Food waste can be recycled into construction materials

A team of scientists at the University of Tokyo has discovered how to turn food waste into robust construction materials that retain their edible nature. Pulverized banana peels, cabbage leaves, and seaweed were used to create materials that have the strength of concrete.

Study senior author Yuya Sakai is a sustainable construction materials specialist and a professor in the Institute of Industrial Science at The University of Tokyo.

“Our goal was to use seaweed and common food scraps to construct materials that were at least as strong as concrete,” said Professor Sakai. “But since we were using edible food waste, we were also interested in determining whether the recycling process impacted the flavor of the original materials.”   

The experts tested out a heat-pressing technique that is used to compress wood powder into construction materials. In place of wood, the team pulverized a variety of vacuum-dried food waste items, including onion and banana peels.

According to the researchers, the processing technique involved mixing the food powder with water and seasonings, then pressing the mixture into a mold at high temperature.

“With the exception of the specimen derived from pumpkin, all of the materials exceeded our bending strength target,” said study co-author Kota Machida. “We also found that Chinese cabbage leaves, which produced a material over three times stronger than concrete, could be mixed with the weaker pumpkin-based material to provide effective reinforcement.”

The World Food Program estimates that one-third of the world’s food is wasted every year, valued at $1 trillion. With this in mind, the researchers said it is crucial for develop methods for recycling food waste. 

The experts noted that since the new materials are strong enough for construction projects yet still edible, there could be a number of creative applications to come from this research.

The study is published by The Society of Materials Science of Japan. 

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By Chrissy Sexton, Earth.com Staff Writer