Evaluation of the Adsorption and Desorption Dynamics of Beet Juice Red Dye on Alginate Microbeads

Anamaria Birkić,Ana Jurinjak Tušek,Jasenka Gajdoš Kljusurić,Davor Valinger,Tamara Jurina,Maja Benković

doi:10.3390/gels8010013

Abstract

The use of alginate microcapsules has often been mentioned as one of the ways to remove dyes from waste solvents, water and materials from the food industry. In addition, alginate can be used as a wall material for the microencapsulation of food dyes and their further application in the food industry. The aims of this study were to: (i) determine the effect of the alginate concentration (1, 2, 3 and 4%) on the ability of the adsorption and desorption of natural beetroot red dye and (ii) evaluate the kinetic parameters of the adsorption and desorption process, as well as the factors affecting and limiting those processes. According to the obtained results, the viscosity of alginate solutions increased with an increase in the alginate concentration. Based on k2 values (the pseudo-second order kinetic rate constant), when a more concentrated solution of alginate was used in the adsorption process, the beads adsorbed a smaller amount of dye. Furthermore, based on the values for n derived from the Korsmeyer–Peppas model, the dye release rates (k) were higher for beads made with lower alginate concentrations, and this release was governed by a pseudo-Fickian diffusion mechanism (n values ranged from 0.2709 to 0.3053).

Highlights

Dynamics of Beet Juice Red Dye on Encapsulation is defined as a process of confining active compounds within a matrix to achieve one or more desirable effects such as the immobilization, protection, stabilization, controlled release and alteration of a product’s properties [1]
The aim of this research was to determine the influence of the alginate concentration on the adsorption and desorption processes of natural red dye from alginate beads, as well as to determine the kinetic parameters and the limiting factors of the adsorption and desorption processes
The difference in the final amount of the released dye can be seen in the dependence on the alginate concentration of the beads: beads with higher alginate concentrations released a lower amount of dye per gram of beads due to higher mass transfer restrictions

Summary

Introduction

Dynamics of Beet Juice Red Dye on Encapsulation is defined as a process of confining active compounds within a matrix to achieve one or more desirable effects such as the immobilization, protection, stabilization, controlled release and alteration of a product’s properties [1]. In order to produce microcapsules with desired characteristics, it is necessary to select a suitable microencapsulation method and optimize the process conditions. The correct selection of wall material is very important, because it affects the efficiency of the microencapsulation process and the stability of the produced microcapsules [3]. Used materials are natural or synthetic polymers such as proteins, carbohydrates and gums. One of the most commonly used polymers is alginate, a natural linear polysaccharide composed of alternating blocks of 1–4 linked-L-guluronic and

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