The concept of terroir: what place for microbiota?

The selection of a suitable grape variety (Vitis vinifera L.) for specific viticulture and oenology objectives is a considerable challenge in the context of climate change.

This work aimed at setting up a multivariate and geostatistical methodology to map natural terroir units of the viticultural areas at the province scale (1:125,000).

A critical aspect of wine quality from a consumer perspective is the overall impression of wine flavour, which is formed by the interplay of volatile aroma compounds, their precursors, and taste and matrix components. Grapes contribute some potent aroma compounds, together with a large pool of non-volatile precursors (e.g. glycoconjugates and amino acid conjugates). Aroma precursors can break down through chemical hydrolysis reactions, or through the action of yeast or enzymes, significantly changing the aroma profile of a wine during winemaking and storage. In addition, glycoconjugates of monoterpenes, norisoprenoids and volatile phenols, together with sulfur-conjugates in wine, provide a reservoir of additional flavour through the in-mouth release of volatiles which may be perceived retro-nasally.

San Joaquin Valley accounts for 40% of wine grape acreage and produces 70% of wine grape in California. Fruit quality is one of most important factors which impact the economical sustainability of farming wine grapes in this region. Due to the recent drought and expected labor cost increase, the wine industry is thrilled to understand how to improve fruit quality while maintaining the yield with less water and labor input. The present study aims to study the interactive effects of mechanical leafing and deficit irrigation on yield and berry compositions of Cabernet Sauvignon grown in warm climate of California.

Tyrosol (TYR) and hydroxytyrosol (HYT) are bioactive phenols present in olive oil and wine, basic elements of the Mediterranean diet. TYR is reported in the literature for its interesting antioxidant, cardioprotective and anti-inflammatory properties. In wine, its concentration can reach values as high as about 40 mg/L
[Pour Nikfardjam et al. 2007] but, more frequently, this phenol – derived from yeast metabolism of tyrosine during fermentation – is present at lower levels, generally higher in red wines compared to whites. HYT was measured for the first time by Di Tommaso et al. [1998] in Italian wines – with maximum values of 4.20 mg/L and 1.92 mg/L for red and white wines, respectively – while definitely lower concentrations have been found later in Greek samples.