Sandra Pascoe, a researcher from the University of the Valley of Atemajac (Univa) used the most common variety of edible nopal cactus (the opuntia ficus-indica and the opuntia megacantha) to make a biodegradable and bio-based plastics (bioplastics).
Nopal is a common name in Mexican Spanish for Opuntia cacti. The English word is prickly pear.
“The plastic is basically made out of the sugars of nopal juice, the monosaccharides and polysaccharides it contains. The sugars, pectin and organic acids in the juice give it a very viscous consistency. Thanks to the viscosity, a solid material can be produced.”
Glycerol, natural waxes, proteins and colorants are mixed with the juice after it has been decanted to remove its fiber. The formula is then dried on a hot plate to produce thin sheets of plastic.
The process was registered with the Mexican Institute of Industrial Property (IMPI) in 2014 and the National Council of Science and Technology (Conacyt) has contributed funding to advance the project.
Pascoe is collaborating with the University of Guadalajara Center for Biological and Agricultural Sciences to determine how quickly and under what conditions the plastic will decompose.
“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,” Pascoe said.
The Cactus bioplastics could be used to make shopping bags, cosmetic containers, jewelry and toys. They’re currently testing how much weight the plastic can bear to determine what other uses it the bioplastics will have. Next steps towards commercialization: buying a machine that can make prototypes of the plastic bags .
Pascoe is applying for a patent at IMPI. She would be open to let other companies use the process under a licensing agreement.
A picture of Pascoe at work in her lab.