Trans-resveratrol concentrations in wines Cabernet Sauvignon from Chile

Sulphur dioxide (SO2) seems indispensable in winemaking because of its properties. However, a current increasing concern about its allergies effects in food product has addressed the international research efforts on its replacement. This supposes a sufficient knowledge of its properties and conditions of use. Several studies compared SO2 properties against new alternatives that are supposed to overcome SO2 disadvantages. Firstly, the state of art on SO2 wine replacements is revised, and secondly, the last promising results using natural enriched polyphenol extracts are shown.

Sorting Chenin blanc is one of the most important white wine cultivars in South Africa. It has received a lot of attention and accolades in the past years and more research than ever is dedicated to this versatile cultivar. According to the Chenin blanc association of South Africa, there are three recognized dry wine styles, Fresh and Fruity (FF), Rich and Ripe Unwooded
(RRU), and Rich and Ripe Wooded (RRW). They are traditionally established with the aid of expert sensory evaluation, but the cost and the (subjective) human factor are aspects to be taken into account. A more objective and possibly robust way of assessing and attributing these styles can be the use of chemical analysis.

In the winemaking process, several compounds that remain in the grape skins and seeds after the fermentation stage are bioactive-compounds (substances with potential beneficial effects on health) that can be extracted in order to recovery valuable substances with a high commercial value for the cosmetic, food (nutraceuticals) and pharmaceutical industries. The skins contain significant amounts of bioactive substances such as tannins (16-27%) and other polyphenolic compounds (2-6.5%) in particular, catechins, anthocyanins, proanthocyanins, quercetin , ellagic acid and resveratrol.

For characterization, sensory designing and authentication rapid analytical technologies have become available. Some, like Proton Transfer Reaction Mass Spectrometry allow a rapid spectrum of the volatile compounds of wines. Combined with chemometrics wines can be characterized. The same approach can be used to calculate the results of virtual mixtures and allow formulation of constant quality blends. Other new techniques and portable devices based on spectroscopy allow measurements on production sites and in grocery stores, even for the smart consumer. We will present some examples of the application of these techniques for authentication of wines, both in the laboratory and on site.

Beihong and Beimei are two wine cultivars from ‘Muscat Hamberg’ (V. vinifera L.) and wild V. amurensis Rupr., which were released in China in 2008. Here，two enology practices were reported. Firstly, the impact of different yeasts including D254, GRE, K1, D21 and BDX on dry wine quality of Beihong and Beimei was investigated. For Beihong, among wines fermented by all yeasts, residual sugar content was the lowest, total anthocyanin and resveratrol contents were the highest in the wine by D254. However, the wine by D254 had lower titrable acid than those by the other yeasts except BDX.