New Insights into Green Food Preservation: “Armored” Lignin Nanoparticles as Promising Antioxidant-cum-Antimicrobial Agents

How to effectively protect lignin so that it can play a role in the field of food preservation in a long-term and stable way is a problem we need to solve. Herein, first, we used the "armor" prepared by poly(vinyl alcohol) and acrylate epoxidized soybean oil to comprehensively protect lignin through emulsion polymerization and obtained AS-lignin nanoparticles (NPs). Subsequently, a multifunctional AS-lignin NPs/ cellulose acetate (CA) membrane was obtained by implanting AS-lignin NPs into a CA fiber network via the electrostatic spinning technique. The incorporation of AS-lignin NPs in the CA matrix resulted in improved stress transfer from the CA matrix to the filler, leading to a significant enhancement of its mechanical properties. These membranes possess various properties, such as UV and visible light barriers, oxidation resistance, thermal stability, excellent oxygen barrier, water vapor barrier, and antimicrobial properties. Notably, the shelf life of fresh apples was extended by at least 3 days under ambient conditions when they were covered by these membranes. These membranes can be safely degraded in the natural environment. This means that our work introduces a novel concept of using lignin as a template to develop food preservation materials with unique properties. This approach holds great promise for creating a new generation of food preservation membranes.