Effects of different antioxidant strategies on the phenolic evolution during the course of a white winemaking process

Commercial oenological tannins (TECs) are widely used in the wine industry. TECs are rich in condensed tannins, hydrolyzable tannins or a mixture of both. Wine grapes are a important source of proanthocyanidins or condensed tannins while oak wood possess a high concentration of hydrolyzable tannins (Obreque-Slier et al., 2009). TECs contribute with the antioxidant capacity of wine, catalyze oxide-reduction reactions and participate in the removal of sulfur compounds and metals.

In front of the economic interest and seeking to respect their environment, the wine growers move gradually towards a policy of reasoning their plant health protection. This is why, starting from epidemiologic studies on grapevine pathogens, forecasting models of the risks are developed by research and experimentation bodies.

The use of compost as amendment in agriculture is a well-established practice, strongly recommended for numerous benefits.

The aim of this work was to reduce the alcohol content of Tempranillo wine. Tempranillo wines were produced by grapes harvested at different ripening dates (August 11 which was 21 oBrix and September 28 with 25 oBrix). At the second date, the Tempranillo wines were elaborated as follows: grapes were destemmed, crushed and collected into 50 L stainless-steel vats. Before preferementative maceration in cold, 50 % (M1) and 70 % (M2) of the must have been replaced by the same percentage of must from the first harvest. In addition, a control wine (C) was performed with only grapes from the second harvest.

Today, the concept of precision vine management (or site-specific viticulture) has a great relevance. It is based on the practice of a different management in relation to the different features of the crop site. In this way, all practices should be adapted to the land spatial variability and should be linked to the real needs of vines.