NEW YORK and HAIFA, Israel -- 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 and professor 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 explains.
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.
The 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.
Source: American Technion Society