How to Turn Food Waste into Bioplastic

Chairs, synthetic rugs and plastic bags could one day be made out of cocoa, rice and vegetable waste rather than petroleum, according to scientists.

The process they developed and their results, which could help the world deal with its agricultural and plastic waste problems, appear in the ACS journal Macromolecules.

Athanassia Athanassiou, Ilker S. Bayer and colleagues at the Italian Institute of Technology point out that plastic’s popularity is growing. In 2012, its production reached 288 million tons worldwide — but at a cost. Synthetic plastics persist for hundreds or thousands of years while releasing toxic components with the potential to harm the environment and human health. Also, plastics are made out of petroleum, which is a nonrenewable source.

The shift to more environmentally friendly bioplastics has been challenging and expensive. Athanassiou’s team wanted to find a simple, less costly way to make the transition.

They turned to an organic acid that also occurs naturally and can process cellulose, which is the main building component of plants and also the most abundant polymer in nature. They mixed the acid with parsley and spinach stems, and husks from rice (pictured, in the small vial) and cocoa pods. Then, they poured the resulting solutions into lab dishes. When tested, the films that formed showed a promising range of traits from brittle and rigid to soft and stretchable — similar to commercial plastics.

Earlier this year, Sierra Resins begun work to develop biodegradable plastic from fisheries waste streams that can be applied to products that are used in the food services and food processing industry.

Photo Credit: A. Abrusci – Istituto Italiano di Tecnologia