Parametrization of particle coating process with chitosan in spouted bed

Abstract

This research aimed to evaluate the main process variables effect on the coating of inert particles in spouted bed with a solution based on chitosan, and later to apply them in batch tests of anthocyanins adsorption extracted from red cabbage. For this, experimental design techniques were used to evaluate the impact of the inlet air temperature (T), spouting air relative flow (W_REL) and the flow rate of the coating suspension (Q_CS) on the process efficiency response (η). The coating experiments were conducted for a total time of 40 min and a spray pressure of 0.1 MPa. From the results obtained, the best condition for executing the recoating process was determined, with inlet air temperature of 70 °C, relative flow of spouting air of 1.7 and 4 ${\text{mL min}}^{-1}$ for flow coating suspension. This operational condition enabled process efficiencies close to 90%. The coating quality was analyzed by scanning electron microscopy (SEM) and the surface elemental composition was verified by X-ray energy dispersion spectroscopy (EDS). The process of coating inert particles with chitosan in the spouted bed provided satisfactory results, both from the point of view of process performance and in coated particle adsorption capacity.

Keywords:

• Adsorption
• anthocyanin
• drying
• experimental design
• moving bed

Additional information

Funding

The authors are grateful to the Fundação de Amparo à Pesquisa do Estado do Rio Grande do Sul (FAPERGS); as well as to Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) and to the Centro de Microscopia Eletrônica da Zona Sul (CEME-SUL) of the Federal University of Rio Grande (FURG).