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Fruit Packaging Investigation

Food Packaging



Areas of Expertise

Michael Fox, PhD.



Fruit Packaging Investigation

A Packaging Company that made small polyethylene pouches for a large-scale Fruit Company that sold packaged fruit nationwide was accused of making pouches that transferred a bad odor to the fruit. The Fruit Company's strategy was to measure and compare the gas chromatography (GC) peaks coming off the:

Virgin Pouches,
Bulk Fruit, and
Packaged Fruit.

Using this strategy the Fruit Company alleged that chemicals found on the virgin pouches were transferred to the packaged fruit, but were not found on the never-packaged bulk fruit. The implication is that the chemicals are coming from the packaging and being transferred to the fruit.

The pouch consisted of an outer film and an inner film. The label was inked onto the outer film that never came into contact with the fruit. The inner film and outer film were put together with a water-based adhesive. All chemicals and films were FDA Approved Food Grade. The structure of the pouch is schematically illustrated below:

While each and every chemical used to make the package was non-toxic and approved by the FDA, the Fruit Company filed a lawsuit against the Packaging Company based on the financial losses due to the odor. All of the packaged fruit was destroyed, but not before it was returned to the Packaging Company.

Dr. Fox performed a detailed investigation using GC of the packaged fruit as well as all the individual package components one by one. Dr. Fox used stacked GC plots and mirror GC plots. For example, the mirror plot of the adhesive and the final packaged fruit is presented below and shows that the adhesive could not possibly account for all the GC peaks on the packaged fruit. Similar results were obtained for each component of the pouch.

gas chromatography mirror plot

Furthermore, a more detailed GC analysis showed that the most of the GC peaks that were appearing in the packaged fruit were also on the bulk fruit. The only difference was that the bulk fruit had been exposed to the atmosphere and the volatile chemicals had time to dissipate considerably (compared to the packaged fruit) since the fruit was originally packaged. Dr. Fox presented his finding as a stacked GC plot, as shown below:

Gas chromatography

The virgin pouch is on top, the bulk (never packaged) fruit is in the center and the packaged fruit (the subject of the complaint) is on the bottom. Note that there were even some peaks that appeared on the virgin pouch that did not appear in the packaged fruit.

The lawsuit went to trial in 2013 and Dr. Fox testified on behalf of the Packaging Company. During the trial, the expert for the Fruit Company testified that it was not unusual for packaged fruit to pick up GC peaks from the packaging. This testimony was unexpected, even by the Fruit Company. It was also clear that the Fruit Company expert could not identify any GC peak that was responsible for the odor.

When Dr. Fox was asked about the Fruit Company expert's testimony during cross-examination by the Fruit Company, Dr. Fox replied: "So what are we doing here?"

The jury found in favor of the Packaging Company on each and every count.

The Fruit Company lost on each and every count.