Smelling Peppers and Pout Submitted to Convective Drying: Mathematical Modeling, Thermodynamic Properties and Proximal Composition

Rodrigo Leite Moura; Rossana Maria Feitosa de Figueirêdo; Alexandre José de Melo Queiroz; Francislaine Suelia Dos Santos; Antônio Gilson Barbosa de Lima; Pedro Francisco do Rego Junior; Josivanda Palmeira Gomes; Wilton Pereira da Silva; Yaroslávia Ferreira Paiva; Henrique Valentim Moura; Eugênia Telis de Vilela Silva; Caciana Cavalcanti Costa; Mailson Gonçalves Gregório

doi:10.3390/foods12112106

Smelling Peppers and Pout Submitted to Convective Drying: Mathematical Modeling, Thermodynamic Properties and Proximal Composition

Foods. 2023 May 24;12(11):2106. doi: 10.3390/foods12112106.

Authors

Rodrigo Leite Moura¹, Rossana Maria Feitosa de Figueirêdo², Alexandre José de Melo Queiroz², Francislaine Suelia Dos Santos², Antônio Gilson Barbosa de Lima¹, Pedro Francisco do Rego Junior³, Josivanda Palmeira Gomes², Wilton Pereira da Silva², Yaroslávia Ferreira Paiva¹, Henrique Valentim Moura², Eugênia Telis de Vilela Silva², Caciana Cavalcanti Costa², Mailson Gonçalves Gregório²

Affiliations

¹ Department of Process Engineering, Federal University of Campina Grande, Campina Grande 58429-900, Brazil.
² Department of Agricultural Engineering, Federal University of Campina Grande, Campina Grande 58429-900, Brazil.
³ Federal Institute of Education, Science and Technology of Ceará, Campus Quixadá, Quixadá 62930-000, Brazil.

Abstract

Pepper (Capsicum spp.) is among the oldest and most cultivated crops on the planet. Its fruits are widely used as natural condiments in the food industry for their color, flavor, and pungency properties. Peppers have abundant production; on the other hand, their fruits are perishable, deteriorating within a few days after harvesting. Therefore, they need adequate conservation methods to increase their useful life. This study aimed to mathematically model the drying kinetics of smelling peppers (Capsicum chinense) and pout peppers (Capsicum chinense Jacq.) to obtain the thermodynamic properties involved in the process and to determine the influence of drying on the proximal composition of these peppers. Whole peppers, containing the seeds, were dried in an oven with forced air circulation, at temperatures of 50, 60, 70, and 80 °C, with an air speed of 1.0 m/s. Ten models were adjusted to the experimental data, but the Midilli model was the one that provided the best values of coefficient of determination and lowest values of the mean squared deviation and chi-square value in most of the temperatures under study. The effective diffusivities were well represented by an Arrhenius equation, appearing in the order of 10^-10 m²·s^-1 for both materials under study, since the activation energy of the smelling pepper was 31.01 kJ·mol^-1 and was 30.11 kJ·mol^-1 in the pout pepper, respectively. Thermodynamic properties in both processes of drying the peppers pointed to a non-spontaneous process, with positive values of enthalpy and Gibbs free energy and negative values of entropy. Regarding the influence of drying on the proximal composition, it was observed that, with the increase in temperature, there was a decrease in the water content and the concentration of macronutrients (lipids, proteins, and carbohydrates), providing an increase in the energy value. The powders obtained in the study were presented as an alternative for the technological and industrial use of peppers, favoring obtaining a new condiment, rich in bioactives, providing the market with a new option of powdered product that can be consumed directly and even adopted by the industry as a raw material in the preparation of mixed seasonings and in the formulation of various food products.

Keywords: Capsicum chinense; Capsicum chinense Jacq.; dehydration; effective diffusivity; physical-chemical composition.

Grants and funding

This research received external funding from FAPESQ-PB/CAPES, grant number 18/2020 and CNPQ, grant numbers 308255/2022-4 and 305643/2013-4 (Brazilian research agencies).