Mexican Engineer Turning Prickly Pear Juice into Biodegradable Plastic

GUADALAJARA, Mexico – On a recent morning, Sandra Pascoe Ortiz, a chemical engineering professor, sat down at a restaurant and ordered one of her favorite drinks: a blend of grapefruit, pineapple, celery, parsley, spinach and prickly pear cactus.

Pascoe Ortiz for years has been drinking this blend known in Mexico as jugo verde (“green juice”), but she said she also enjoys consuming the prickly pear – a national symbol and staple in the country’s diet – in the many forms in which its pads are popular: grilled, boiled or even raw with salads.

“Ay, que rico,” Pascoe Ortiz said, sipping her green juice. “It’s good.”

Pascoe Ortiz and her students at the University of the Valley of Atemajac just outside Guadalajara have come up with a new use for the prickly pear cactus – known in Mexico as nopal – using its juice as a base for biodegradable plastic.

Sandra Pascoe Ortiz, an engineering professor at the University of the Valley of Atemajac (left), and Alejandra Reyes Diaz, a communications coordinator, disassemble the juicer Pascoe Ortiz uses to extract juice from prickly pear cactus. (Photo by Jorge Valencia/KJZZ)

In 2013, she recalled, some of her students came to her with a class project to use the prickly pear cactus as the base for a biodegradable plastic. They abandoned it after a semester, but Pascoe Ortiz said she told herself, “This can be done.” She continued the project on her own and with other students.

In her lab on campus, Pascoe Ortiz lays out round and square plastic samples she and her students have made since that first classroom experiment. The first samples are rusty brown and roughly the size and shape of U.S. quarters. The most recent samples are light green, paper thin and tough enough to be used as bags, Pascoe Ortiz said.

Samples of plastic made with prickly pear cactus juice by professor Sandra Pascoe Ortiz and her students at the University of the Valley of Atemajac. Pascoe Ortiz and her students began working on the formula in 2013. (Photo by Jorge Valencia/KJZZ)

She initially used Opuntia ficus indica, the variety of prickly pear most commonly used as food. Now she uses Opuntia megacantha, a variety not commonly eaten but instead cultivated for its fruit. She and her students extract the juice, which is bright green, thick and slimey, and mix it with glycerine, animal fat and wax.

A former student, Michelle Mendoza, who recently completed coursework in industrial engineering, is still working with Pascoe Ortiz. Mendoza said she used the formula to make toys for her 3-year-old daughter.

“My daughter loves to buy toys in the markets, and then once she played with it one day, she didn’t want it anymore,” Mendoza said.

Mendoza made the cactus mix and put it into strawberry-shaped molds, she said. Her daughter watched her make them and was excited to play with them at first, but then discarded them just as she’s done with her other toys.

“The same way,” Mendoza said with a laugh. “I need to fabricate more toys.”

At least the prickly pear-based toys will dissolve if she leaves them in water for three weeks, Mendoza said.

Using biodegradable products is good, but using fewer products would be better, said Stephanie Buechler, a University of Arizona professor who studies gender, environment and agriculture. We should focus on reusing the materials we have, she said.

“Using fewer materials will save land. It will save water. It will save the environment by not contaminating as much,” Buechler said. “And then, for the materials we really do need, we should think of ways like this to use less harmful inputs.”

Back at the University of the Valley of Atemajac, Pascoe Ortiz says she would like to see her biodegradable plastic used commercially, though said she plans to continue her work as a researcher and doesn’t expect to see a profit herself.

Pascoe Ortiz hopes the cactus-based plastic will help reduce the impact of solid waste in Mexico and around the world, she said.

“Maybe,” she said, “I’m too much of an idealist.”

This story was first published as a part of the Fronteras Desk, a unique KJZZ project that covers a wide expanse of an under-covered news desert that stretches from northern Arizona deep into northwestern Mexico.

Move over, single-use plastics: Arizona company makes Earth-friendly replacements

GILBERT – From meat trays to mac-and-cheese cups, single-use plastics pack the grocery-store aisles and usually end up in landfills. Now, an Arizona company is on a mission to replace them with biodegradable and compostable products over the next five years.

“We had the vision that the whole world was going to demand alternatives to plastic,” said Troy Swope, founder and CEO of Footprint.

The trick is inventing a material that’s as convenient and useful as plastic.

Mushroom container prototypes made of molded biodegradable fibers are stacked and prepared for shipment to Walmart at Footprint’s facility in Gilbert. (Photo by Celisse Jones/Cronkite News)

Swope, who’s passionate about overcoming obstacles through innovation, and his business partners created Footprint in 2012. The company’s leaders used to work for Intel before putting their technology and innovation skills to work to start their own company.

They now produce packaging for big companies, including Walmart, Costco, Tyson Foods and Kraft.

The company does have competitors, such as Be Green Packaging in South Carolina, but most of these companies are focused on simple solutions to single-use plastics, such as takeout containers. Footprint is working on technology to tackle more difficult plastics, like frozen-food containers and meat trays.

They do this in their manufacturing facility in Gilbert, which recently relocated to a new industrial park. Much of the manufacturing space is empty, but the company, which currently employees 650 people, plans to expand over the next several years, and add 250 workers.

Stacked up along the walls of the production floor are bales of corrugated paper – cardboard – the first step in creating biodegradable products. The paper is ground up and mixed with various solutions, depending on the product, before going through heating machines that mold the material at 338 degrees.

Corrugated fiberboard is stacked before being used to form biodegradable molded-fiber packaging at Footprint. (Photo by Celisse Jones/Cronkite News)

The products are made from a slurry. Different coatings are added to the mixture to create barriers against moisture, oxygen and oil, which is needed for food products to maintain shelf life while in storage.

This year, Footprint began producing paper straws, and it plans to increase straw production by the end of the year. They’re working to find the perfect paper and adhesive combination to make a long-lasting straw.

“The most difficult part is the customers want biodegradability and compostability, yet they still want the product to behave like plastic,” said Yoke Chung, chief technology officer of Footprint.

The science behind the products is important, and so is the company’s environmental impact. It says carbon dioxide emissions are reduced by 40 to 60 percent depending on the type of plastic the Footprint materials are replacing. The company also says energy use drops as much as 50 percent.

“If you start looking at plastic’s true cost,” Swope said, “like the cost to haul it away and store it for 100 and some years, then we’re way lower cost than plastic.”

Mick Dalrymple, director of university sustainability initiatives at Arizona State University, recently toured Footprint. The company has a big, but not impossible, goal, he said.

“It’s a matter of how fast can they scale up. How can they fend off any competitors, and then also things like how can they avoid manufacturers that want to make exclusives with them,” Dalrymple said.

In five years, Footprint has invented more than 400 items, patenting at least three dozen of those items, including containers for produce.

“We want you to walk into a grocery store today, and you see all the plastic, and in five years, you’re going to walk into that grocery store and go, we changed this whole store – the bakery, the meat trays, the yogurt containers, right, the coffee lid on the way out – we’re going to transform that grocery store and it’s going to happen fast,” Swope said.

Footprint plans to increase production in the United States and expand into Mexico and Europe over the next few years.

– Video by Bryce Newberry/Cronkite News