Mathematical modeling and effect of thin-layer drying and lyophilization on antioxidant compounds from ultrasonic-assisted extracted Muntingia calabura peels

Abstract

Muntingia calabura fruits are rich in bioactive compounds such as antioxidants, and the consumption of these compounds is associated with cancer prevention and aging. In this study, mathematical models were used to fit the experimental data of the Muntingia calabura peel drying kinetics, and the effective diffusion coefficient, activation energy and thermodynamic properties of the process were determined. Then, the effect of the drying temperature on the antioxidant activity and phenolic compounds of fruit peels was examined using conventional extraction and ultrasonication. Among the analyzed models, the logarithmic model was selected to represent the drying phenomenon of the calabura peel kinetics. The effective diffusion coefficient decreased by 74% as the temperature increased from 40 to 60°C, and the activation energy for liquid diffusion during drying was 23.96 kJ mol-1. The enthalpy and entropy decreased with increasing temperature, while the Gibbs free energy increased by 5% for each 10°C increase in temperature. Regarding the content of phenolic compounds and the antioxidant activity of the calabura peel, it was observed that an increase in the drying temperature had a positive effect on the conservation of the bioactive compounds, making it possible to conclude that drying at 60°C and ultrasound extraction are the most suitable approach to conduct the process.

Drying effects on Camu‐camu residue: An approach of mathematical modeling, thermodynamic properties, and color evaluation in order to obtain a natural food dye

“…Aral and Bese (2016) evaluated the convective drying of hawthorn fruits and recommended the Midilli model in their study. The same recommendation was made by Motevali et al (2016), who evaluated the drying of chamomile, and Tavone et al (2021), who assessed effects of drying on calabura bark.…”

“…In addition to meeting a significant percentage of the coefficient of determination (R 2 close to 1), the Midilli model presented the lowest values of X 2 and RMSE (close to 0) at most of the drying temperatures. Tavone and colleagues (Tavone et al, 2021) emphasize that the model suitability is related to higher values of R 2 and low values of the estimated mean error (RMSE).…”

“…The presence of different plant matrices in the sample probably means that the results of constant k did not have empirical constancy (i.e., a linear reduction of sample moisture with an increase in temperature used in the drying process). Homogeneous samples tend to present continuously increasing k values with an increase in temperature (Jorge et al, 2021; Lima et al, 2021; Tavone et al, 2021).…”

“…For the present study, the thin‐layer mathematical models most cited in the literature were selected (Azeez et al, 2017; Junqueira et al, 2017; Méndez‐Lagunas et al, 2017; Tavone et al, 2021), so Table 1 shows the models and their corresponding equations.…”

“…I G U R E 3 Experimental data of moisture ratio (MR) versus estimated data by the Midilli model on drying kinetics of camucamu pomacek values with an increase in temperature(Jorge et al, 2021;Lima et al, 2021;Tavone et al, 2021).…”