# Effect of Biopolymer Additives on Functional Properties of Alginate-Based Composite Hydrogels

## TL;DR

This review explores how adding biopolymers to alginate improves hydrogel properties for food and biomedical uses.

## Contribution

The paper systematically compares biopolymer additives to enhance alginate hydrogels' functionality.

## Key findings

- Whey proteins, gelatin, and chitosan improve mechanical and structural properties of alginate hydrogels.
- Polymer-polymer interactions influence ionic stability and bioactive compound encapsulation.
- Design guidelines are provided for optimized hydrogel systems in food and nutraceutical delivery.

## Abstract

Hydrogels constructed from natural biomacromolecules with multifunctional properties, such as improved mechanical strength, ionic stability, biocompatibility, and ionic conductivity, are highly desirable for advanced food and biomedical applications, yet remain challenging to design. Although alginate is one of the most widely used hydrogel-forming polysaccharides due to its biocompatibility and gelation ability, its intrinsic limitations often hinder the development of hydrogels with fully optimized performance. This review provides a systematic comparison of alginate-based composite hydrogels formed with complementary biopolymers, including whey proteins, gelatin, pectin, starch, and chitosan, focusing on their synergistic effects on structural, mechanical, and functional properties. Recent studies are critically analyzed to elucidate how polymer–polymer interactions influence gel network formation, environmental ionic stability, and encapsulation performance. Particular attention is given to fabrication strategies and formulation parameters that enhance the immobilization and controlled release of probiotics, vitamins, polyphenols, and other bioactive compounds. By integrating current knowledge on structure–function relationships and processing approaches, this review offers practical design guidelines for the development of multifunctional alginate-based hydrogel systems for applications in functional foods and nutraceutical delivery.