Fruit and vegetables have a shelf life of a few days. And this becomes a problem, especially if your favorite salad accidentally ends up in the back of the fridge. As if to say: sometimes a moment is really enough and you lose everything.
Now things could change, though: a team of researchers from Harvard and NTU Singapore has realized a food packaging that releases useful microbes. Microbes that kill the bacteria responsible for the deterioration of fruit and vegetables. A solution that keeps food fresh much longer.
The new packaging has more than one advantage
The new material is a fantastic alternative to plastic packaging, because it is biodegradable. It is made with a process called electrospinning in which the polymeric solution-laden yarns are extracted into fibers. In this specific case the most important material is a protein called zein: It is a waste product of corn starch or oils, and comes out during the ethanol manufacturing process.
The researchers added vegetable starch cellulose and acetic acid to the zein.
Laboratory tests of the new packaging revealed that antimicrobials are released in miniscule quantities from the fibers of the material when it is exposed to increased humidity or the release of enzymes by certain microorganisms.
Thanks to its 'gradual release', the package can keep the fruit intact much longer: "even for months", say the researchers.
Fresh strawberries!
Testing the packaging on a batch of strawberries, the shelf life of the fruit has so far been seven days compared to four days in a normal plastic container.
Globalization of food supply and the need for a healthier and more ecological lifestyle make it necessary to develop biodegradable products. Smart, non-toxic packaging like this can improve food safety and quality.
Philip Democritou, an adjunct professor of environmental health at Harvard Chan School
