In a study published this spring in US science journal PNAS, Chinese scientist Percival Zhang has outlined a process he and his colleagues conceived to transform solid cellulose – derived from wood, grass or corn husks – into a carbohydrate called amylose. To achieve this, a cocktail of enzymes (derived from bacteria, soil fungi and potatoes) was used to break down the cellulose into small entities and reassemble them into edible starch. The resultant material takes the form of a sweet powder.
In the short term, this engineered, low-calorie starch could be used as a coating similar to bread crumbs. US medical research and education website Mayo Clinic says that, like fat, cellulose can also help to keep food moist, making it a popular substitute for oil or butter in low-fat baked goods. Other cellulose products are already used as additives in certain processed foods (like salad dressings and ice cream) to improve consistency and volume. Unlike many other cellulose variations, however, Zhang’s formula contains no glucose, making it viable for sugar-free cooking.
However, high production costs present an obstacle in bringing this product to market. US publication Science Magazine reports that Zhang estimates it would cost around $1m to turn 200 kg of crude cellulose into 20 kg of starch, which is only enough to feed one person's carbohydrate needs for 80 days. However, the scientist believes that within a decade, the same thing could be achieved for 50 cents per person per day.
"We will have a potential of approximately 4.5 billion tons of starch, which is nearly twofold the annual production of cereal – that is 2.3 billion tons per year now," said Zhang. This could provide up to 30% of the food that prior studies estimate is needed to feed the world in 2050.
For more on how natural materials are being used in surprising and inventive ways to create important new products and applications, see Fungi in the Biological Age.