Mathematical modeling and thermodynamic properties of the drying kinetics of trapiá residues

Abstract

Trapi a (Crataeva tapia L.) is an edible, arboreal fruit species found in Brazil, of which the pulp is suitable for industrialization. The residual peel and seeds are sources of bioactive compounds and can be used after appropriate treatment. Such fruit parts have been introduced as ingredients in various applications to reduce waste in agricultural production and take advantage of the presence of nutrients, but to make them viable for industrial use, the moisture content of the product should be reduced, enabling it to be conserved at room temperature and transformed into powder or flour. The objective of this study was to assess the convective drying of residual trapi a peel and seeds in 0.6 cm thick layers at temperatures of 50, 60, 70, and 80 C, and to fit 10 mathematical models to the experimental data. In addition, the activation energy for the drying of the residues and the thermodynamic properties were also determined. Of the models tested, the Midilli model best fitted the drying kinetics of the residues, with a coefficient of determination (R 2 ) ≥ .9960. The effective diffusivity increased with the drying temperature, ranging from 5 Â 10 À10 to 16.1 Â 10 À10 m 2 s À1 , and the activation energy (E a ) varied between 18 and 24.2 kJ mol À1 , with lower E a values for the peel and higher values for the seeds.Gibbs free energy variation increased with increasing temperature and was considered a nonspontaneous process, while the enthalpy and entropy decreased. Practical ApplicationsThe use of the data presented here for the drying kinetics and thermodynamic properties provides support for the use of the dried trapi a residues (previously discarded) in the production of new foods, due to knowledge of the processing time and physical behavior of the sample. The trapi a powder, rich in bioactive compounds, could be incorporated into various food formulations in the bakery and yogurt segments, among others. | INTRODUCTIONTrapi a (Crataeva tapia L.), which belongs to the Capparaceae family, is a fruit known by various names such as pau-de-alho, cabaceira, tapi a, among others. It is part of the Caatinga biome in the northeast of Brazil and can grow to up to 12 m in height, with a dense, rounded canopy. The trapi a fruit is round and the pulp is fleshy, edible and white in color. This species also occurs in other regions of Brazil (Minas Gerais, São Paulo, and Mato Grosso) and in other Brazilian biomes (Pantanal and Mata Atlântica) (Lorenzi, 2009). Due to the high moisture content, the fruits are highly susceptible to biochemical and microbiological deterioration. Reducing the moisture

Foaming characteristics and impact of ethanol pretreatment in drying behavior and physical characteristics for avocado pulp powder obtained by foam mat drying

“…The effect of the drying temperature on the effective diffusivity was evaluated using an Arrhenius‐type equation, which described the relationship between the activation energy and the speed at which the reaction occurred (Moura et al., 2021).…”

Foam mat drying kinetics of jambolan and acerola mixed pulp

“…The drying constant k can be used as an approximation to characterize the temperature effect, tending to increase with it, since high temperatures lead to higher drying rates, reaching the equilibrium water content faster. An increase in the drying constant (k) was also observed with increases in drying temperature (50-80 °C) for the Midilli, Diffusion Approximation, Henderson & Pabis, and Newton models for the trapiá peel residues (Moura et al, 2021). Parameter n has a moderating effect on time and corrects the likely errors resulting from the neglect of internal resistance to water transfer (Mendonça et al, 2019).…”

“…With the calculation of the water content ratio, curves of drying kinetics were plotted, represented by the water content ratio (dimensionless) as a function of drying time (min). For the selection of the most suitable models for the description of the foam mat drying process, 10 equations were fitted to the drying data (Table 1) frequently used to represent the drying kinetics (Moura et al, 2021;Omolola et al, 2019). The non-linear regression models using the Quasi-Newton estimation method were fitted using the computer software Statistics version 7.0.…”

Germinated seeds of three Cucurbita varieties: Physical characteristics, minerals profile, and drying behavior

“…Corrêa, Oliveira, Oliveira, Botelho, and Goneli (2017) in rice drying reported a reduction in enthalpy from 48.47 to 48.13 kJ/mol between temperatures of 35 and 75°C. Moura et al (2021) observed a reduction in enthalpy from 15.50 to 15.25 kJ/mol in bark and 21.52 to 21.27 kJ/mol in trapia seed.…”

“…Increased energy of Gibbs in agricultural products is reported in the literature by , Botelho, Granella, et al (2015), Cagnin et al (2017), Oliveira, Oliveira, Resende, and Silva (2018), and Moura et al (2021 in sorghum grains, garlic, mesocarp of baru fruits, and trapiá leavings, respectively.…”