The new electronic smelling system – from the Agro-Food Quality Improvement Group at the Universitat Jaume (UJI), Castelló de la Plana – is expected to help food firms discriminate which tomatoes, melons or other products have the most attractive aroma.
Existing devices typically deliver variable results depending on changing laboratory conditions. Salvador Roselló, UJI researcher, explained: “The environment, laboratory temperature, humidity, and so on, exert a significant influence, which means that to ensure the evaluations are useful an extensive amount of correction work has to have been carried out through a methodology that can be transferred to other teams and products.”
The result is a new method that enables the aromatic characteristics of different samples of a product to be compared efficiently allowing the best quality items to be selected. It could also support food manufacturers’ quality control systems, said the researchers.
Based on a study by Mercedes Valcárcel, the method corrects the fluctuations in the aroma analyses on specific days and between days.
The smelling device is an electronic instrument equipped with chemical sensors and a chemometric programme for pattern recognition which recognises and compares individual or complex odours. Like the human olfactory system, the instrument compares new aromas with those stored in its electronic memory in order to rank various smells.
Conventional aromatic assessments are time-consuming and expensive relying either on tasting panels or chemical analysis using a gas-mass spectrometer. But the new method allows more assessments to be conducted much more cheaply, said Roselló.
“In the case of tomatoes, there are more than 40 aromas involved,” he added. “But…the important thing is that as a whole they are perceived to be appropriate.
“Another advantage of using this equipment is that samples can be frozen and evaluated gradually so that in a period of some months, you may have evaluated significant numbers of samples.”
The university is working with several tomato and melon companies to refine the electronic nose.
Valcárcel’s study is entitled Optimization of the process of evaluating and selecting tomato germplasm according to organoleptic quality characteristics: Use of NIR technology and electronic sensors.