TCA – A status report on South African cork closures

AIM AND METHODS: Grape withering is one of the key steps in the production of the most renowned red wines of the Valpolicella area, namely Amarone and Recioto. This practice, which was already used since Roman times, entails important modifications in grape composition and in the chemical and sensorial characteristics of the corresponding wines, especially in terms of aromatic profile. The aim of this research is evaluating the aromatic evolution during grape withering of the three main varieties used in Valpolicella wines: Corvina, Corvinone and Rondinella.Samples of the three varieties were analyzed at harvest and at different stages of withering, namely10%, 20% and 30% of weight loss. Free and glycosidically bound compounds were extracted and analyzed using Gas Chromatography- Mass Spectrometry (GC-MS). RESULTS: For all the samples the data were normalized to eliminate the effect of concentration due to grape dehydration. Terpene content and evolution varied considerably in relationship to grape variety. Corvinone was richer in cyclic terpenes (including phellandrene, limonene, and cymene) and they decreased during withering.

Resveratrol is a well-known wine constituent with a wide range of activities. In wines, resveratrol can be oxidized to form various derivatives including oligomers [1]. In this study, resveratrol derivative transformation in hydroalcoholic solution was investigated by oxidative coupling using metals. De novo resveratrol derivatives were synthetized and analysed by NMR and MS experiments

S’il n’existe pas de réglementation officielle, la démarche des vins naturels prône un retour aux pratiques dites ancestrales préconisant notamment un mode d’élaboration des vins utilisant le moins d’intrants possible. Le seul autorisé reste l’anhydride sulfureux (SO2) à des doses quatre à cinq fois moins importantes que pour les vins dits conventionnels. Ce désir de renouer avec

The oenological potential of grapes at harvest depends on a combination of the major components of Terroir: the climate, the soil, the plant material, the training system and the crop management.

Pour obtenir des vins d’une certaine gamme, il faut connaître les paramètres liés à la composition de la baie et introduire non seulement les paramètres classiques, c’est-à-dire sucres et acidité, mais aussi les paramètres qui tiennent compte