Gellan gum-based biocomposites for agriculture and food applications

Gellan gum (GG) is a linear anionic microbial exopolysaccharide produced by Sphingomonas species, and widely recognized for its physicochemical and functional properties. Due to its non-toxicity, biodegradability, biocompatibility, environmentally-friendliness, tunable structure, functional versatility, GG has emerged as a sustainable alternative to synthetic polymers in diverse industrial applications, where it is used as a thickening agent, gelling agent, emulsifier, stabilizer, carrier for active compounds, and film-forming material. Continued development of GG-based composites is expected to further expand their industrial applicability and performance. This review briefly discusses the structure, gelation mechanism, production, and applications of GG-based materials across food, cosmetic, pharmaceutical, biomedical, environmental, and agricultural sectors, which are critically discussed based on recent advances reported in the literature. GG exhibits excellent gelling, stabilizing, emulsifying, and film-forming properties. Its gelation is governed by coil-to-helix transitions and ion-mediated crosslinking, resulting in thermoreversible gels with high clarity and stability under heat and acidic conditions. Commercially, GG exists in low-acyl and high-acyl forms, which differ in mechanical strength, elasticity, texture, and thermal stability. However, native GG is limited by weak mechanical strength, poor barrier properties and structural stability, which have been effectively addressed through blending with natural biopolymers, incorporation of nanostructures, and functional modification using bioactive compounds, resulting in improved mechanical strength, stability, and functional performance. Overall, GG-based materials are promising for sustainable food systems, smart packaging, environmental remediation, controlled drug delivery, and agricultural technologies.