Rejoice beer lovers!
Chemists at the Complutense University of Madrid have developed a method that allows brewers to measure the freshness of beer, using a polymer sensor that changes colour upon detecting furfural, a compound that appears when this beverage ages and gives it a stale flavour. The sensor can be controlled from a smartphone app also created by the team.
The researcher pointed out that till now brewers have measured furfural and other freshness indicators using methods based on chromatography techniques. “But these methods involve the use of expensive equipment and sample preparation is very time-consuming,” added Elena Benito-Pena from the university.
These sensors, made from a polymer similar to the one used to manufacture contact lenses, have been designed to change colour (from yellow to pink) when they come into contact with a beer containing furfural. “We have incorporated an aniline derivative into the sensor material which reacts with the furfural and produces a pink cyanine derivative that allows us to identify the presence of the marker in the sample. The intensity of the colour increases as the concentration of furfural in the beer rises and, thus, as more time passes since the beer was produced,” researchers said.
The team has also created a mobile app for Android smartphones that, by taking a picture of the sensor disc, allows for the identification of the amount of furfural present in the beer. With this data, the degree of freshness can be determined. In the future it will also be available for Apple IOS.
The study is published in the journal Analytical Chemistry.