Safe silk technology keeps fresh fruit longer

US researchers have developed silk-wrapping technology that allows the fruit to remain fresh and succulent even when not in the refrigerator for a week.

The silk coat keeps fresh strawberries for 7 days without refrigerators. (Photo: Wikimedia Commons)

Silk is considered one of the most durable materials from nature due to its insoluble protein. Named for fibroin , this protein is known for its ability to preserve other materials when coated. It is biocompatible, biodegradable and therefore very safe to digest, according to Gizmag.

In a study published today in the journal Scientific Reports, researchers from Tufts University, Massachusetts, dipped fresh strawberries into a 1% fibroin solution. They then processed the fruit in steam under vacuum under a process known as "water heating" to create crystals on the coating. The longer the berries are baked, the thicker the outer coating of their bark.

At a thickness of up to 35 microns (0.0035 cm), the coating is still invisible to the naked eye, but is sufficiently stable to slow down respiration in the fruit and thereby prevent decay. Not only keeps the berries edible for seven days at room temperature, it also slows the banana ripening rate when it is covered with banana peel. However, the taste of processed fruit has not been evaluated.