Cellulose and Unconventional Polysaccharides in Sustainable Edible Films and Coatings: Recent Advances in Properties and Functional Performance

Due to high waste production, demand for sustainable packaging has increased, leading to growing interest in new compounds for edible films and coatings. Among the most promising are polysaccharides from unconventional sources and cellulose derivatives, which form films with good mechanical and barrier properties, making them attractive alternatives to plastics in the food industry. Although several reviews have addressed edible films based on cellulose derivatives or unconventional polysaccharides, comprehensive analyses integrating the physicochemical, mechanical, and barrier performance of both material classes remain limited. This review addresses that gap by comparing studies on the physicochemical, thermal, mechanical, and barrier properties of films made from cellulose derivatives, and from konjac glucomannan, locust bean gum, Opuntia ficus-indica mucilage, chia mucilage, and cassava starch. Beyond summarizing the literature, it critically compares the advantages, limitations, and research gaps of these materials and evaluates how structural modifications and additives affect their stability and performance. Findings indicate that incorporating unconventional polysaccharides into cellulose-based matrices improves mechanical strength and reduces water vapor permeability. Future research should focus on the rational design of multicomponent matrices and on the coupled influence of thermal behavior on mechanical flexibility, storage stability, and scale-up.