Keeping Lid on Sausage29 November 2013
The colouring in meat sandwich filling products is very sensitive to light when there is also oxygen in the pack.
The products can become discoloured if they are subjected to strong light in the supermarket, so it is very important to exclude oxygen from the pack.
Hanne Larsen, a research scientist at Nofima, has been working for several years on gas transmission in food packaging and methods of minimising the problem of oxygen access to the packaging of meat products.
This has included developing a method for testing the effect of different O2 concentrations and gas volumes on the degree of discolouration when the products are exposed to light.
It is then possible to establish a critical value for the amount of oxygen in the pack before the product begins to discolour.
When Grilstad decided to modernise the packaging of its most popular cured sausages, it was natural to involve Nofima and Dr Larsen in the job of troubleshooting and quality-assuring the new pack.
Grilstad had already performed a consumer survey, from which it emerged that the packaging was one of the products' weakest points.
The packs were difficult to open, they tore when you opened them, opening and closing functions did not work and they did not stay sealed.
If the pack is not well enough sealed, too much oxygen will get in and the product will dry out and become discoloured.
They wanted to do something about this and they found the solution in a German butter pot with a screw top.
Better Gas Barrier
The German version was not suitable for cured meats, however, and some improvements were needed.Among other things, the gas barrier that should prevent oxygen reaching the product needed improvement.
"My job was to make a theoretical assessment of Grilstad's packaging choice, so that we could minimise the risk of the product discolouring," said Dr Larsen.
As part of quality control, Dr Larsen also performed tests with varying amounts of oxygen in the packs.
"These packs were then exposed to normal supermarket lighting, so as to increase our understanding of when the product becomes discoloured and what is needed to maintain the best possible product quality from arrival in the supermarket to consumption at the breakfast table," said Dr Larsen.
Grilstad launched its new packaging onto the market on 1 September this year.