Application of inverse methods in the osmotic dehydration of acerola

Abstract

This work presents a study of the mass transfer of osmotically dehydrated West Indian cherry, also known as acerola. The experiments were performed by immersing the fruits in a sucrose solution at 65oBrix for 12 h at ambient temperature (27 °C), using three different fruit:solution ratios (1:4; 1:10 and 1:15 (w:w)). The kinetics of water loss, solids gain and weight reduction was determined. Effective mass diffusivity was calculated by the inverse method, using the Levenberg-Marquardt minimisation algorithm. The mathemat- ical model used to describe the physical phenomenon of osmotic dehydration was based on Fick’s Second Law, considering the fruits as geometrically perfect spheres. The influence of the fruit:solution ratio was not significant in the range of this study. Diffusivity ranged from 1.558 · 10 )10 to 1.760 · 10 )10 m 2 s )1 .