Basil packaging film improves product shelf life.

Scientists at the Israel's Technion Institute of Technology and Victoria University, Melbourne, Australia, have developed a polymer-based film that incorporates extracts of the herb basil (Ocimum bacilicum). The film increases a product's shelf life and acts as an antimicrobial barrier against certain pathogens.

The film would be useful to meat and cheese processors. Two chemical extracts from basil are used, an ether, methyl chavicol (estragole) and the alcohol linalool. These have antimicrobial activity against eight types of bacteria, including E. coli O157:H7 and Listeria.

The extracts exert their antibacterial effects by means of chemical groups that attack and destroy the cell walls of the bacteria. A mixture of polymers in the film retains the antimicrobial chemicals in the film and prevents evaporation of the volatile components during film manufacture.

The basil molecules bind to the polymers, but water in the food allows the chemicals to leach away from the plastic into the food. The basil extracts do not add a basil flavor to the product. Researchers are examining different designs that would allow them to incorporate tougher, less permeable polymers on the outer surface of the film.

This would ensure that the extracts leach into the food and are not lost to the surrounding environment. Previous research had found that horseradish (wasabi) had antimicrobial activity when incorporated into packaging. However, the wasabi added flavor to products.

In addition to basil, we know that common kitchen spices--garlic, cinnamon, clove and others--can kill the most dangerous strain of E. coli. In research at Kansas State University, garlic, clove, cinnamon, oregano and sage each killed the bacteria in varying amounts. In one study, garlic killed the organism completely. None of the other 18 spices tested was successful in killing E. coli O157:H7.

Further information. Joseph Miltz, Head of Packaging Laboratory, Technion Institute of Technology, Haifa 32000, Israel; phone: [phone]; fax: [phone]; email: [e-mail].