The present work aimed to perform the drying kinetics of melon seeds at different drying temperatures and to adjust the diffusion model to the experimental data considering the geometry of an infinite cylinder. The drying was carried out in an air circulation oven at temperatures of 50, 60 and 70 ºC and with an air speed of 1.5 m s-1, based on the data obtained and considering the melon seeds with infinite cylinder geometry. The parameters were calculated by the analytical solution using the diffusion equation. The coefficient of determination showed values above 0.99 and low values of the chi-square function, indicating that the diffusion model presented satisfactory adjustment to the experimental data of the drying kinetics of melon seeds. According to the data obtained in the drying kinetics of melon seeds, it was seen that the effective diffusivity, the heat transfer coefficient and the Biot number showed a strong positive correlation, indicating that the temperature increase was directly proportional to the values of the parameters calculated diffusion rates. The increase in temperature favors mass transfer, decreasing the dynamic equilibrium humidity and drying time, which varied from 1020, 940 and 880 minutes to temperatures of 50, 60 and 70 °C, it appears that for the longest interval greater time variations were the humidity variations inside the seed.

The present article aims to apply two conservation techniques (convective drying and lyophilization) to the jabuticaba peels and to characterize the powders obtained regarding the physicochemical parameters and bioactive compounds, thus evaluating their effect on their composition. Convective drying of the shells was performed in an air circulation oven at 50 °C and 1.0 m.s-1 air velocity for 24h, and lyophilization was performed at -50 °C for 48 h. In natura peels and powders obtained were characterized by the following physicochemical parameters: moisture, ash, lipids, protein, crude fiber, carbohydrates, water activity, pH, acidity, reducing sugars, total soluble solids; and bioactive compounds: anthocyanins, flavonoids, total phenolic compounds and antioxidant activity by ABTS. The use of jabuticaba bark in natura and after drying in flour form are viable for the development of new products, as a way to minimize the disposal of residues produced by the agrifood industry. Through the results obtained the jabuticaba bark flour was considered to be a source of phenolic compounds with antioxidant activity and fiber and could be considered a functional food. Comparing the drying techniques used, the lyophilization stood out because it presented a better preservation of the physicochemical parameters and the bioactive compounds.

1 Cinética de secagem do feijão azuki: modelagem matemática e propriedades termodinâmicas Azuki bean drying kinetics: mathematical modeling and thermodynamic properties Cinética de secado de frijol azuki: modelado matemático y propiedades termodinâmicas Resumo O presente trabalho tem por objetivo realizar a cinética de secagem do feijão azuki, em diferentes temperaturas de ar de secagem, ajustar modelos matemáticos aos dados experimentais e determinar as suas propriedades termodinâmicas. A cinética de secagem foi realizada nas temperaturas de 40, 50, 60, 70 e 80 °C na velocidade de ar de 1,5 m/s. Os modelos matemáticos de Parry, Page e Handerson e Pabis foram ajustados aos dados experimentais; Foram calculadas a difusividade efetiva, energia de ativação e as propriedades termodinâmicas: entalpia, entropia e energia livre de Gibbs. O modelo de Page foi o que melhor se ajustou aos dados experimentais da cinética de secagem do feijão azuki, pois apresentou elevados valores para o coeficiente de determinação e os menores valores para o desvio quadrático médio; a difusividade aumentou com aumento da temperatura de secagem e o processo apresentou uma energia de ativação de 27,69 kJ/mol; a partir das propriedades termodinâmicas foi possível concluir que, as mesmas foram afetadas pelo aumento da temperatura de secagem, com reduções de entalpia e entropia e aumento da energia livre de Gibbs indicando um processo endergônico não espontâneo. Palavras-chave: Conservação; Energia de ativação; Entalpia; Page. AbstractThe present work aims to perform the drying kinetics of adzuki beans under different drying air temperatures, to adjust mathematical models to experimental data and to determine their Research, Society and Development, v. 9, n. 3, e27932316, 2020 (CC BY 4.0) | ISSN 2525-3409 | DOI: http://dx.doi.org/10.33448/rsd-v9i3.2316 Assim, a energia de ativação (Ea) encontrada para a secagem do feijão azuki é de 27,69 kJ.mol -1 . No qual, encontra-se dentro da faixa apresentada por Zogzas et al. (1996), onde afirma que que varia para produtos agrícolas entre 12,7-110 kJ.mol -1 . Silva et al. (2008), obtiveram energia de ativação de 26,90 kJ.mol -1 ao realizarem a secagem do feijão macassar variedade sempre verde. Na Tabela 4, pode-se observar os valores obtidos para as propriedades termodinâmicas da cinética de secagem do feijão azuki.

The present work aims to determine the centesimal composition of pitomba bark, to perform its drying kinetics in three different drying air temperatures, to adjust mathematical models to experimental data and to evaluate the effect of drying temperature on its centesimal composition. add value to this underutilized product. The peels were submitted to the drying process by performing their kinetics in a fixed air velocity convective dryer (1.5 m.s-1) at 50, 60 and 70 ° C, the empirical mathematical models (Lewis, Handerson and Pabis and Page) were adjusted to the experimental data. In fresh and dehydrated barks, their centesimal composition was determined, with respect to the following parameters: humidity, total solids, ashes, lipids, proteins and carbohydrates. The Page mathematical model was indicated as the best fit due to its high R2 values (R2> 0.99) and the smallest chi-square function values for all applied drying temperatures. Lower moisture and protein values were obtained when higher temperatures were applied. For the total solids, ash and lipid content there was an increase when higher temperatures were applied. The results obtained in relation to the total carbohydrate content were relatively high evidencing that the pitomba bark flour is a high fiber powder.

This study aimed to compare rheological analyzes in the function of adding an encapsulated agent that can be found in Jabuticaba. The rheological study was performed according to the concentration of gum arabic (0, 5, 10 and 15%) and the rheological models of Bingham, Mizrahi-Berk, Casson, Herschel-Bulkley and Ostwald-de-Waelle (Law of Power) adjusted to the experimental data. Herschel-Bulkley and Mizrahi-Berk rheological models presented the best adjustments for all formulations with coefficients of determination (R2) greater than 0.99 and chi-square function less than 0.12. It was observed that the consistency index increased with the addition of gum arabic to the Herschel-Bulkley and Ostwald-de-Waele models, indicating that they became more consistent and the viscosity decreased with increasing strain rate of the fluid. Therefore, the rheological study indicated that the pulp and its formulations, with the addition of the encapsulating agent, presented non-Newtonian fluid behavior, in the specific case of a pseudoplastic.