23 May 2013

Tackling the orange waste mountain

Orange Peel

During orange juice production only around a half of every orange is turned into juice. The remainder is considered waste or used for animal feeds. Chemical engineers in Brazil – the world’s largest producer of oranges - are now looking at ways to promote better use of the by-products for human consumption and use.

Around 70 million tons of oranges are grown worldwide each year1. During the production of orange juice it is estimated that up to 20 million tons of waste is produced mainly from the peel, pulp, seeds, orange leaves and fruits that do not meet quality standards. Most orange waste is turned into pellets for animal feed, spread onto soil near production units or simply burned.

At the Federal University of Santa Catarina in Brazil, a study2 by the Department of Chemical and Food Engineering, has reviewed the economic, nutritional and environmental potential of orange waste, which is known to contain soluble sugars, cellulose, pectin and other essential oils that could form the basis for several industrial processes.

The study proposed a range of uses of orange waste including in the manufacture of paper; the absorption of pollutants; as a fertilizer; a potential new fuel source, including bio-fuels and charcoal; and as a food ingredient with antioxidant properties.

The Institution of Chemical Engineers’ (IChemE) chief executive David Brown said: “Reducing food waste and improving food supply is a growing concern across the world as population grows and resources come under increasing pressure.

“It’s an issue where chemical engineers can make a unique contribution including the development of processes and technologies to optimise food supply. Turning orange waste into a raw material for new products is a challenge worth embracing, and a field worthy of further research and investment.”

The work of chemical engineers and their role in reducing food waste and improving food supply is explored in IChemE’s new technical strategy – Chemical Engineering Matters.

IChemE is a registered charity in England & Wales and a charity registered in Scotland (SC 039661).