Physical properties of safflower grains. Part II: Volumetric shrinkage

Abstract

A B S T R A C TAgricultural products usually have their size reduced during the drying process. The quantification of the reduction in the dimensions is important for the development and optimization of equipment for the post-harvest of the product. The aim of the present study was to evaluate the effect of the variation in the moisture content during drying on the volumetric shrinkage of safflower grains and their respective axes. Safflower grains were harvested with an initial moisture content of approximately 0.445 decimal d.b. (dry basis) and subjected to drying in an oven with forced air circulation at 40 °C, until the grains reached a final moisture content of 0.073 ± 0.008 decimal d.b. During drying, the contraction of the axes, unit volumetric shrinkage and volumetric shrinkage of the mass of safflower grains were determined at different moisture contents. Based on these results, it can be concluded that reducing the moisture content causes a reduction in the axes of safflower grains and, consequently, reductions in the unit volumetric shrinkage and volumetric shrinkage of the mass of approximately 16 and 13%, respectively, and both variables can be represented by the linear shrinkage model. Propriedades físicas dos grãos de cártamo. Parte II: Contração volumétrica R E S U M O Normalmente, os produtos agrícolas têm suas dimensões reduzidas durante o processo de secagem. A quantificação da redução dessas dimensões é importante para o desenvolvimento e otimização de equipamentos destinados à pós-colheita do produto. Em virtude disto, objetivou-se, com o presente trabalho, avaliar o efeito da variação do teor de água durante a secagem sobre a contração volumétrica dos grãos de cártamo e de seus respectivos eixos. Foram utilizados grãos de cártamo colhidos com teor de água inicial de aproximadamente 0,445 decimal b.s. (base seca) e submetidos à secagem em estufa com circulação forçada de ar, na temperatura de 40 °C, até os grãos atingirem o teor de água final de 0,073 ± 0,008 decimal b.s. Durante a secagem, os índices de contração dos eixos e contração volumétrica unitária e da massa de grãos de cártamo foram determinados em diferentes teores de água. Com base nos resultados obtidos pode-se concluir que a redução do teor de água causa redução dos eixos dos grãos de cártamo; consequentemente, a redução dos valores do índice de contração volumétrica da massa e unitária de aproximadamente 16 e 13%, respectivamente, em que ambas as variáveis podem ser representadas pelo modelo de contração linear.

Determination and modeling of physical and aerodynamic properties of coffee beans ( Coffea arabica ) during the drying process

“…Note that the coffee beans showed a volumetric reduction of ~20% in relation to the initial volume for the moisture content ranging from 1.13 to 0.07(decimal, d.b.). The results found in this study are in line with those observed byMartins et al (2017) for sunflower grains. In this work, the authors verified a volumetric contraction of 16% during drying, for moisture contents varying between 0.45 and 0.08(decimal, d.b.).…”

Herbaceous Oil Crops, a Review on Mechanical Harvesting State of the Art

“…Excessive rain and high humidity after physiological maturity of the seed may cause sprouting in the head. Safflower seeds are small, i.e., thousand-grain mass varies from 55.30 g to 41.30 g [191]. For a proper seed germination, both ploughing and harrowing are required.…”

Effect of drying air temperature on the physical properties of macauba kernels (Acrocomia aculeata)

“…Agricultural products show significant changes in their physical properties, including size and shape, when subjected to conditions capable of modifying their moisture (OBA et al, 2019). Understanding these physical properties is of paramount importance for the execution and planning of post-harvest stages (MARTINS et al, 2017a).…”

“…Reducing the amount of water in the material reduces the biological activity and physicochemical changes that occur in the post-harvest period (CARVALHO et al, 2022). Knowledge of the physical properties of agricultural products is of fundamental importance for the development and optimization of equipment for post-harvest (MARTINS et al, 2017a). According to Ramashia et al (2018), the knowledge of the physical properties of agricultural products are essential for reducing costs and preserving them during post-harvest.…”