Advances in keeping other foods fresh, flavourful and safe for longer periods of time was described by scientists through the use of invisible, colourless, odourless, tasteless coatings.
Attila E. Pavlath, Ph.D., pointed out that the use of edible films has grown dramatically since the mid-1980s, when only 10 companies were in the business, to more than 1,000 companies with annual sales exceeding $100 million today.
Pavlath said that fruits and vegetables have skins that provide natural protection against drying out, discoloration and other forms of spoilage, asserting that cutting and peeling remove that natural protection, allowing deterioration and spoilage to begin.
Pavlath and his group invented the technology that enabled schoolchildren and other consumers to enjoy a new apple treat - refrigerated, packaged apple slices that last 2-3 weeks without turning brown or losing crispness.
Apples ordinarily begin to turn brown within 30 minutes after cutting or peeling. Pavlath's process involves treating freshly cut apple slices with a form of vitamin C, resulting in the first commercial product that retains the desirable characteristics of fresh apples without leaving a detectable residue.
Today's edible films, however, allow that exchange of gases and have other features that maintain freshness, flavor, aroma, texture and nutritional value. They generally provide the same protection against bacteria as the natural skin if the foods are handled under sterile conditions when they are cut in the factory, Pavlath said. Workers either spray on the films or immerse the foods in the liquid coating after cutting. The finished fruits and vegetables then go to consumers in sealed containers.