Develop biopolymers for packaging applications.

Biopolymers are polymers generated from renewable natural sources. They are often biodegradable and not toxic to produce. They can be produced by biological systems--microorganisms, plants and animals--or they can be chemically synthesized from biological starting materials, such as sugars, starch, natural fats or oils.

Biopolymers are an alternative to petroleum-based polymers. (Bio)polyesters have properties that are similar to traditional polyesters. Starch-based polymers are often a blend of starch and other plastics. The biodegradability of biopolymers and other plastic properties strongly depends on the polymer's structure. By changing the structure, you can alter these properties.

In the near future, you may find hard cheeses packed in new biopolymers that will extend the shelf life of the product. Substituting fossil plastic materials with renewable biopolymers will benefit the environment and at the same time improve the utilization of agricultural by-products.

The new biopolymers may be based on such proteins as casein; on carbohydrates, such as starch, cellulose or chitosan; on lipids; and also on polymers made from surplus monomers produced on the agricultural front. They also might be based on polylactate (PLA) and bacteria, such as poly 3-hydroxy-butyrate (PHB).

European scientists are covering these fronts as they develop new packaging materials for hard cheeses. They are developing a new proactive packaging material based on PLA, and are incorporating oxygen scavengers and preservatives that have been encapsulated in cyclodextrins. Their aim is to reduce cheese oxidation--the development of rancid tastes--and the surface growth of molds.

The investigators expect to increase the shelf life of hard cheese from a range of two to three months to nine months. They also want to produce the new materials on a pilot scale. They intend to demonstrate, through an environmental impact assessment, the economical and environmental benefits. Some of the scientists had been engaged in other research in which they reviewed the production and application of bio-based packaging materials for the food industry.

Further information. Grete Bertelsen, Center for Advanced Food Studies (LMC-KVL), The Royal Veterinary and Agricultural University, Rolighedsvej 30, DK-1958 Frederiksberg C, Denmark; phone: [phone]; fax: [phone]; email: [e-mail].