Researchers from the Polytechnic University of Valencia (UPV, Spain) and the University of Gavle (Sweden) have created an electronic nose with 32 sensors that can identify the odours given off by chopped pears and apples.
"The fruit samples are placed in a pre-chamber into which an air flow is injected which reaches the tower with the sensors which are metal oxide semiconductors that detect odorous compounds such as methane or butane," Jose Pelegri Sebastia, UPV researcher at the Gandia campus and co-author of the paper, said.
Next, software is used to gather real time data and the information is processed through classification algorithms.
The results can be viewed on a 3D graph which distinguishes between the pear and apple scores.
This study is the starting point for new research the team is already involved in to develop multisensor systems that increase the capacity to differentiate complex mixtures of volatile substances.
"One example would be the wine making sector," Pelegri said, "where an electronic nose capable of distinguishing the quality or type of grape or recognising the vintage a wine belongs to would be very useful."
Other lines of research focus on the field of biomedicine. Some studies have shown that trained dogs can detect cancerous tumours, such as lung cancer, by smelling a person's breath.
The research is published in the 'Sensors and Actuators A' journal.