Emerging trends in plant biopolymer engineering: Green extraction, functional modification, and bioengineering applications

The increasing environmental burden associated with petroleum-based polymers has accelerated the development of sustainable material alternatives derived from renewable resources. Plant-based biopolymers, including polysaccharides, proteins, phenolics, and polyesters, have emerged as promising candidates due to their abundance, biodegradability, and versatile functional chemistry. This review provides a comprehensive and critical synthesis of recent advances in plant biopolymer engineering, with particular emphasis on green extraction technologies, structure–property–performance relationships, and emerging application domains. The transition from conventional chemical extraction methods to environmentally benign approaches such as enzyme-assisted processing, deep eutectic solvents, ionic liquids, and ultrasound-assisted techniques is examined in terms of efficiency, scalability, and environmental impact. Furthermore, the interplay between molecular architecture, supramolecular organization, and macroscopic properties, including mechanical strength, thermal stability, barrier performance, and biodegradability, is systematically analyzed to establish design principles for application-specific material development. Recent progress in functionalization strategies, including chemical, physical, and biological modifications, is also discussed as a means to overcome intrinsic limitations such as moisture sensitivity and poor processability. The performance of plant-derived biopolymers is critically evaluated across key application areas, including sustainable packaging, biomedical systems, structural composites, environmental remediation, and energy storage, with direct comparison to conventional synthetic materials. Despite significant advancements, challenges related to large-scale processing, material consistency, and techno-economic feasibility persist. Future research directions are proposed, focusing on integrated biorefinery approaches, hybrid material systems, nanostructuring, and standardized performance benchmarking to facilitate industrial translation. Overall, this work provides a unified framework for advancing plant-based biopolymers toward high-performance, sustainable materials within a circular bioeconomy.