Fabrication and Characterization of Calcium Alginate Beads with a Specially Designed Magnetic Pulse Encapsulator

Abstract

In this study, a novel encapsulator system based on magnetic field principles was developed to produce gallic acid-loaded beads with an adjustable particle size and high production capacity. A dripping device was designed and optimized using the response surface methodology with a central composite design. Alginate concentration, nozzle diameter, frequency, distance, and flow rate were selected as independent variables. Bead properties, including encapsulation efficiency, production yield, loading capacity, particle diameter, aspect ratio, circularity, sphericity, polydispersity index, span, D10, D50, and D90, values were evaluated as response variables. In vitro release kinetics of the beads were investigated. Particle shape was mainly affected by all parameters except flow rate, while size distribution was predominantly governed by the alginate concentration, nozzle diameter, and frequency. Bead morphology strongly affected the release behavior, with smaller and more spherical beads showing faster release rates. The developed system successfully produced small-sized beads with high encapsulation efficiency (up to 60.7%). These findings demonstrate the potential of the proposed magnetic encapsulation system for the efficient encapsulation of gallic acid and other water-soluble phenolic compounds. Furthermore, its adaptability to multi- or interchangeable nozzle configurations makes it suitable for pilot- or industrial-scale production.