Joined: 16 Mar 2004
|Posted: Mon Aug 24, 2009 3:36 pm Post subject: How to Tell your Pinot from your Plonk
|Authenticating wine - a taste of things to come
Vintage Margaux Lafitte - only £1,218.78 a bottle
There is no eyeballing, swirling, sniffing or swishing, no waxing lyrical over beautiful summery aromas of red berries, but a high-energy ion beam and an electronic tongue can sort the pinot from the plonk and authenticate the vintage of a rare tipple.
In the first of these sauvignon savvy technologies French scientists and wine merchants have teamed up to develop a tool using particle accelerators to authenticate vintage wines and to spot a fake.
Arcane, the technological transfer unit at the Centre d'études nucléaires in Bordeaux Gradignan, has signed an exclusive cooperation agreement with The Antique Wine Company which specializes in the international vintage wine trade, to authenticate the glass in the bottles by ion beam analysis.
Just like works of art, wine is now being subjected to advanced testing to establish its authenticity: after measuring caesium 137 radioactivity levels to test the age of the wine, the glass in vintage wine bottles is now being tested by particle acceleration.
Authentication of the glass in a wine bottle by ion beam
The London-based company, which specializes in the international fine wine trade, has asked Arcane to find a way of assessing the age of some of the 10,000 bottles that the company buys or sells annually on behalf of its clients. It wants to offer its customer base a new authentication service for vintage wine.
Arcane analyses the X-rays emitted when bottles are placed under an ion beam produced by the particle accelerator at the AIFIRA platform. This enables researchers to verify the age and provenance of the bottles and thus to authenticate the vintage, rather like checking a painter's signature on a masterpiece, without opening the bottle or damaging the contents in any way.
The results obtained for the glass are then compared with the certified database set up by Arcane using data from the analysis of the glass from 80 bottles of red Bordeaux wine ranging from the 19th century to today, for the most part fine wines from St Émilion and the Médoc region.
Authentication is possible because of both the complexity of the glass manufacturing process, which have evolved over time, and the diversity of glass-making production centers, which give each object a characteristic signature. Analysis by ion beam provides information about the age of the wine by dating its container, thereby overcoming some of the limitations of the caesium 137 radioactivity technique, which cannot be used to date wine produced before 1950.
The Electronic Tongue
Meanwhile, an electronic tongue that can 'taste' the grape varieties and vintages of wine has been created by Spanish scientists.
Cecilia Jiménez-Jorquera from the Barcelona Institute of Microelectronics, and colleagues, created a multisensor device and trained it to distinguish between different wines and grape juices.
When speaking with specialists of the wine industry, the need for a rapid route to obtain valuable information about product quality was noticed, explains Jiménez-Jorquera. It takes a long time to send samples to a centralised laboratory for analysis with complex equipment.
Jiménez-Jorquera's electronic tongue combines an array of six ion-sensitive field effect transistor-based chemical sensors, with cross-sensitivity to multiple ions in solution. The data is then analysed with an appropriate chemometric method. 'This system enables the rapid and simultaneous measurement of different analytical parameters related to the quality control of wines and grape juices,' says Jiménez-Jorquera.
The electronic tongue is small and robust, Jiménez-Jorquera explains, and it is portable - which is essential for field measurements. She adds that the device could be used to detect frauds committed regarding the vintage year of the wine, or the grape varieties used.
The advantage of this device is that it is 'fast, easy and relatively cheap' says Sue Ebeler from the University of California, Davis, US, who has studied wine flavour chemistry. 'One of the most interesting aspects,' Ebeler adds, 'is the ability to predict sugar, acid and alcohol content using sensors that are not specifically sensitive to these components but respond to cations and heavy metals.'
The next step, says Jiménez-Jorquera, will be to extend the number of samples analysed to get more precise results, and give the best training for this electronic tongue. Other kinds of chemical sensors can then be incorporated to broaden the field of applications to other beverages and foods.