of Brazil nuts. The Two Terms model was selected to represent the drying phenomenon for presenting better results in the analyzed parameters. The effective diffusion coefficient increased with increasing temperature and the activation energy for the liquid diffusion in the drying was 35.69 kJ mol-1.

ABSTRACT. Drying is an important step in the post-harvest processes as a way of product conservation and quality preservation. In this context, this study aimed to evaluate the effect of continuous and intermittent drying of maize grains with different rest periods on the integrity of their micro- and macroscopic structures. Maize grains were harvested with a moisture content of 0.3399 ± 0.001 dry basis (db) and subjected to continuous and intermittent drying with 4, 8, 12, and 16 hours of rest period. An experimental fixed-bed dryer, with controlled drying air conditions at a temperature of 100 °C and air flow of 1.5 m3 min.−1 m−2 (12 m3 min.−1 m−3), was used. Continuous drying was completed with a moisture content of 0.1628 ± 0.0003 db, whereas intermittent drying was interrupted with 0.2195 ± 0.0002 db and resumed after rest. The drying rate, integrity through grain images, the conformation of particles through scanning electron microscopy, and cell membrane integrity were evaluated. The drying rate increased with an increase in the rest period, the increase in rest period reduced the intensity of cracks, and the reduction in rest period led to higher dispersion and reduction in the size of starch granules and lower integrity of cell membranes.

Abstract Evaluate texture in relation to the hardness, fracturability, cohesiveness, elasticity and chewiness parameters of Brazil nut kernels stored in different packagings over time of 240 days. The experimental compression tests were conducted in 15 kernels for each treatment using a texturometer equipped with a load cell of 25 kg. The following parameters were used: pre-test speed: 2.0 mm s-1; test speed: 0.50 mm s-1 and post-test speed: 0.50 mm s-1; 10% compression and rest period of 2 s between the two cycles; initial load of 7 g; and data acquisition rate of 10 points per second. The data were subjected to analysis of variance (ANOVA), followed by the Scott-Knott test at 5% significance level, using R software. Storage time interfered in the moisture content, leading to the highest value initially, 4.03% w.b., and lowest value at 120 days, with an average of 2.705% w.b. The hardness values of the kernels stored in the polypropylene packaging remained the same throughout storage. The different packagings and storage times had no influence on the fracturability parameter. Polypropylene and vacuum packaging did not influence the elasticity of kernels throughout storage. Cohesiveness and chewiness showed differences between the packagings and between the storage periods.

Abstract The objective of this study was to evaluate the influence of drying treatment on the characteristics physical, chemical, technological properties and bioactive of turmeric flour. The flour was obtained from the drying of rhizomes in a forced air circulation oven at temperatures of 45, 55, 65 and 75 °C. The analyzes performed were: pH, instrumental color, microstructure, granulometry, water and oil absorption indices, water solubility indices, and antioxidant activity. The characteristics of the flours significantly affected were moisture, protein, lipid and ash contents. The antioxidant capacity with the DPPH radical, for flour at the drying temperature of 45 °C, presented the highest value 36.55 Mmol Trolox g-1, and 7686.32 Mmol FeSO4 g-1 the FRAP radical at 65 °C.The phenolic content varied according to the solvent applied to obtain the extract, the mean values of total phenolic compounds for each temperature were: 0.419, 0.332, 0.316, 0.283 mg GAEa 100 g-1for temperatures 45, 55, 65 and 75°C respectively. Water solubility index (WSI) and oil absorption index ranged from 12.45 g g-1 to 11.78 g g-1 and from 2.54 g g-1 to 2.49 g g-1, respectively, for temperatures of 45 °C and 75 °C. The results of the present study indicated that temperature influences the physicochemical and technological properties of turmeric flour.

RESUMO O cártamo é uma cultura de elevado valor econômico que possui alto teor de óleo nos grãos e grande versatilidade industrial com vários benefícios à saúde humana. Assim, como outras culturas agrícolas é comum o armazenamento do cártamo para disponibilização em diferentes épocas do ano, e devido suas características higroscópicas tornam-se relevantes estudos que avaliem o efeito da temperatura e da umidade relativa do ar no teor de água. Deste modo, objetivou-se neste estudo determinar as isotermas de adsorção de água das sementes de cártamo e analisar as propriedades termodinâmicas. Os teores de água de 6,5; 6,9; 7,3; 7,7; 8,3 e 9,1% (base seca) foram obtidos por adsorção em condições controladas de temperatura (30 °C) e umidade relativa do ar (90%). As isotermas de adsorção foram obtidas pelo método estático indireto em diferentes temperaturas (10, 20, 30 e 40 °C). Com o aumento da temperatura, para um mesmo teor de água, tem-se elevação da atividade de água e, para uma atividade de água constante, os valores do teor de água de equilíbrio diminuíram com o aumento da temperatura. O modelo de Chung-Pfost apresentou o melhor ajuste para descrever o fenômeno de higroscopicidade das sementes de cártamo. As propriedades termodinâmicas foram influenciadas pelo teor de água das sementes, reduzindo a energia necessária para a absorção de água no produto com o aumento da adsorção, sendo a teoria da compensação entalpia-entropia controlada pela entalpia.

ABSTRACT Safflower is a crop of high economic value with high oil concentration in its seeds and great industrial versatility, besides various benefits to human health. As with other agricultural crops, it is common to store safflower to make it available in different periods of the year and, due to its hygroscopic characteristics, studies evaluating the effect of temperature and air relative humidity on its moisture content become relevant. Thus, the objective of the present study was to determine the water adsorption isotherms of safflower seeds and analyze their thermodynamic properties. Moisture contents of 6.5, 6.9, 7.3, 7.7, 8.3 and 9.1% (dry basis) were obtained by adsorption under controlled conditions of temperature (30 °C) and relative air humidity (90%). The adsorption isotherms were obtained by the indirect static method at different temperatures (10, 20, 30 and 40 °C). As temperature increased, for the same moisture content, there was an increase in water activity and, for constant water activity, the values of equilibrium moisture content decreased with increasing temperature. Chung-Pfost model showed the best fit to describe the phenomenon of hygroscopicity of safflower seeds. The thermodynamic properties were influenced by the moisture content of the seeds, reducing the energy necessary for water absorption in the product with the increase in adsorption, and the enthalpy-entropy theory was controlled by enthalpy.