Interview with Miguel de La Guardia, Professor of analytical chemistry at the University of Valencia
January 16, 2009
The work carried out by scientists from the UV has demonstrated that the analysis of traceability of the wines by optical emission spectroscopy with plasma acoblado inductively and further mathematical treatment, through the use of systems of classification of sets of samples based on their similarities and differencesallows their differentiation.
38 Elements were used to study the classification of samples traces related to the content thereof in the land, the vineyards, the climatology of the area of production and the types of casks and wine production systems.
What does this study to the wine sector, and how much is the benefit?
Our study is to provide the service, producers and consumers a tool objective to discriminate the wines of different denominations of origin, regardless of their geographical proximity. In this sense the three agents mentioned would benefit, though, in my opinion honest wineries, which scrupulously respect the conditions of the appellation, and the regulatory boards will be those who benefit most.
Develop a method to confirm the authenticity of the wine does it mean that cheating regulatory boards and wineries had been detected so far?
There has always been sensitivities about any over-production of designations of high prestige, but it was only possible to detect them if they intercepted a racking of wine between areas. Now there is a methodology that allows to make a portrait robot of the wines produced in a region more than differences of vintages and producers, and I think that we are at the beginning of other studies to detect changes in the processes of an objectively.Without belittling the tasting that evaluates the quality of a wine, but filling in the information with markers chemical in origin and authenticity.
Have been in touch with you from the sector to know and deepen in the study?
So far the survey has been in scientific circles and thanks to you and other publications is happening to public opinion, but still has not been in contact with us no bodega…, and is curious because despite his remarkable reputation in the scientific literature, we have not found data contents of elements trace in French wines of Burgundy or Bordeaux, nor Spanish but known as Rioja or Ribera del Duero designations.
What requirements must carry out a study like the one presented so that it is published by a journal as prestigious as 'Food Chemistry'?
Scientific journals have a methodology of revision of the original based on two criteria. First, the opinion of the editor on the adequacy of the study to the objectives and content of the magazine, and second, the so-called process of censorship ('peer review') which is the review by at least two specialists to whose criteria is submitted work to assess its originalityrigor and alignment between data and conclusions. In the case of 'food chemistry', the process is very rigorous, it is maintaining the prestige of the publication and select what is published between a large number of jobs that are sent for publication.
What has it meant the introduction of techniques as analysis by optical emission further mathematical treatment with coupled plasma spectrometry?
The ICP-OES technique allows fast quantitative analysis of more than 30 elements to levels of concentration in ppm (mg / kg), which enables many details about the samples that was necessary to obtain element by element.
The study has focused especially on Valencia and Murcia wine. Is the formula valid for wines from all over the world?
Focus on Valencian wines is due to our commitment to service to the Valencian society, as we are a public University in here and the employment of many of the samples of Fontanars dels Alforins is due to the generosity of the collaboration of Daniel Belda and Vicente mountain. As for the other wines studied it was to assess the possibilities of discriminate next D.O.. Obviously these studies could be extended to other Spanish and foreign appellations of origin wines.
Currently they are trying to extend this method to vegetables such as rice, artichokes or the famous Alboraya chufas. How are they still advances in this field?
We are in the midst of the campaign of measurement of the composition of elements trace of rice and we are already collecting samples of artichoke. As for the Tiger nuts we will have to wait for the new campaign to ensure the traceability of the samples of local production and we are trying to get samples of the Maghreb and Ethiopia to be able to compare them.
