Observatoire Grenache en Vallée du Rhône: incidence du terroir sur certains précurseurs d’arômes et substances volatiles

The Matrix Assisted Laser Desorption/Ionization–Time-Of-Flight Mass Spectrometry (MALDI-TOF MS) technology is commonly used in food and medical sector to identify yeast or bacteria species isolated from a nutritive culture media. Since a decade, brewery and oenology industries have been attracted to this method which combines fast analysis times, reliability and low cost of analysis. Briefly, this method is based on the comparison of the MALDI-TOF/MS protein spectra of an isolated colony of yeast or bacteria with those contain in a manufacturer’s reference protein spectra database. Initiated in 2015, the creation of the first oenological mass spectra database has proved to be essential for increase quality of species identification.

Wine contains secondary metabolites derived from aromatic amino acids (AADC), which can determine quality, stability and bioactivity. Several yeast species, as well as some lactic acid bacteria (LAB), can contribute in the production of these aromatic compounds. Winemaking should be studied as a series of microbial interactions, that work as an interconnected network, and can determine the metabolic and analytical profiles of wine. The aim of this work was to select microorganisms (yeast and LAB) based on their potential to produce AADC compounds, such as tyrosol and hydroxytyrosol, and design a microbial consortium that could increase the production of these AADC compounds in wines.

The aroma of wine grapes is influenced by a complex metabolic network, with terroir factors, especially high temperatures, playing a critical role during berry development.

The Ribera del Duero Designation of Origin (DO) has acquired great recognition during the last decades, being considered one of the highest quality wine producing regions in the world. This DO has grown from 6,460 ha of vineyards officially registered in 1985 to approximately 21,500 ha in 2013. The total grape production stands at around 90 million kg, with an average yield that approaches nearly 4,500 kg/ha. Most vineyards are cultivated under rainfed conditions.

Hydrogels are soil-conditioning materials capable of absorbing substantial amounts of water relative to their weight.