January 28, 2010

Dairy-based package wraps seen as new alternative

Food-packaging products made from dairy ingredients could provide a viable alternative to petroleum-based packaging products.

According to an Agricultural Research Service (ARS) study, most food packages are made of multilayer films that are thin, continuous sheets of synthetic polymers.

However, consumers and food retailers are concerned about the waste generated during the manufacture of such packaging. Many, it seems, are interested in replacing petroleum-based packaging with bio-based packaging.

The ARS study focuses 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.

Due to 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-vapour-barrier properties.