Optimization of Osmotic Dehydration as a Pretreatment for Solar Drying of Eggplant

Abstract

Osmotic dehydration (OD) is a technological alternative to improve the efficiency of drying processes, reducing the water content prior to heat treatment and optimizing mass transfer. In this work, the osmotic dehydration kinetics of eggplant (Solanum melongena) were evaluated in sucrose solutions at different concentrations, with the aim of identifying operating conditions that maximize water loss. Based on the kinetic analysis, the most representative treatment condition was selected for subsequent application in solar drying. The results indicated that the greatest water loss occurred during the first hour of treatment, especially in higher concentration solutions, consistent with findings reported in mass transfer studies in plant matrices. A 40% sucrose solution was selected for 1 hour as the optimal condition. Applying this pretreatment to solar drying showed an improvement in the process kinetics compared to samples without osmotic treatment. These results allow for the development of an integrated strategy to optimize combined dehydration processes in plant-based foods.