Starch-based biocomposite films and coatings in paper-based food packaging: a review

Many fossil fuel-derived plastic polymers are causing environmental pollution by microplastics, and are accelerating global warming because they are carbon positive, calling urgently for alternatives such as biopolymers made from modern biomass. Here, I review starch-based biocomposites with emphasis on natural components, applications for paper coating, challenges, and manufacturing. Natural components include polysaccharides, proteins, clay, and metals. Challenges comprise biodegradability, production cost, printing and labeling, policies, the lack of homogeneity and of life cycle assessment, and mismatched expectations of academia and industry. In particular, starch-based packaging has drawbacks that make it unsuitable for food packaging, including poor thermal resistance, barrier properties, and mechanical properties. I observe that the ratio of amylose and amylopectin impacts the barrier and mechanical properties of starch-based films.