Microstructure and Release Behavior of Alginate-Natural Hydrocolloid Composites: A Comparative Study

Area of Science:

• Food Science and Technology
• Materials Science
• Chemical Engineering

Background:

• Sodium alginate (ALG) is widely used for microbead encapsulation.
• The influence of various natural hydrocolloids on ALG-based microbead properties requires further investigation.

Purpose of the Study:

• To investigate the impact of combining sodium alginate (ALG) with different natural hydrocolloids on the microstructure and tartrazine release behavior of microbeads.
• To evaluate encapsulation efficiency and release kinetics of tartrazine within alginate-based composite microbeads.

Main Methods:

• Microbeads were prepared by extruding tartrazine-containing solutions (0.2% w/v) of ALG combined with carrageenan (CAR), locust bean gum (LBG), acacia gum (ACA), pectin (PEC), or carboxymethyl cellulose (CMC) into CaCl2.
• Encapsulation efficiency, microbead size, surface morphology, and tartrazine release kinetics were analyzed using various models.

Main Results:

• Encapsulation efficiency was highest in ALG-CAR (74%) and ALG-CMC (78%) microbeads.
• Microbead size varied (2.07–3.48 mm), with ALG-ACA showing the smallest diameter.
• The Higuchi model best described tartrazine release, exhibiting pseudo-Fickian behavior, with slower release from ALG-ACA and faster release from ALG-LBG.

Conclusions:

• The incorporation of natural hydrocolloids significantly modifies the microstructure and tartrazine release dynamics of alginate-based microbeads.
• Specific hydrocolloids like CAR and CMC enhance encapsulation efficiency, while ACA and LBG influence release rates.
• Findings offer valuable insights for optimizing alginate-based microbead formulations in food and pharmaceutical applications.