Measuring aromas for optimized packaging, Solutions!, Online Exclusives, December 2004

MEASURING AROMAS FOR OPTIMIZED PACKAGING

How well-sealed is a packaging material, and how much aroma is let out-or in? The answer can determine how much flavoring needs to be added to a food before packaging, or how the contents of packaging are affected by being stored in various environments. At Iggesund Paperboard’s Laboratory for Sensory and Chemical Analyses in Strömsbruk, Sweden, a unique measuring device is being developed to measure how much aroma is penetrating a material.

"Traditionally people have mostly looked only at how oxygen, water and carbon dioxide act in combination with different packaging materials, but now we can measure practically all aromas if they are available in a solid or liquid form," explained Gunnar Forsgren, technical manager at the lab. "We can also measure the effect of four different aromas at the same time."

The Laboratory for Sensory and Chemical Analyses is a resource within Iggesund Paperboard that is used both for in-house quality control and on behalf of external customers. The laboratory is accredited for sensory analyses, which means that a Swedish government agency, the Swedish Board for Technical Accreditation (SWEDAC), supervises the laboratory’s work and guarantees its quality. In turn, this means that the measurements are accepted by most countries. Iggesund Paperboard is the only European paperboard manufacturer to have such an in-house resource.

Optimize packaging
"The new equipment is particularly valuable if one wants to optimize the odor and taste properties of food packaging," Forsgren added. "It is now possible to study in detail exactly what effect a given combination of aromas has on paperboard material with different coatings-and that will result in a better basis for decision making.

"In all honesty, there is a great deal of belief and not much knowledge when it comes to how various aromas behave in these materials. And that is primarily because there have not been good measuring methods," he said. Forsgren predicts that the method will be extremely useful to Iggesund’s specialists at Ströms Bruk, who are developing coated paperboard for different purposes.

Paperboard from Iggesund Paperboard is used to package sensitive products such as food, confectionery, medicines and beauty products. Like other packaging materials, paperboard affects the smell and taste of the products by both giving off and absorbing aromas.

This effect need not be negative. Odors that come from packaging can have a positive effect, just as storage in wooden barrels is used to add flavor to wine and whisky. There are examples of foodstuffs which have changed in flavor when the packaging manufacturer changed printing inks, materials or their composition. That is why it is important that a supplier of packaging materials can guarantee stable properties over time. It is with these facts in mind that Iggesund Paperboard has systematically built up its expertise.

Humans are best
The only measuring instruments which are sufficiently accurate are the human senses of smell and taste. Equipment does exist which can determine with good precision the amounts of many substances given off by the packaging-equipment such as the gas chromotographer and the mass spectrometer. But when it comes to measuring the total impression and how a product is affected, there are no useable instruments.

"The concentrations are at the ppt level," said chemist Torgny Ljungberg. (One ppt is one part per trillion (0.000000000001); not even the much talked-about electronic "nose" can detect such low levels, although the human nose can.) "We use an external panel of about 25 people who have no ties to Iggesund Paperboard."

The panel includes all kinds of people-blue-collar workers, teachers, nurses-who all have one thing in common. They have been chosen after tests indicated their heightened sensitivity to taints and odors from paperboard packaging.

Each panelist is trained for up to a year before participating in actual tests. The actual analysis work is reminiscent of wine tasting, with one important exception. Before the tests, the panel is calibrated by letting its members sniff at and taste known substances. The entire panel’s results are also regularly validated by being compared with results from other sensory laboratories.

Experience shows that these trained people can differentiate nuances in smell and taste which cannot be detected by measuring instruments. The analyses demand complete concentration. It is not possible, for instance, to do the tests on the day before big celebrations or before major public holidays. For the same reason, managers are not suited to the job. They have too much else to think about.

Another important ingredient is continuity. Most panel members have many years of experience in sniffing at paperboard and tasting packaged products. From this point of view the laboratory is perfectly located, far from the stress of the big cities.

Impartial and trustworthy
While experience shows that sensory tests have a high level of reliability if they are carried out correctly, their credibility is a more difficult issue. A numerical measurement is seen to be more exact, especially when there can be opposing opinions on an issue. That is why Iggesund Paperboard arranged for its sensory tests to be accredited.

Accreditation is the most stringent form of quality assurance and is based on the EN 45001 standard. In contrast to ISO 9000, for example, EN 45001 requires a level of quality that is guaranteed by a government agency. In Sweden this is the Swedish Board for Technical Accreditation (SWEDAC). When the tests are accredited, the owner of the facility loses influence over them. SWEDAC’s crowned symbol guarantees that the tests are done objectively using approved and proven methods.

"It is a credibility issue. Iggesund Paperboard’s customers must be able to rely on the laboratory providing impartial conclusions and not serving any special interests," Ljungberg and Forsgren explained.

"The new equipment makes it possible to study in detail exactly what effect a given combination of aromas has on paperboard material with different coatings," say Gunnar Forsgren and Torgny Ljungberg of Iggesund Paperboard’s Laboratory for Sensory and Chemical Analyses.