A new packaging material could be used on food products

Jun 28, 2007 14:49 GMT  ·  By
A continuous biodegradable protein film begins to form using the new ARS film-making process.
   A continuous biodegradable protein film begins to form using the new ARS film-making process.

Everybody knows dairy products, some people love them, some people don't. But for the healthy food addicts, there are some good news: future food products may actually be made of dairy byproducts, thus bringing the milk out of the cup and into the cup itself.

A new technology - developed by research leader Peggy M. Tomasula and her colleagues at the ARS Eastern Regional Research Center's Dairy Processing and Products Research Unit in Wyndmoor, Passadena - is using dairy byproducts to create a thin, water-resistant film, that could be used as an edible coating for food products.

The product is made by combining casein, a milk protein, with glycerol, a byproduct of biofuel production, and water. Tomasula said that carbon dioxide is a good solvent in the process of isolating dairy proteins from milk, more environmentally friendly than chemicals like acids that can be difficult to dispose of.

Carbon dioxide (CO2) itself is a byproduct of the glucose fermentation process used for producing ethanol, a clean alternative fuel. It's precisely this CO2 that gives the film the resistance to water and its biodegradability.

The films could find commercial applications in no time, since they are transparent, glossy and completely edible. Also, they could extend the shelf life of many foods, protect products from damage, prevent exposure to moisture and oxygen and improve appearance.

The production process consists in dissolving CO2 into the milk, which decreases its pH level and causes the casein to form particles of a substance known as CO2-casein, the size of which can be decreased to improve the ability of the film to block moisture and to increase its glossiness.

Oxygen is kept out by coating a low-density polyethylene film with the CO2-casein, meaning that this new packaging material is also airtight, in addition to being waterproof, which makes it ideal for a variety of food products.