Most food wrap films only act as a barrier against germs and do not actually kill them. An experimental new film does just that, and even shows food changing colors as it spoils. Plus, it’s made from avocado pits.
The material is currently being developed by a team led by Professor William Chen at Nanyang Technological University in Singapore. Bill is a busy man who has recently brought us innovations such as a food emulsifier made from beer brewing waste, an algae-based palm oil alternative, and a food tray made from chicken feathers. .
In this latest project, Chen and his colleagues processed discarded avocado seeds to extract three natural compounds from them: catechins, chlorogenic acid, and a pigment known as perseolangin.
The first two substances are known to kill harmful bacteria such as Staphylococcus aureus and E. coli by damaging the microorganism’s cell membranes. Perseolangin, on the other hand, changes color in response to changes in pH levels. These levels increase when nitrogen compounds are produced by bacteria that eat high-protein foods such as meat and fish.
Although avocado seeds provide the active ingredient in the film, the bulk of the material is made up of starch harvested from discarded durian and jackfruit seeds.
Nanyang Technological University
In laboratory tests, raw shrimp were placed in a Petri dish with pieces of film. When the shrimp started to spoil, the color of the material changed from yellow to brown, giving a warning. The important thing is that I did it at least 2 days before the shrimp themselves changed color and smell.
“By harnessing the power of nature – the antibacterial and anti-septic compounds found in discarded avocado pits – we have developed a new food wrap that could go a long way in reducing food waste. ” says Chen.
In fact, this isn’t the first movie to change color to warn of rotten food. Similar materials are being developed by scientists at MIT, the Fraunhofer Institute for Modular Solid State Technology, and the University of Strathclyde, although none incorporate avocado seed compounds.
Source: Nanyang Technological University
