Most food packages are made of multilayer films that are thin, continuous sheets of synthetic polymers. But consumers and food retailers are concerned about the waste generated during the manufacture of such packaging. To address that concern, scientists at the Agricultural Research Service Eastern Regional Research Center in Wyndmoor, Penn. have found that food-packaging products made from dairy ingredients could provide a viable alternative to petroleum-based packaging products.
Scientists are working to develop strong, biodegradable dairy-based films that are better oxygen barriers than petrochemical-based films. ARS scientist Peggy Tomasula has been focusing on films made from dairy proteins, with an emphasis on those based on casein and whey, the major proteins found in milk. It also covers research efforts to improve the proteins' mechanical and barrier properties so that these natural materials eventually could be used in a variety of future applications.
As a dairy ingredient, casein shows good adhesion to different substrates. But while casein is an excellent barrier to oxygen, carbon dioxide, and aromas, it is a weak barrier to moisture. Because the water-soluble nature of those proteins poses a challenge, much of the research on edible casein films to date is directed toward improving their water-vapor-barrier properties.