Functional characterisation of genetic elements regulating bunch morphology in grapevine

Mannoproteins (MPs) are proteoglycans from the outmost layer of yeast cell walls released into wine during alcoholic fermentation and ageing on lees processes. The use of commercial preparations of mannoproteins as additives to improve wine stability with regards to the crystallization of tartaric salts and to prevent protein haze in the case of white and rosé wines is authorized by the OIV.
Regarding red wines and polyphenols, mannoproteins are described as able to improve their colloidal stability and modulate the astringent effect of condensed tannins. The latter interact with salivary proteins forming insoluble aggregates that cause a loss of lubrication in the mouth and promote a drying and puckering sensation. However, neither the interaction mechanisms involved in mannoproteins capacity to impact astringency nor the structure-function relationships related to this property are fully understood.

Much research has sought to define the complex contribution of terroir (varieties x site x cultural practices) on wine composition. This investigation applied recent advances in chemometrics to determine relative contributions of vine growth, berry maturity and site mesoclimate to wine composition and sensory profiles of Shiraz and Cabernet Sauvignon for two vintages.

Aims: Most consumer research about terroir has focused on wine, particularly with French or other European wine drinkers, rather than those in the Anglo-Saxon world. In Europe, whilst there is no agreement amongst consumers as to what terroir actually is, there is a general recognition of the word and an acceptance that it represents something important

Cognac is a famous spirit produced in southwest France in the region of the eponymous town from wines mainly from Vitis vinifera cv. Ugni blanc. This variety gives very acidic and poorly aromatic base wines for distillation which are produced according to a very specific procedure. Grapes are picked at low sugar concentrations ranging 13-21 °Brix and musts with high turbidity (>500 NTU) are fermented without sulphite addition [1]. Fermentative aromas, as esters and higher alcohols, are currently the main quality markers considered in Cognac spirits.

The primary objective of this research was to investigate the potential benefits of a Fabaceae-based product rich in triacontanol (a long-chain alcohol) applied to Vitis vinifera cv. Merlot, on key physiological and productive parameters of grapevines under controlled water stress conditions.