Characterization of bunch compactness and identification of associated genes in a diverse collection of cultivars of Vitis vinifera L.

AIM: Proteins in white wine can cause cloudiness or haze after bottling, which consumers may consider an indicator of poor quality. . As a consequence, winemakers often use bentonite, a clay-based material that binds protein, to remove proteins and achieve protein stabilisation. However, removing bentonite from wine after treatment can result in a 3-10% loss of wine (1)…

Pectins or pectic polysaccharides are one of the major components in grape skin cell wall, they contribute to physiological processes which determine the integrity and rigidity of grape skin tissue

The search for underground shelters is one of the oldest forms of human habitation, providing refuge in extreme environments such as deserts and polar regions.

Polyphenols are secondary metabolite widely distributed in plant kingdom such as in fruits, in grapes and in wine. During the winemaking process, polyphenols are extract from the skin and seed of the berries. Fining is an important winemaking step just before bottling which has an impact on wine stabilization and clarification. Most the time, fining agent are animal or vegetal protein while some of them can be synthetic polymer like PVPP or natural origin like bentonite.

Despite the extensive research performed during the last decades, the multifactorial mechanism responsible for the white wine protein haze formation is not fully characterized. Herein, a new model is proposed, which is based on the experimental identification of sulfur dioxide as a major modulating factor inducing wine protein haze upon heating. As opposed to other reducing agents, such as 2-mercaptoethanol, dithiothreitol and tris(2-carboxyethyl)phosphine hydrochloride (TCEP), the addition of SO2 to must/wine upon heating cleaves intraprotein disulfide bonds, hinders thiol-disulfide exchange during protein interactions and can lead to the formation of novel inter/intraprotein disulfide bonds. Those are eventually responsible for wine protein aggregation which follows a nucleation-growth kinetic model as shown by dynamic light scattering [1].