A recent examination of the unexpected contents of the popular kids drink was spawned by reports of consumers finding mold -- we're talking mats of fungus consisting of millions of cells -- in the beverage, Yahoo News reports.
While absolutely disgusting, the fungi probably aren't harmful to most people, said study researcher Kathleen Dannelly, associate professor of microbiology at Indiana State University.
"Probably, those of us with healthy immune systems, we could even eat that, and that wouldn't be a problem," Dannelly said, referring to the fungal mats.
However, for people with compromised immune systems, such as those with AIDS, leukemia or cystic fibrosis, the fungus may be a health concern, she added.
For instance, for those with compromised immune systems, the common fungus Aspergillus can cause lung and other infections.
Kraft, which has distributed Capri Sun since 1981, acknowledges that mold can grow in the drink, but says such reports are uncommon. "Since there are no preservatives in our drinks, mold can grow, especially in a leaking pouch," the company says on its Capri Sun FAQs website, which also boasts that each drink contains "a full serving of fruit" and "no added sugar." (Translation: Each 6-oz. pouch contains 7-10 percent fruit juice and high fructose corn syrup -- the second ingredient, after water.)
In a statement released earlier this year over a mold sighting, the company said: "If mold does occur, we completely agree that it can be unsightly and gross, but it is not harmful and is more of a quality issue rather than a safety issue."
During manufacturing, Capri Sun is heated to temperatures that exceed those used for pasteurization. But punctures in the foil packaging -- even microscopic ones -- can allow oxygen inside the package, which enables mold to grow.
Capri Sun packages have a shelf life of about a year. On its FAQs page, the company urges consumers -- over and over -- to discard leaking or damaged packages.
In the year-long study, the researchers filtered Capri Sun through special paper. In undamaged packages, they found just a few fungal cells, which grew in laboratory dishes.
In a second experiment, the scientists punctured Capri Sun packages with a sterile needle to mimic damage to the product. When left in a sterile environment for three weeks, fungal mats grew in the juice. Although they discovered five different species, the researchers are not 100 percent sure which ones they are -- and are still testing.
Mystery mold, even better!
Because Capri Sun packages aren't see-through, consumers can't tell when Capri Sun goes bad until they get a rude awakening in their straw -- or worse, their mouth. Kraft says it has tried making clear packaging, but it didn't work out in the manufacturing process.
Kraft says it will not add preservatives to the product because customers don't want it. But Dannelly said there are natural preservatives like citric acid that are not harmful and could be added.
"If you're going to have a package you can't see through, I think you need to do something," she said. Exactly.
The study has not yet been published in a peer-reviewed journal, but the researchers plan to submit the work for publication.
Capri Sun, you are no kombucha. Get it together.