Edible Polyelectrolyte Complex Nanocoating for Protection of Perishable Produce

Approximately one-third of the food produced in the world is not consumed, largely due to spoilage. Fresh fruits and vegetables have a shelf life of only a few days. To reduce spoilage, packaging with a 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 a 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 a 179 μm polyester film by >10-fold. This single-step deposition process uses only water-soluble, edible biopolymers and ambient conditions, which is promising for reducing both food and packaging waste.