The Institute of Industrial Science at The University of Tokyo is researching a new method to reduce food waste by recycling discarded fruit and vegetable scraps into robust construction materials.
“Our goal was to use seaweed and common food scraps to construct materials that were at least as strong as concrete,” said Yuya Sakai, the senior author of a study into the practice.
The researchers borrowed a ‘heat pressing’ concept that is typically used to make construction materials from wood powder, except they used vacuum-dried, pulverised food scraps, such as seaweed, cabbage leaves, and orange, onion, pumpkin, and banana peels as the constituent powders. The processing technique involved mixing the food powder with water and seasonings, and then pressing the mixture into a mould at high temperature. The researchers tested the bending strength of the resulting materials.
“With the exception of the specimen derived from pumpkin, all of the materials exceeded our bending strength target,” said Kota Machida, a senior collaborator. “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 new materials retained their edible nature, and the addition of salt or sugar improved their taste without reducing their strength. Furthermore, the durable products resisted rot, fungi, and insects, and experienced no appreciable changes in appearance after exposure to air for four months..