Title: Sorption isotherms and drying kinetics modelling of convective and refractance window drying of feijoa slices (Acca sellowiana Berg)

Authors: Adriana María Castro Sánchez; Edgar Yesid Mayorga Lancheros; María Ximena Quintanilla Carvajal; Fabián Leonardo Moreno Moreno

Addresses: Universidad de La Sabana, Campus Universitario del Puente del Común, Km 7 Autopista Norte de Bogotá, Chía, Cundinamarca, Colombia ' Mathematics and Statistics Department, Engineering Faculty, Universidad de La Sabana, Campus Universitario del Puente del Común, Km 7 Autopista Norte de Bogotá, Chía, Cundinamarca, Colombia ' Engineering Faculty, Grupo de Investigación en Procesos Agroindustriales, Universidad de La Sabana, Campus Universitario del Puente del Común, Km 7 Autopista Norte de Bogotá, Chía, Cundinamarca, Colombia ' Engineering Faculty, Grupo de Investigación en Procesos Agroindustriales, Universidad de La Sabana, Campus Universitario del Puente del Común, Km 7 Autopista Norte de Bogotá, Chía, Cundinamarca, Colombia

Abstract: The refractance window and convective drying modelling of feijoa is important to dryers design used for the fruit preservation. This work presents the sorption isotherms and the drying kinetics of the convective and refractance window drying of feijoa slices. Feijoa was dried by convective drying at 50, 60, and 70°C, air velocities of 0.5 and 1 ms⁻¹ and by refractance window at 60, 70, 80°C, with thicknesses of 3 mm and 5 mm for both technologies. The sorption isotherms were determined at 25, 35 and 45°C. Twelve thin-layer models and the effects of the operative conditions were analysed. The most suitable models were the logistic and Midilli for both drying methods. The Peleg adsorption model adequately described the experimental data over the entire measured range of the water activity. Drying modelling and sorption isotherms can be used in process optimisation and dryers design.

Keywords: convective; refractive; thin layer; fruit; sorption isotherms; mathematical modelling; diffusivity; Midilli model; logistic model; Peleg model.

DOI: 10.1504/IJPTI.2020.109634

International Journal of Postharvest Technology and Innovation, 2020 Vol.7 No.2, pp.118 - 136

Received: 09 Dec 2019
Accepted: 24 Apr 2020
Published online: 17 Sep 2020 *

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