Japan turns discarded noodles into biodegradable paper

Researchers at the University of Kagawa have developed a method for converting discarded udon noodles into biodegradable paper.

According to Science Japan (SciJ), the new material is produced using microorganisms that transform food waste into thin cellulose sheets resembling traditional Japanese washi paper.

The project is led by Professor Naotaka Tanaka of the Faculty of Agriculture. The idea was developed as a way to reduce food waste in Kagawa Prefecture, a region known across Japan for its sanuki udon noodles.

The process begins by grinding leftover noodles and mixing them with water. Enzymes are then added to break down starch into glucose. Next, acetic acid bacteria are introduced, forming a cellulose film over several days. The resulting membrane is air-dried and turned into paper sheets without conventional papermaking methods.

Researchers say that one portion of udon can produce between five and ten A4-sized sheets. The material is reportedly more resistant to moisture and tearing than regular paper, while remaining fully biodegradable in soil.

Professor Tanaka began experimenting with microbial paper about 16 years ago, initially as an educational project studying bacterial cellulose synthesis. He later adapted it to address food waste and support local communities.

The production is now run in cooperation with a charitable organisation, creating jobs for people with disabilities. Current output is about 100 sheets per month.

The material is already being used for promotional products and artistic works, with researchers also exploring potential applications such as biodegradable fishing bait and other eco-friendly products.