New electronic tongue quantifies antioxidants in juice

A new electronic tongue system that can be applied to the analysis of the antioxidant power and other quality parameters of juices, fruit and fruit purées, has been developed by a team of Spanish researchers.

Researchers from the Centre for Molecular Recognition and Technological Development (IDM) and the CUINA group of the Universitat Politècnica de València, Spain, developed the technology and computer software as a fast way to test the antioxidant power of fruits and juices.

So far, the experts have tested the system in different antioxidant solutions –specifically, citric acid, ascorbic acid (vitamin C) and malic acid – with the researchers noting that the results have been ‘highly satisfactory’.

Technology

The researchers explained that the system is based on techniques of voltammetry and impedance spectroscopy.

“What we do is, we apply electrical signals to the solution and we measure its response. Thus we can quantify the antioxidant concentration in that solution,” said Miguel Alcañiz, an IDM researcher.

Now, researchers say they are working on investigating the degradation of vitamin C in juices.

“We're starting to work very soon in the direct application of the electronic tongue to the evaluation of orange juice,” said José Manuel Barat, a researcher in the CUINA group.

Electronic tongues

According to the UPV researchers, in recent years, electronic tongues have become an excellent alternative to traditional methods of analysis for controlling the quality of food products.

“Electronic tongues, using electrochemical techniques, help us to sort food samples in situ and to quantify their physicochemical parameters, in a fast and economical way,” said Ramón Martínez Máñez, a researcher at the UPV IDM.

The Spanish team have also used similar electronic tongue principles and technologies to investigate the detection of glyphosate (a weed killer which is widely used in agriculture) and to monitor water quality in sewage treatment plants.