Invisible edible coatings made from gelatin might provide a new way to make sure water vapor does not wreak havoc with frozen food tastes and textures, according to new research from US Department of Agriculture scientists. Frozen foods maintain their quality if they have just the right amount of moisture - neither too wet nor too dry. However freezing can result in a loss of moisture, leading to a sub-standard product. Thin, clear coatings made from gelatin extracted from the silvery skins of seagoing fish such as Alaskan pollock can help prevent the problem, the US scientists said in research published this week. The coatings, which look something like everyday clear plastic wrap, have no seafood taste or odour, the scientists stated. Using fish gelatins for packaging is not a new concept. But the USDA studies apparently are the first to establish the effectiveness of Alaskan pollock gelatin as a barrier, they claimed. In laboratory tests, the fish gelatin proved a more effective barrier to both unwanted moisture and oxygen than films made from the traditional sources-cow and pig hides. Also, the fish gelatin would be acceptable in kosher and Halal cuisine, while the cow and pig gelatins are not, they suggest. "Besides these versatile coatings and films, fish gelatin offers an alternative to the traditional gelatins used as an ingredient in some frozen foods, for example," they stated. They suggest that if a market develops processors could find a new revenue stream from their operations. Skins left over after pollock and other fish are processed are typically ground up and dumped into the sea or processed into low-value fishmeal. "Gelatin coatings may provide a profitable and environmentally friendly alternative to this approach," they stated.