Mexican Scientist Discovers a Way to Turn Nopal Cactus Into Biodegradable Plastic
By Elias Marat
As the crisis of plastic waste grows, researchers have looked for various ways to cut down on single-use plastics, with many cities and countries across the world seeking to put an end to plastic bags, straws, and other common products in favor of more sustainable, environmentally sound options.
And at the University of the Valley of Atemajac (UNIVA) which lies just outside of Guadalajara in Mexico’s Jalisco state, chemical engineering professor Sandra Pascoe Ortiz has found a novel alternative to plastic—one based on nopal, or prickly pear cactus, which has long been a national symbol of Mexico and a crucial staple of the Mexican diet.
Pascoe and her students have devised a way to form a new biodegradable plastic using the juice from the edible cactus’ fruit, known as the tuna, to make the innovative new product.
Pascoe told the BBC:
It’s a non-toxic product. All the materials we use can be ingested both by humans or animals. And they wouldn’t cause any harm.
This alternative to plastic made from cactus leaves is biodegradable, and fish can eat it too.
— BBC World Service (@bbcworldservice) June 4, 2019
The cactus-based plastic is formed out of the juice of the nopal, which contains sugars, pectin, and organic acids that grant it a viscous consistency.
When the juice is blended with a mixture of glycerol, colorants, proteins, natural waxes and decanted to remove the fiber, the formula is then dried out on a hot plate to produce the plastic.
In a separate interview with EFE news agency last year, Pascoe explained how she collaborated with the University of Guadalajara Center for Biological and Agricultural Sciences to measure just how quickly and in which conditions the new biodegradable plastic would break down. Pascoe noted:
“We’ve done very simple degradation tests in the laboratory; for example, we’ve put it in water and we’ve seen that it does break down [but] we still have to do a chemical test to see if it really did completely disintegrate. We’ve also done tests in moist compost-like soil and the material also breaks down.”
The invention could provide a crucial substitute for the commonly used petroleum-based plastics that are choking waterways and ocean life worldwide. Instead, this biodegradable plastic would either harmlessly dissolve or feed sea creatures rather than contributing to their demise.
For the time being, however, the production of the cactus-based plastic is limited to Pascoe’s lab, where she and her students spend time manufacturing the potentially revolutionary substitute.
Her former students have even experimented with using the formula to produce toys for their kids, according to KJZZ.
Michelle Mendoza, who has completed her industrial engineering but continues working with Pascoe, explained:
My daughter loves to buy toys in the markets and then once she played with it one day, she didn’t want it anymore.
So Mendoza made strawberry-shaped plastics that excited her daughter for a bit, but then met the same fate as the rest of her toys and were discarded after a day in “the same way,” she laughingly said, noting that at least the nopal-based toys can be dissolved in water after three weeks unlike plastic toys.
Professor Sandra Pascoe Ortiz remains hopeful that one day, her biodegradable plastic can be used commercially, although she doesn’t have plans to turn a huge profit and become some sort of bio-plastic tycoon.
Instead, she hopes to simply continue her work as a researcher and reduce the impact of solid waste in Mexico and around the world.
Maybe I’m too much of an idealist.