Feb 16 2007
Cheese, meat, orange juice – most foods are encased in plastic packaging to ensure hygiene when they cross the counter. Bottles, juice cartons and plastic films contain additives to make them strong and durable, but these additives can migrate into the foods. A new mathematical model determines how many of these are later present in the food. The system was developed by researchers at the Fraunhofer Institute for Process Engineering and Packaging IVV, together with nine industrial enterprises participating in the EU project FOODMIGROSURE.
It is complex to determine how many packaging additives find their way into foods: Random food samples have to be specially prepared and subjected to chemical tests in a laboratory. To simplify these analyses, testers usually replace the foodstuffs by legally prescribed food simulants such as olive oil and mixtures of water with acetic acid or alcohol. »However, we have found that it is not usually possible to draw conclusions about solid foods on the basis of results obtained with liquid food simulants,« says IVV project coordinator Dr. Roland Franz. »In many cases the contamination of the foodstuffs is higher than hitherto assumed, and that necessitates costly product recalls.«
The new procedure yields reliable data. The researchers based their mathematical model on investigations of genuine foods rather than food simulants. These analyses were performed by all ten of the enterprises involved – resulting in the world’s only systematic collection of such data. »We developed various models on the basis of these data. One shows how the additives move about in the plastic. Another shows how many of these substances migrate from the plastic packaging material into the food, the cheese for instance, at the contact surface. A third model describes how the migrants disperse in the food itself,« Franz explains. The researchers devised a formula to summarize these models: It takes into account not only the structure of the foodstuff, such as its fat content and consistency, but also the type of plastic packaging material used, the various additives and the average quantity of this foodstuff actually eaten by consumers. The same formula can thus be used on one occasion to calculate how many packaging additives are present in cheese, and on another occasion to do the same for meat or orange juice. The cost of computer-assisted testing is much lower than for a laboratory test, and the results are far more accurate. Franz estimates the savings at a factor of between a hundred and a thousand.