Scientists squeeze value from citrus peel
The university is leading a new EU-backed scheme, called the Biowaste Industrial Symbiosis Network, to explore how green chemical technologies could be deployed to turn food waste into useful chemicals.
“We are using green chemical technologies such as low temperature microwave processing and supercritical carbon dioxide extraction (both food-compatible) to extract valuable chemicals such as pectin, limonene, fatty acids, aromatic compounds etc,” Professor James Clark, director of the University of York’s Green Chemistry Centre of Excellence, told FoodProductionDaily.com.
“In some cases we can also do chemistry on these natural chemicals, for example, converting limonene to other terpenes.”
Commercial applications
Waste valorisation research projects currently underway at the Green Chemistry Centre of Excellence include project ‘OPEC’ (orange peel exploitation company), which uses microwaves to break down the cell structure of orange and other citrus peels to release the most valuable chemicals.
The researchers are also using supercritical carbon dioxide and bio-solvents to remove valuable chemicals from the surface of different types of biomass, from cereal straws to citrus peel and sugar cane bagasse, and deriving new adhesives from biomass.
In terms of how the chemicals produced could be used in a commercial context, Prof Clark said: “Uses include solvents, flavours and fragrances, chemical and polymer intermediates, food additives, cosmetics ingredients and bio-fuel intermediates.”
One food waste derived material is already being produced and marketed commercially by university spin-off Starbon Technologies.
The material - branded Starbon – is a patented class of bio-based mesoporous materials derived from polysaccharides. It has several specialist applications, such as for purifying water and cleaning up waste streams by removing harmful organics and heavy metals, and for recovery of precious metals through reductive adsorption.
Industry recruits
The network, which is being coordinated by PhD student Lucie Pfaltzgraff, brings together engineers, chemists, biotechnologists and food technologists from academia and industry.
Unilever and the Greek food company Food Hellas are among the food industry recruits so far, along with the food waste processing companies Veolia and Brockelsby, and Prof Clark said they were “talking to several others about collaboration.”
The network has just received a boost in the form of a European Co-operation in Science and Technology (COST) grant. Prof Clark said the grant was dependent on the number of members but was likely to be around £100,000 for four years.
“The EU support we are receiving is an acknowledgement that food supply chain waste is an important area of scientific study that has potential to change significantly the way we live,” he said.
