To cut down on food waste, researchers at Tufts University have developed a method of preserving perishable produce without a refrigerator. The team of researchers created a silk fibroin (which is a structural protein) solution and coated strawberries with it for a study published in Scientific Reports.

The researchers dipped fresh-picked strawberries in the solution, which is a flavorless, edible, and almost invisible substance. The longer the berries were dipped, the more silk fibroin remained on the fruits. The coating ranged from 27 to 35 microns thick.

The berries, which were coated with varying thicknesses, along with regular uncoated berries were stored in a room temperature environment. By the end of seven days, the coated berries were juicy and fresh, while the uncoated berries were definitely not something you’d want to eat. The researchers found that the strawberries coated in the silk solution stayed fresh for more than a week without refrigeration.

The silky was able to keep the fruits fresh by “slowing fruit respiration, extending fruit firmness, and preventing dehydration,” the paper’s authors write.

The solution was also tested on bananas, to test how it affects fruit that ripen after they are harvested. Similarly, the researchers found that the coating slowed the ripening.

While the silky coating did not negatively affect the texture of the strawberries or bananas, the most important factor was not studied: taste.