Production, Characterization, and Application of the Biopolymer Alginate in the Food and Pharmaceutical Sectors: A Review

Abstract

Alginate, a naturally occurring polysaccharide isolated mainly from the cell walls of brown algae (Phaeophyceae), has attracted sustained research interest for its gelling, thickening, and stabilizing properties. However, the available literature on alginate remains scattered across disciplines, limiting its usefulness to researchers and industry. This review consolidates current knowledge on the production, structural characterization, and applications of alginate, with particular emphasis on the food and pharmaceutical sectors. Alginate can be obtained from brown algae or from bacterial fermentation, notably by Pseudomonas species and Azotobacter vinelandii, and its fine structure is routinely resolved using simple biochemical assays alongside spectroscopic and chromatographic techniques. In food systems, alginate functions as an emulsifier, stabilizer, and texture modifier; its antioxidant activity and capacity to encapsulate cells, DNA, nutrients, and microorganisms support the controlled release of flavours, minerals, and bioactive compounds. In pharmaceutical applications, alginate regulates the viscosity and stability of formulations and is used in wound-healing gels, dental impression materials, heavy-metal chelation, tissue engineering, controlled drug delivery, 3D bioprinting, and cell immobilization. Collectively, the evidence reviewed here confirms alginate as a versatile, biocompatible biopolymer of substantial and expanding industrial relevance.