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Oats have received attention because of their nutritional characteristics, especially their high-quality content of β-glucan. The drying process reduces water content; therefore they can be preserved for long periods. However, high-temperature drying process may affect the physical, chemical, and functional properties of the grains. The objective of this study was to evaluate the effect of different drying temperatures on β-glucan quality in oat grains. Grains of oats (Avena sativa, L.), cultivar Albasul, harvested at harvest moisture content of 23% were submitted to stationary drying at air temperatures of 25, 50, 75, and 100 ºC until they reached 13% moisture content. The β-glucan content was determined in samples of oat grains and extraction was performed using water as solvent at 90 ºC. The β-glucan extract was evaluated for water holding capacity, water retention capacity, capacity of displacement, and gelation properties. Stationary of oat grains at air temperatures above 25 ºC decreased the water holding capacity, whereas the content of β-glucan and the water retention capacity of β-glucan extract was affected at temperatures above 50 ºC. Physical changes such as increased gelation capacity of the β-glucan extract occurred following drying at air temperature over 75 ºC.

The aim of this study was to evaluate the quality of soybean grains stored at different temperatures (8, 13, 18, 23, and 28°C) and with different wet basis moisture content (12% and 16%). For this, kinetic models of pseudo‐zero and pseudo‐first‐order and Arrhenius law were used to verify the changes in color, lipid oxidation, and fatty acids profile. Color loss and lipid oxidation were affected by moisture content and storage temperature, with the most prominent influence observed after the fourth month of storage. The activation energy of the lipid oxidation of grains stored with a moisture content of 12% and 16% were 21.1 kJ mol−1 and 6.2 kJ mol−1, respectively. At low temperatures (8 and 13°C), there was an efficient conservation of soybeans stored with a moisture content of 16%, since the color, lipid oxidation, and profile of fatty acids were preserved for at least 6 months. Practical applications Soybeans are a commodity of high economic interest, and improper storage conditions may reduce the quality of the grain. Hence, knowledge of the degradation rate constants of soybean physicochemical properties may help reduce the loss of quality and establish proper storage conditions in the soybean processing industry. This study also supports the development of technologies for controlling temperature and relative humidity to conduct aeration of soybeans during storage, especially in hot and humid regions.

R ESU M OPropôs-se, com este trabalho, ajustar modelos matemáticos aos valores experimentais em função do teor de água e estudar os efeitos das relações de intermitência na secagem de grãos de arroz na eficiência da operação. Utilizaram-se grãos de arroz com casca produzidos na Região Sul do Rio Grande do Sul. As amostras com teor de água próximo a 20% b.u. foram secadas sob três condições de relação de intermitência: 1:1, 1:2 e 1:4; em todas as condições foram utilizados os mesmos manejos térmicos em temperaturas graduais crescentes do ar: 70, 90, 110 ± 5 °C, respectivamente, na 1ª e na 2ª e a partir da 3ª hora. Para os ajustes dos modelos matemáticos foi realizada análise de regressão não-linear pelo método Simplex e Quasi-Newton, cujos valores são os parâmetros dos modelos estimados em função da temperatura do ar de secagem. Comparando-se os coeficientes de determinação ajustados (R 2 ajustado ), o erro médio relativo (P) e estimado (SE) e a distribuição de resíduos, os resultados obtidos permitem concluir que: a relação de intermitência altera o tempo de operação e a taxa horária de secagem dos grãos de arroz e, ainda, o modelo de Midilli foi o que melhor representou a secagem intermitente do arroz em casca. Palavras-chave: secador, Oryza sativa, curvas de secagem Mathematical models for intermittent drying of rice A B ST R A C TThis study aimed to adjust mathematical models to experimental values in function of the water content and study the effects of intermittent relations in drying of paddy grains in the efficiency of operation. Paddy grains produced in the southern region of Rio Grande do Sul were used. The samples with approximately 20% water content were dried under three intermittent relation conditions: 1:1, 1:2, 1:4. In all these conditions the same thermal procedures were utilized, gradual increase in air temperature 70, 90, 110 ± 5 ºC respectively, in the 1 st , 2 nd and 3 rd hour. For the adjustments of the mathematical models, a non linear regression analysis through the Simplex and Quasi-Newton methods was carried out. The values of the parameters of the models being estimated in function of the temperature of the drying air. A comparison was carried out of the adjusted coefficient of determination (R² adjusted ), the relative mean error (P), the estimated mean error (SE) and the distribution of residues. The results showed that the intermittent relation modifies the operating time and the hourly rate of drying of the rice grains and the Midilli model was the one which best represented the intermittent drying of paddy.

The use of silo and raffia bags for the temporary grain storage has been increasing in recent years. However, the methods for monitoring a stored product are limited to visual inspections and sampling. Thus, this research aimed to real-time equilibrium moisture content monitoring to predict grain quality of corn stored in different conditions in silo and raffia bags using wireless sensor network prototype, Internet of Things (IoT) platform, and neural network algorithms. Experiments were conducted using corn grain with two initial water contents of 13% and 18% (w.b.), three storage environments with temperatures of 30, 23, and 17 C, and two types of packaging, that is, silo and raffia bags, for a 3-month storage evaluation. During the monitoring

BACKGROUND Specific studies of Brazilian wheat storage on a commercial scale on the maintenance of wheat quality are required since the continental extent of Brazil has regions of different weather and because of the diversity of the storage network. This study aimed to evaluate the technological quality (physicochemical and rheological), sanitary quality (insects, fungi and mycotoxins) and dry matter loss of wheat stored in a metal silo in a commercial storage unit. Two dynamic samples, collected during loading and unloading of wheat in silos, and four static samples, collected using a commercial pneumatic grain sampler, were used in this study. RESULTS Silo temperature was higher than 20 °C during the summer season. The temperature was approximately 15 °C from June to December and provided excellent conditions for grain aeration, which resulted in the maintenance of wheat quality, with no changes in hectoliter weight and rheological properties of wheat (falling number, wet gluten and stability). The effect of Alternaria spp. (~220) and Aspergillus flavus (~7) infection on wheat did not differ statistically during the storage period, although a slight increase in A. flavus infection was noted in February (summer season). The wheat mycotoxins deoxynivalenol, zearalenone, aflatoxins and ochratoxin A were not detected during the studied storage period. Finally, dry matter reduced by approximately 0.4% after the storage period – approximately 0.013% per month. CONCLUSION The management practices and climate conditions in southern Brazil provided excellent conditions for grain aeration at ambient air temperature and led to the maintenance of wheat quality during the post‐harvest period. © 2021 Society of Chemical Industry.

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