Microencapsulation of bioactives in cross-linked alginate matrices by spray drying

Area of Science:

• Biomaterials Science
• Chemical Engineering
• Food Science
• Pharmaceutical Technology

Background:

• Microencapsulation enhances stability, delivery, and controlled release of biomolecules, cells, and chemicals.
• Alginate is a favored encapsulation matrix due to its cost-effectiveness, biodegradability, and biocompatibility.
• Conventional alginate gelation methods (e.g., dropping into divalent cations) are difficult to scale and yield large beads.

Purpose of the Study:

• To develop a novel, scalable, and cost-effective microencapsulation method using alginate.
• To overcome the limitations of traditional alginate bead production.
• To demonstrate the efficacy of the new method for encapsulating active enzymes.

Main Methods:

• A novel spray-drying technique where alginate gelation occurs during drying.
• Gelation is triggered by base volatilization and rapid release of calcium ions.
• Particle size analysis and assessment of encapsulated enzyme activity (cellulase, hemicellulase).

Main Results:

• The spray-drying method produced insoluble alginate particles with a median size of 15-120 µm.
• Encapsulated cellulase and hemicellulase activities were not compromised by the spray-drying process.
• Enzymes retained stability during prolonged storage after encapsulation.

Conclusions:

• The described one-step spray-drying method offers a scalable and efficient alternative for alginate microencapsulation.
• This technique successfully encapsulates biomolecules while preserving their activity and stability.
• The method presents a significant improvement over costly and difficult-to-scale traditional approaches.