Boscalia Technologies S.L., in collaboration with the Government of Extremadura (Department of Economy, Science, and Digital Agenda) and the European Regional Development Fund (ERDF), is developing the TANNIRS project.
What relationship can there be between wine, wood, and spectroscopy?
Polyphenols are molecules that are abundant in fruit and wood and are involved in various stages of wine aging. The wood of the barrels is an important source of these polyphenols. During the time that the wine is in the barrel, these compounds are released from the wood into the wine, modulating its organoleptic properties (color, aroma, and flavor). An alternative to traditional wooden barrels is the use of steel or aluminum tanks combined with oak alternatives (e.g. chips). This reduces aging times and costs associated with wooden barrels (maintenance, loss due to evaporation, etc.), as well as improves control over the levels of polyphenols that are released into the wine since excessive amounts can be counterproductive.
In recent years, the production of oak alternatives has become more sophisticated, but only French and American oak is commercially available. In Spain, we have several species of oak with the same potential. Their use would allow us to revalue the national product and make forest management and care profitable, boosting the economy in rural areas, creating jobs, and guaranteeing the sustainability of forests and their environmental value. On the other hand, their use would introduce new nuances and properties in the wine sector.
To take this step, it is necessary to provide quality guarantees. This is where Vis-NIR spectroscopy can help in the chemical characterization of woods, ensuring suitable oenological properties for wine aging. So far, the most commonly used techniques are expensive, slow, and destructive. In contrast, spectroscopy is a cheap, non-destructive, and fast technique.
The objective of the project is to provide the wine sector with a fast and effective method based on Vis-NIR spectroscopy to guarantee the quality of forest-origin raw materials (oak alternatives and other potential species) and ensure or improve the organoleptic quality of wines. This opens up the possibility of revaluing woods present in the forests of Spain and specifically in Extremadura, as well as their byproducts without commercial use, improving their profitability and the proper management of forest spaces.
Gas Chromatography Mass Spectrometry (GC-MS).
This technique provides information on molecular weight and structure. It is widely used to determine the content of ellagitannins in wine, but it is expensive, slow, and destructive. Prior to measurements in GC-MS, extractions of wood compounds must be prepared. For this purpose, wood chips are immersed in a hydroalcoholic solution for 15 days. With this technique, we aim to obtain data on the content of eugenol, β-methyloctalactona, guaiacol, 4-methyl guaiacol, vanillin, furfural, and 5-methylfurfural.
Visible-Near Infrared (Vis-NIR) spectroscopy allows for the registration of the “fingerprint” (physicochemical) of wood. The measurements will be performed using our own equipment.
FTIR-ATR spectroscopy, like Vis-NIR, allows for the registration of the “fingerprint” (physicochemical) of wood, but at a different wavelength, so they complement each other. These measurements will be carried out in collaboration with the EcoPast group at the University of Santiago de Compostela.
Once the spectroscopy data (Vis-NIR and FTIR-ATR) and GC-MS data are obtained, they will be statistically analyzed, obtaining different predictive models with different Machine Learning methods. The model that best predicts the content of the different ellagitannins will be chosen.