Approximately one-third of the food produced in the world is not consumed, largely due to spoilage. Fresh fruit and vegetables have a shelf life of only a few days. To reduce spoilage, packaging with high oxygen barrier is needed, but plastic packaging also creates waste. In this study, edible polyelectrolyte complexes consisting of chitosan (CH) and pectin (PT) are deposited onto fresh fruit to extend shelf life. This unique edible coating imparts high gas barrier and high transparency that can slow the ripening of bananas and browning of apple slices. A 1.5 µm thick CH/PT coating reduces the oxygen transmission rate of 179 µm polyester film by more than ten times. This single-step deposition process uses only water-soluble, edible biopolymers and ambient conditions, which is promising for reducing both food and packaging waste. Flame retardants mitigate the threat of fire from inherently flammable materials responsible for sustaining a high standard of living. Although bulk flame retardants have proven effective for many years, there is now increased interest in the use of surface treatments to localize flame retardant chemistry at the exterior of a material, where combustion occurs. These water-based coatings preserve desirable bulk properties and minimize the amount of additive needed. The success of these treatments depends on the scalability, durability, and efficacy. Our work in the fields of layer-by-layer (LbL) assembly and polyelectrolyte complexation has provided new water-based coating technologies for imparting effective flame retardancy to polymeric materials (e.g. foams and textiles) using chitosan and other bio-sourced polymers.

Chitosan-based polyelectrolyte complex nanocoatings for protection of perishable produce and stopping fires

Fall 2022 abstracts, posters, and presentations will launch in mid-September.

ACS Fall 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.