UPCYCLING: POTATO PEELS, STARCH & BIO-PLASTICS
John Mmbaga
Academic | Founder at Circular Dynamics Ltd. | Circular Economy Consultant
Photo credit: Polina Tankilevitch via Pexels
Potato chips colour our parties.
They are the go-to meal when we just want that fast filling, sumptuous and easy to fix snack.
A few of us like to cook potatoes with the skin.
But for those of us who peel them, where do we dispose of these wastes?
Well, there are a few places where peels could find use.
Composting them helps return their nutrients back to the soil…
Incorporating them into animal feeds helps enrich livestock diets.
These are viable options of making use of potato waste.
But do they generate high value?
STARCH
Potato peels are composed of starch, the carbohydrate that makes most of the potatoes we eat.
And the peel starch content is highest when removed before cooking.
This is because when we peel, we also remove some thin slices of the starch-containing potato.
Now potato peels may still be washed thoroughly, stir fried and eaten as a delicacy.
However starch could be extracted when these same peels are cut up into smaller pieces and mixed thoroughly with water.
When that happens, starch can be identified as the whitish, foamy stuff that floats on water.
When this step is repeated over several times, a substantial amount of starch could be extracted after water is evaporated.
This starch powder is very useful in several cooking applications.
But it is also potentially crucial in packaging.
Let me explain.
BIO-PLASTICS
The starch could be mixed with water to form a paste.
A bit of vinegar could be added for preservation, while glycerin is added under heat to hold the plastic together.
Once this paste is jelly-like it could be spread on a flat surface to form thin films which dry after a day or two.
These thin bio-plastic films could them be peeled off and used to make bio-plastic paper or wrapping foils.?
Bio-plastics could be used to wrap everyday commodities, which we carry in ordinary plastic bags.
But that’s not where the magic ends.
When these bio-plastics reach their end-of-life, they could be disposed off anywhere since microorganisms can degrade them by feeding on the starch.
Alternatively, they could be thrown into a water body where the starch breaks up and dissolves as glucose.
Bio-plastics could helps solve one of the worst environmental catastrophes of our age.
PLASTIC POLLUTION
A lot has been said about plastics.
But among the many concerns, microplastics are not emphasized enough.
You see, synthetic plastics like the ones used to make drinking water bottles don’t degrade.
They may remain intact for over 500 years!
However, their physical structure is over time messed up by the power of the elements.
It will not take long for a discarded plastic bottle to break up into microplastics.
Now, microplastics are so small in size, they can penetrate even into our blood stream.
Some microplastics have even been isolated from breast milk and the human placenta, meaning that even unborn infants are not spared.
Worse still, the effects of long-term exposure to them are still a mystery.
So in a world where synthetic plastics thrive, the risk of exposure to microplastics is more real than we can think.
However, bio-plastics carry with them a very strong advantage over the synthetics.
BIODEGRADABLE
Just like the starch film we were talking about, bio-plastics are made up of naturally occurring substances such as cellulose, starch and chitin – to name but a few.
When such packaging is thrown away, it is broken down fast by bacteria or even eaten by animals – we could also eat such packaging safely!
IN CONCLUSION
Synthetic plastics not only ruin our environment but expose us to risks of microplastics.
So why not toy and tinker around with food waste to produce biodegradable plastics?
As the global population soars, the demand for energy giving foods like root and tuber plants will be on the rise.
So, as farmers capitalize on the possible gains, sustainability enthusiasts could take advantage of the wastes generated to make high value products such as bio-plastics.
That’s what upcycling is all about.
Originally posted on cleannovate blog