New plant-based, antimicrobial, spray-on coating keeps food fresh
Plastic wraps and containers may be great at preserving food, but they generate huge amounts of waste that can end up in the environment. Researchers at Harvard and Rutgers have developed a new plant-based, antimicrobial coating that can be sprayed onto food to keep it fresh, and is easily washed off before consumption.
The new coating consists of biopolymer fibers, which are laced with naturally occurring antimicrobial agents including thyme oil, citric acid and nisin. This helps the material fight off microbes like E. coli and listeria, preventing food spoilage and contamination. When it’s time to eat, the coating can be easily rinsed off with water.
The team says that the material can be produced at scale relatively easily, using a process called focused rotary jet spinning. Then, it can be spun out of a heating device that the team likens to a hair dryer, and applied to foods of all shapes and sizes, including fruit, vegetables and meat.
In tests, the team found that the coating can extend the shelf life of avocados by 50 percent, and even helps prevent bruising. And if it does get into the environment, the team found that it degrades in soil in as little as three days.
This isn’t the first time scientists have developed environmentally friendly food coatings to replace plastics. Other teams have experimented with films made of shrimp shells or spider silk, packaging made of milk proteins, or edible coatings made of pectin. All of these ideas, and this new one, have an important commonality – they’re made from waste products.
“What we have come up with is a scalable technology, which enables us to turn biopolymers, which can be derived as part of a circular economy from food waste, into smart fibers that can wrap food directly,” said Philip Demokritou, corresponding author of the study. “This is part of new generation, ‘smart’ and ‘green’ food packaging.”
The research was published in the journal Nature Food.
Source: Rutgers University