Researchers from the US Department of Agriculture’s Western Regional Research Center in California have developed a new technology to provide consumers with refrigerated, packaged apple slices that last two to three weeks without turning brown or losing crispness.
The new process involves treating apple slices with a form of vitamin C, which retains the characteristics of apples without leaving a detectable residue.
Normally, Apples turn brown within 30 minutes after cutting or peeling; however, through the use of invisible, colorless, odorless, tasteless coatings, food products can be kept fresh, flavorful and safe for longer periods, the researchers said.
These coatings comprise thin layer of edible material applied to the surface of a food product to preserve freshness.
For example, Apples lose some of their natural wax coating during washing after harvest. The thin layer of carnauba wax, obtained from the leaves of palm trees, can be used as a replacement coating.
Some of the common edible coatings include starch, alginate, carrageenan, gluten, whey and beeswax.
The overview of edible films was presented by Attila E. Pavlath and was a part of National Meeting & Exposition of the American Chemical Society (ACS).
Pavlath said the use of edible films is likely to increase substantially, especially for fruits and vegetables, as consumers seek for more foods that require minimal preparation such as cut fruit and premixed salads.
"Fruits and vegetables have skins that provide natural protection against drying out, discoloration and other forms of spoilage."
"Cutting and peeling remove that natural protection, allowing deterioration and spoilage to begin," he added.
Pavlath cited two challenges in the edible coating R&D, finding an edible coating that would make fresh-cut sliced bananas a commercial reality and developing a coating for avocados to avoid quick discoloring after they are peeled.
Image: The new process involves treating apple slices with a form of vitamin C. Photo courtesy of iStockphoto/Thinkstock.
