Yuya Sakai, an associate professor of Industrial Science at Tokyo University and his student Kota Machida say they have successfully made cement using tea leaves, orange and onion peels, coffee grounds, Chinese cabbage, and even lunchbox leftovers. The food cement can be reused and is biodegradable, so it can be buried when it is no longer needed.

Food waste is a huge problem in Japan and worldwide. Japan produced around 5.7 million tons of edible food waste in 2019 and the government aims to reduce that around 2.7 million tons by 2030.

According to Machida, their "ultimate hope is that this cement replaces plastic and cement products, which have worse environmental impacts."