Investigate edible films, honey to extend shelf life.

Active packaging technologies involve interactions between the food, the packaging or coating material and the internal gaseous atmosphere to extend the shelf life of foods while maintaining their quality and safety. In general, active food packaging systems can provide several functions that do not exist in conventional packaging systems. Active functions may include the scavenging of oxygen or moisture; antimicrobial activity; and improving product edibility or biodegradability.

Edible films and coatings function as protective barriers. Because of their barrier function, coated foods may not require high-barrier packaging systems. Active ingredients and seasonings can be incorporated into edible films and coatings. They may carry antioxidants, antimicrobial agents, colorants, flavors, fortified nutrients or spices.

Edible films that fight bacteria and extend a product's shelf life are one aspect of the research focus at Clemson University (Department of Food Science and Nutrition, 224 Poole Agricultural Center, P.O. Box 340371, Clemson, SC 29634). Clemson scientists have formed the Food Packaging Films Group to explore edible films and other technologies. The group has produced packaging films from soy and corn protein. These films are being tested for digestibility. In addition to corn and soy, researchers have used polyethylene.

The investigators also have developed an antimicrobial film that is being tested against common meat-borne bacteria, such as E. coli, Salmonella and Listeria. The film contains two natural proteins that inhibit bacterial growth: lysozome and nisin. These proteins are added prior to film formation and incorporated into the packaging film.

The group also found that adding honey to turkey before cooking it increases the product's shelf life and quality by preventing oxidation. The natural qualities of honey also enhance the flavor, aroma and color of the meat. Another group of Clemson researchers is working with films produced from shrimp and crab shells. These films have exhibited some natural antimicrobial properties and other capabilities that suggest possible applications as wound dressings or other uses in addition to food packaging.

Another study involves testing the use of antimicrobial film to extend the shelf life of shredded cheddar cheese. Packaging scientists are coating low-density polyethylene packaging with cellulose containing nisin. This study will also examine the effects of different acids and coating densities on the cheese.

Further information. John McGregor; phone: [phone]; fax: [phone]; URL: www.clemson.edu/foodscience.