Lignin as a sustainable and functional material for active food packaging applications: A review

Abstract

The growing demand for sustainable packaging solutions has led to extensive research into eco-friendly materials, with lignin emerging as a promising candidate for active food packaging applications. This review comprehensively explores the multifaceted role of lignin in the area of sustainable packaging. Lignin, the second most abundant plant-based polymer on Earth, is an economical and renewable resource that can be utilized for sustainable food packaging applications. Lignin is rich in polyphenols that provide excellent functionality such as antioxidant activity, antibacterial activity, ultraviolet radiation protection properties, and biocompatibility. Therefore, it has been widely used as a multifunctional additive in food packaging polymers to prepare flexible films and coating formulations. The recent advent of lignin nanoparticles has improved the efficacy of lignin as a multifunctional filler in food packaging. Some reports also indicate that lignin hydrogels are suitable as stand-alone food packaging or coating materials. Despite advances in research on these multifunctional polyphenol macromolecules, there have been some knowledge gaps, especially with regard to ambiguities in their exact structures arising from different isolation methods. Although several review articles discuss the suitability of lignin for food packaging applications, there are no elaborate reports that discuss the impact of lignin structure on physicochemical and functional properties precisely in the context of food packaging. This review explores information about these structural ambiguities along with their impact on the properties of lignin from a food packaging perspective. This information supports further research into the production of bio-derived materials as cleaner, more economical, more versatile and more sustainable materials for applications in active food packaging.