Thermodynamic model of Ca(II)-alginate beads drying by spectrophotometry

Abstract

The purpose of this work was to study the drying process of Ca(II)-alginate beads with/without sucrose, monitored by infrared thermography (IRT), in order to describe the critical points and the transformations suffered by the systems. Beads were obtained by the drop method and the drying process was performed at 40 ºC and 1.5 m/s. IRT was measured by a thermal imager Optris PI® 160. Mass, aw, xw and volume were also obtained. It was demonstrated that IRT is a good monitoring tool, able to analyzed heat transfer in colloidal systems. A thermodynamic model able to predict the mechanical phenomena of the beads throughout drying process has been developed. Keywords: encapsulation; thermodynamic; spectrophotometry; drying; beads