Just when you thought you had recycling all worked out, here’s something to feast your taste buds on.
Scientists in the US and Scotland are turning plastic waste into food and believe it could be the new weapon in the war on plastic.
When it comes to waste, Australians are considered among the worst offenders in the developed world.
Roughly 15,000 bottles and cans are thrown away every minute of the day - enough rubbish to stretch across Australia in just a day.
Worldwide, only about 20 per cent of all plastics are recycled.
But could we simply eat all our problems away?
Professor Veena Sahajwalla, from the University of NSW's Centre for Sustainable Materials Research and Technology (SMaRT@UNSW), says finding a useful second life for plastic is the key.
“I think one of the things that we can all agree on is we all do generate a lot of waste, " Professor Sahajwalla said.
"So if we are going to generate waste, and if this is part of our lives, we have to see this as a valuable resource that can be converted into safe and useful products for our people.”
Turning plastic into an edible protein
Scientists in the US are cooking up an edible protein made from plastic and Associate Professor Steve Techtmann from Michigan Tech University says it’s not that different from the food we already consume.
“Most of the food we eat is just cells, " he said.
"We eat plants and animals and we’re eating their cells. Why couldn’t we eat bacterial cells or yeast cells?
“So what we’re trying to do in this project is to take plastic and feed it to bacteria, use the bacteria to break the plastic down and then recover the bacteria as a potential food supplement, in the same way that you might use nutritional yeast or Vegemite.”
Here’s how it works: The plastic is broken down into small pieces and then heated until it turns into a liquid resembling petrol. That liquid is put into a tank filled with bacteria that feast on it.
Once the bacteria has done its thing, what’s left behind looks like a paste which is then dried down into a powder. The hope is that this powder can then be eaten and also have enough nutritional value to be used as a supplement.
Soft plastics like shopping bags and biscuit packets are shredded before being turned into other products at Replas. Source: Supplied / Supplied: Replas
Could plastic waste be the solution to world hunger?
Professor Techtmann says food made from plastic could potentially be one solution to world hunger and disaster relief efforts.
“What we are thinking is that the system we're developing is most likely going to be used in disaster relief, kind of where we need to make food, but it's food to survive, " he said.
“I think as we start to show that this technology is useful over the next couple of years we can start to think about how to scale that to be another tool in dealing with plastic.”
Meantime, in Scotland, scientists are setting their sights on the sweet tooth, converting plastic into vanilla flavouring.
Dr Stephen Wallace, from the Biotechnology department of the University of Edinburgh, says the idea came about when the team was struck by the similarities of a key molecule in the vanilla compound with certain plastic wastes.
“The major component of PET (polyethylene terephthalate, commonly used to make plastic drink bottles) waste is a molecule called terephthalic acid and we were just struck with how similar this molecule was to the compound vanilla, " Dr Wallace said.
“We're not limited to simply turning plastic into vanilla. We can turn it into other flavouring compounds or cosmetics. We can turn it into pharmaceuticals, into sustainable materials. This really is only the beginning."
Is it safe to eat plastic?
But just because we can turn plastic into food, should we?
Dr Wallace says there are still a number of hurdles to jump before it can become a reality.
“For us to be sure that this is safe for human consumption, we have to go through a whole variety of food safety checks, which will take five to 10 years in itself, " he said.
“Theoretically, there is no difference between the molecules that are coming from this bacteria and the vanilla that we eat in our food is derived from oil, from petrochemicals.”
Still, for some people, it might take a bit of convincing that a meal made of plastic is the best solution.
Professor Sahajwalla from SMaRT UNSW says safety needs to be paramount.
”I would really say that when we start to think about what is fit for purpose and how we actually evaluate what we want is best for human beings, we have to, obviously in everything, keep in mind first and foremost, safety and health of people, " she said.
Realistically, we may see plastic officially entering our food chain in the next decade. But, there still needs to be rigorous safety checks before humans can start making protein shakes made from plastic water bottles.
But let’s face it, there’s still an ick factor to eating someone’s used takeaway container.
