The Silklab at Tufts University has pioneered the use of silk as a biological solution for many technological challenges. Breaking the substance down into its fibrous protein base, they’ve incorporated it into a wide range of materials, from faux leather to optical sensors to glue that can work underwater.
One use of silk protein has already found a foothold in the marketplace: as an edible coating that helps extend the shelflife of many kinds of foods.
Silklab Director Fiorenzo Omenetto, Doble Professor of Engineering in the Department of Biomedical Engineering, said that widespread use of silk coating on fruit, vegetables, meats, and other food could mitigate food waste worldwide—and, ultimately, have broader impacts.
How does it work? First, scientists in the lab melt silk fibers into a liquid. Then they wet the surface of a given piece of food with the liquid, allowing it to dry into a very thin film—“about one fifth the diameter of your hair,” Omenetto explained.
When it dries, it’s transparent and tasteless, and it acts as a protective barrier, working both to preserve dry food, like nuts or steak, and to keep moisture in wetter food (like strawberries), while also keeping pathogens out.
The ramifications, Omenetto said, are huge.
“Across the globe, we waste more than a billion tons of food each year. Anything that can be done to mitigate that has a positive effect,” he explained. “Whether it is making it easier to preserve food in places that don’t have access to refrigeration, or adding to a food’s shelf life in a store, or keeping food fresh longer in our homes so we don’t throw it away—all those things are very important in reducing our carbon footprint.”
And the impact is already underway. Research on silk as a preservative became the basis for Mori, a company built by researchers including Benedetto Marelli, an alum of the Silklab who is now a professor at MIT. Mori has taken silk coating to an industrial scale such that it’s a product on supermarket shelves, with silk-covered spinach now being sold in major retail stores in the Northeast.
And even bigger impacts are possible, Omenetto added. “This could revolutionize global health and food safety and, importantly, generate sustainable approaches that not only can preserve the world we live in, but also offer new opportunities for manufacturing and industry.”