Every typical Puerto Rican dish contains an essential ingredient: plantain. Historically, according to the Puerto Rico Agricultural Statistics and Production Index, this tropical fruit has remained among the most consumed foods in the archipelago.
Given this reality, however, the question arises of what to do with the peels and their proper disposal, due to the limited capacity of landfills and the scarce options for recycling or composting.
During her master's thesis, Chemistry professor Yérika Febus proposed a solution, with the goal of reducing the production and use of plastic bags, as well as single-use plastics such as cutlery, plates, and straws.
How? Initially, she created a mixture composed of three plantain peels, water, starch, glycerol, and an acidic component, which generates a biodegradable plastic that leaves no toxic residues.
“Many people think that, because they are plantain peels, they decompose easily and are not a problem. But 35% of organic waste goes to landfills and takes up space, and that takes a long time to decompose. Conventional plastics take thousands of years to decompose. That's where the idea came from to collect something we know is a staple for Puerto Ricans. Many restaurants here produce mofongo and tostones, but where does the waste go? Many of these residues are placed in plastic bags that end up in landfills,” explained Febus, who mentored the research two years ago.
Currently, the Legislature is considering Senate Bill 900, which would eliminate restrictions on single-use plastics in Puerto Rico. Various voices have warned that the measure represents a setback in public policy on solid waste management, as lifting restrictions does not solve the problem of waste accumulation, but rather leaves it unregulated.
In this scenario, Febus affirmed, promoting alternatives such as biodegradable plastics could help mitigate the environmental impact of landfills and plastics in the country.
Research Progress
This semester, the project took a turn when the research team, composed of six undergraduate students from the University of the Sacred Heart, decided to include the ingredient that would complete the ideal mixture to optimize the product's durability and flexibility: beeswax.
“Our plastic is original from Puerto Rico. It is made here and researched by Puerto Rican women. The use of plantain as a main component in our plastic differentiates us from other plastics,” said one of the student members, Yadielis González Muñiz, who is in her fourth year of a bachelor's degree in Biomedical Sciences.
To create the bioplastic, first, three plantain peels are cut into small pieces and boiled until soft; then, a mixture of polysaccharides with glycerol is prepared and heated. The boiled peels are blended until a paste is formed, which is incorporated into the hot mixture, integrating all the components.
Afterward, the beeswax is added, mixing quickly at room temperature until it completely dissolves. Finally, the mixture is poured into a mold and allowed to dry until it solidifies.
Thanks to the use of beeswax as an additive, the bioplastic showed improvement in its elasticity, cohesion, and stability, with greater water resistance. From tests in which samples were submerged weekly in distilled and potable water, a loss of weight was observed over time.
During a seven-week study, the bioplastic lost up to 75% of its initial mass. Based on the results, the amount of added wax was adjusted to evaluate its effect on biodegradation, confirming a significant influence: samples with 0.5 grams of wax lost about 60% of their weight between weeks four and five, while those with 2 grams showed a smaller reduction, around 40%.
“What we are looking for is that the consumer can buy a bag (made of bioplastic) and, when they decide to dispose of it, they can place it in accessible conditions for it to biodegrade,” Febus explained.
Long-term Outlook
As part of a multidisciplinary advance in the research, and in collaboration with Aurorisa Mateo, academic leader of Design and Visual Culture at Sagrado, the development of the first prototype of biodegradable plastic bags is planned for this summer.
“We presented a sample of the bioplastic to her, and it was evaluated that it probably resists stitching. Sometimes, we think science is just science, but it's also art,” Febus explained.
In addition to producing eco-friendly products, the team hopes to educate the public about the importance of reducing plastic use.
“This research has been an opportunity to educate. Because this knowledge goes far beyond the classroom setting. It is something practical that can cause innovation or a change to increase support for the ecosystem,” said Camila Colón Amaro, a student member in her bachelor's degree in Biomedical Sciences.
The other team members –Ariana Rodríguez Durán, Caliaris Colón Martínez, Génesis Gómez Vázquez, and Jaimarie Nazario Reyes– highlighted, for their part, that the project has made them aware of their plastic use.