Influence of protein stabilization with aspergillopepsin I on wine aroma composition

The effect that some extraction techniques, such as ultrasound (Cacciola, Batllò, Ferraretto, Vincenzi, & Celotti, 2013; Povey & McClements, 1988) or microwaves (Carew, Close, & Dambergs, 2015; Carew, Gill, Close, & Dambergs, 2014) produce on the aroma of red wines, when applied to processes of extractive nature, such as pre-fermentative maceration or ageing with oak chips (Spanish oak – Quercus pyrenaica and French oak – Quercus robur) has been studied. The volatile profile was determined by means of gas chromatography coupled with olfactometric and mass spectrometric detection. A sensory analysis was also carried out. No indications were found to show that the pre-fermentative treatment with microwaves or ultrasound modified the sensory profile of the wines whereas the application of such energies during the ageing phase showed some positive trends at sensory level.

The composition of wine is largely determined by the composition of pre-fermentation juice, which is influenced by extraction of grape components. Different grape harvesting and processing conditions could affect the extraction of grape components into juice. Among these grape components, pathogenesis-related (PR) proteins are of great concern for white wine maker as they are the main cause of haze formation in finished white wine. If not removed before bottling, these PR proteins may progress into haze through the formation of complex with phenolics under certain conditions. Thaumatin-like proteins (TLPs) and chitinases are the main constituents of PR proteins found in protein haze.

Cultivation of a few number of clones is causing the loss of vineyard biodiversity, resulting in the disappearance of biotypes that could be of interest to face future challenges,

L’extraction phénolique au cours de la fermentation à partir de vendanges de différents degrees de maturité du cépage Syrah/R99 a été etudiée. Cette travail fait parti d’un projet focalisé sur la qualité du raisin et des vins obtenus au cours du millésime 2002. Les vignes sont situées à Stellenbosch (Afrique du Sud) sur un sol Glenrose

A set of Syrah plots covering a wide range of terroirs distributed in the vineyards of the Rhone Valley and the Mediterranean South is examined through their oenological and sensory characteristics. The multidimensional analysis of data leads to the following groupings: (1) A group of unstructured wines with a simple aromatic profile dominated by fruity-floral notes; they come from plots where the ripening conditions have been disturbed by unfavorable climatic conditions, or an excess harvest.