Edible milk protein skin opens new packaging opportunity

The new process developed by the US Agricultural Research Service (ARS) to make the packaging could open up a new opportunity for dairy makers looking to present their products in edible,biodegradable, natural packaging.

The edible film locks in moisture, and can be used to coat dairy food products, such as cheese, or function as part of a laminate in packaging for cottage cheese or yogurt, ARS scientists suggest.

Flavorings, vitamins or minerals could be added to enhance flavor and nutrition.

The ARS scientists say their process makes it possible to produce a continuous roll of casein film. Casein is a milk protein that is the chief nutritional ingredient in cheese.

Casein is also used in non-food products including adhesives, finishing materials for paper and textiles, and paints.

The casein films could serve as stand-alone sheets or as thin coatings that form a barrier to outside substances while protecting a product from damage or contamination, ARS suggests.

Under the process casein is first extracted from milk with high-pressure carbon dioxide (CO2), a method developed by Peggy Tomasula, an ARS researcher.

She found that if this casein is mixed with water and glycerol and left undisturbed to dry, it results in a water-resistant, flexible, film-like material. ARS holds a patent on the method Tomasula developed.

Michael Kozempel, a chemical engineer, has also developed a continuous pilot plant process to produce the film.

He found a suitable belt material and feeding mechanism so that the solution can be uniformly spread and dried to form a film that is readily removed from the belt. The process can be modified for other proteins, ARS stated.

ARS has filed a patent application on the continuous production process Kozempel has developed, and says it is looking for business partners to bring the product to the market.