Wrap Mine in Basil

Shoppers confronted with the "paper or plastic" question in the supermarket checkout may soon also need to decide whether they want their perishables in plain or basil wrapping.

The basil is the same popular herb used to flavor foods. But in this case, the basil is incorporated into the plastic wrapping to preserve foods. The extracts methyl chavicol and linalool ooze out of the wrapping and slow the growth of eight types of lethal bacteria including E. coli and listeria. Experiments showed the wrapping extends the shelf life of cheese and most likely of meats, fish, baked goods, fruits and vegetables.

The research was published in the Journal of Agricultural and Food Chemistry (May 21, 2003) and presented at the annual symposium of the International Packaging Research Institutes in Valencia, Spain in May 2003 by lead researcher Prof. Joseph Miltz of the Technion-Israel Institute of Technology, Faculty of Food Engineering and Biotechnology, and by Profs. K. Sonneveld, S. Bigger and doctoral student Panuwat Suppakul from the Victoria University of Technology in Melbourne, Australia.

"Basil is an ideal packaging choice because it doesn't impart its flavor to the foods since only small quantities of the extracts are needed; also, because the active chemicals come from a natural source they don't degrade into harmful byproducts," Miltz explained.

The researchers developed the idea of using basil in packaging when they read about research on adding basil to foods as a preservative. Miltz knew that bacteria that cause spoilage are found on the food's surface, so there was no reason to incorporate large quantities of the basil into the food. Instead, the researchers incorporated the basil extracts into the packaging in much lower concentrations. Later these extracts diffuse onto the surface of the food, killing the microorganisms.

"One of the biggest challenges is to find the right plastic composition to make the basil-containing wrap," Miltz said. Production of plastic wrapping is carried out at high temperatures which cause evaporation of the basil-extract molecules. Additionally, the wrap is permeable, which allows the basil extracts to escape to the outside atmosphere. To counter this, the researchers are developing a multi-layered plastic with an impermeable outer layer and porous inner walls that will limit the flow of basil molecules to the inside of the package only. Marketing of the basil wrap will follow these improvements.

This is not the first time Miltz has worked on incorporating food preservative ingredients into packaging, a technology called "active packaging." Since it is oxygen that promotes the growth of the microorganisms that create food spoilage, preventing oxygen from getting at packaged food has been a long-term goal. But oxygen cannot be be neither completely removed from the package nor prevented from leaking into it from outside.

Sachets (tea-bag like packages) containing oxygen absorbers are used in food packaging in Japan and to some extent in the Western world, "but consumers don't like a package inside a package," said Miltz. Additionally, when sachets with black iron powder were used as the oxygen absorber, some people thought the powder was pepper and spread it over the meat. The major concern is that customers, especially children, may consume it by accident.

To overcome these shortcomings, in addition to the basil wrap, Miltz is working on making the oxygen absorption compounds an intrinsic part of the wrapper.

ABOUT THE TECHNION-ISRAEL INSTITUTE OF TECHNOLOGYThe Technion-Israel Institute of Technology is Israel's leading science and technology university. It commands a worldwide reputation for its pioneering work in computer science, biotechnology, water-resource management, materials engineering, aerospace and medicine. The majority of the founders and managers of Israel's high-tech companies are alumni. Based in New York City, the American Technion Society is the leading American organization supporting higher education in Israel, with more than 20,000 supporters and 17 offices around the country.