Features Business Food Safety
Killer paper for next-generation food packaging

January 19, 2011 –
Scientists are reporting development and successful lab tests of “killer paper”
– a material intended for use as a new food packaging material that helps
preserve foods by fighting the bacteria that cause spoilage.

January 19, 2011 –
Scientists are reporting development and successful lab tests of “killer paper”
– a material intended for use as a new food packaging material that helps
preserve foods by fighting the bacteria that cause spoilage.

The paper, described in
American Chemical Society’s journal, Langmuir, contains a coating of silver nanoparticles, which are
powerful anti-bacterial agents.

Aharon Gedanken and
colleagues note that silver already finds wide use as a bacteria fighter in
certain medicinal ointments, kitchen and bathroom surfaces, and even
odor-resistant socks. Recently, scientists have been exploring the use of
silver nanoparticles – each 1/50,000 the width of a human hair – as
germ-fighting coatings for plastics, fabrics, and metals. Nanoparticles, which
have a longer-lasting effect than larger silver particles, could help overcome
the growing problem of antibiotic resistance, in which bacteria develop the
ability to shrug-off existing antibiotics. Paper coated with silver
nanoparticles could provide an alternative to common food preservation methods
such as radiation, heat treatment, and low temperature storage, they note.
However, producing “killer paper” suitable for commercial use has proven
difficult.

The scientists describe
development of an effective, long-lasting method for depositing silver
nanoparticles on the surface of paper that involves ultrasound, or the use of
high frequency sound waves. The coated paper showed potent antibacterial
activity against E. coli and S. aureus, two causes of bacterial food poisoning,
killing all of the bacteria in just three hours. This suggests its potential
application as a food packaging material for promoting longer shelf life, they
note.