Turning cellulose into starch for new food source
1 May 2013 by Evoluted New Media
A potential food source can be created from plants not traditionally thought of as food crops suggests a team at Virginia Tech who have succeeded in transforming cellulose into starch.
This discovery could help feed our growing global population which is estimated to reach nine billion by 2050.
“Cellulose and starch have the same chemical formula,” explained team leader Y.H. Percival Zhang, an associate professor of biological systems engineering in the College of Agriculture and Life Sciences and the College of Engineering.
“The difference is in their chemical linkages. Our idea is to use an enzyme cascade to break up the bonds in cellulose, enabling their reconfiguration as starch.”
Cellulose, the supporting material in plant cell walls, is the most common carbohydrate on earth. The researchers suggest that food could be made from any plant, reducing the need for crops to be grown on valuable land.
The starch that Zhang’s team produced is amylose, a linear resistant starch that is not broken down in digestion and is a good source of fibre.
The approach takes cellulose from non-food plant material, such as corn stover – the stem, leaves and husk of the corn plant which remains after the ears of corn are harvested. The process converts about 30% to amylose and hydrolyses the remainder to glucose suitable for ethanol production.
The method called ‘simultaneous enzymatic biotransformation and microbial fermentation’ involves cascading enzymes to transform one carbohydrate into another. It is easy to scale up for commercial production and is environmentally friendly because it doesn’t require expensive equipment, high temperatures or chemical reagent and is waste-free.
The discovery also holds promise in applications beyond food systems.
“Besides serving as a food source, the starch can be used in the manufacture of edible clear films for biodegradable food packaging. It can even serve as a high-density hydrogen storage carrier that could solve problems related to hydrogen storage and distribution,” said Zhang.
The research was published the Proceedings of the National Academy of Sciences.
