Minced meat, bread, fruit juice,
and many other foods are packaged in a protective gas which extends their shelf
life. There is currently no good method to check whether the packaging has the
correct gas content. However, researchers in Lund University’s
Atomic Physics and Packaging Logistics have developed a new laser instrument
which could solve the problem. The first product is expected to be ready for
market launch later in the autumn.
“It will be the first
non-destructive method. This means that measurements can be taken in closed
packaging and the gas composition over time can be checked. This will make it
possible to check a much higher number of products than at present,” says Märta
Lewander, Doctor of Atomic Physics at Lund
University in Sweden.
Lewander developed the technique
in her thesis and now works as chief technical officer for the company
Gasporox, which is commercializing the technology.
Today, spot checks are performed
on individual samples, with the risk that damaged products could slip through.
“We hope that, in the long term,
this type of equipment could also help to stop people throwing so much food
away, because they would know that it is packaged as it should be,” she says.
The product that will be launched
in the autumn could be used to check and improve how airtight packaging is.
Gasporox estimates that within two years the method could also be used as a
means of quality control in production when products are packaged. In the
future, shops could also use it to check the shelf life of their goods.
No plastic packaging is 100%
airtight. How easily oxygen can enter depends on both the material and how well
sealed the packaging is.
“It has been shown that
part-baked bread, for example, doesn’t always meet the mark,” says Annika
Olsson, Professor of Packaging Logistics at Lund University.
The technology can measure
through almost all packaging materials.
“As long as light can pass
through then we can measure. Almost all materials allow at least some light to
pass. Even packaging that contains aluminum foil, for example some fruit juice
cartons, often has some part that is not covered by the foil,” says Lewander.
At Lund University,
research in the field is continuing. Patrik Lundin, a doctoral student in
Atomic Physics, is now focusing on measuring carbon dioxide in packaging.
“It is important to measure both
oxygen and carbon dioxide. Oxygen is most important, but there is also interest
in carbon dioxide from the industry,” says Lewander.
The development work has been
financed by several research grants from bodies including Vinnova and by
private entrepreneurs and investors. The product that is being developed by
Gasporox is manufactured by a part-owner of the company, the Norwegian company
Norsk Elektro Optikk.
How the technology works
The protective atmosphere
that surrounds the food product in the packaging usually comprises carbon
dioxide or nitrogen and contains little or no oxygen. Oxygen leads to oxidization,
bacteria growth, and decay. By shining a laser beam into the packaging and
studying the light that comes back, it is possible to see if the composition of
the gas is correct. The laser beam measures the amount of oxygen.
The laser is connected to a
handheld unit which is held against the sample. A handheld detector measures
the light that comes out of the packaging and sends a signal to a computer.
The technology is based on a
technique for measuring the gas composition of samples containing cavities. An
early application was to diagnose sinusitis, by enabling doctors at a primary
health centre to find out whether the sinuses were full of gas as they should
be. Clinical studies have confirmed that the technique works, and this
application is expected to be on the market within a year or two.