Biopolymers for sustainable food systems: role in stabilization, encapsulation, structuring, and packaging

The growing demand for sustainable food systems has intensified the search for alternatives to synthetic additives and petroleum-based materials, positioning biopolymers as key multifunctional solutions across food applications. Unlike application-specific reviews, this review provides an integrated perspective on biopolymers across emulsion stabilization, bioactives encapsulation, food structuring, fat replacement, and packaging, highlighting their roles in enabling functional and sustainable food systems. Drawing on recent advances, the review critically synthesizes how structure-property relationships govern the performance of biopolymers across diverse applications, while considering key functional benefits and practical limitations. In colloidal systems, biopolymers act as emulsifiers and stabilizers, where interfacial adsorption combined with bulk structuring and particle-based (Pickering) mechanisms enhances emulsion stability. In encapsulation, biopolymer matrices such as alginate, whey protein, and gum Arabic provide diffusion barriers, thereby improving the stability, bioavailability, and controlled release of bioactive compounds. Their role in food structure involves gelation, thickening, and water-binding, enabling texture design in plant-based foods and development of fat replacers that mimic the sensory and functional properties of fats in healthier formulations. In food packaging, biopolymers are used to develop edible coatings, biodegradable films, and active or intelligent systems to extend shelf life, enhance safety, and reduce reliance on conventional plastics. Additionally, the review discusses the valorization of agricultural byproducts as emerging sustainable feedstocks and identifies key challenges associated with the practical application of biopolymer-based systems in food. Thus, biopolymers represent a versatile material platform for enhancing functionality and sustainability across diverse food applications.