Postharvest elicitors and metabolic changes in wine grape berries

Preliminary experiment of harvest timing was carried out in Eger wine district, Hungary in 2009. In situ physiological responses, berry quality parameters and wine quality of the Kékfrankos grapevine were studied at two growing sites (Eger-K6lyuktet6 – non-stressed, flat vineyard, and Eger-Nagyeged hill – water stressed, steep slope vineyard).

In this work, results about the composition in polyphenols and polyamines in important wine-grape cultivars from the Emilia-Romagna region are presented. Spectrophotometric and HPLC analyses suggest that especially coloured berries are particularly rich of antioxidant species (stilbenes and catechins). Potential allergenic capability of biogenic amines was also characterized.

Accumulation of anthocyanins (Anth) on whole winegrape (Vitis vinifera L.) bunches attached to the vine was monitored by a fluorescence-based sensor (Multiplex) on ‘Aleatico’ and ‘Nero d’Avola’. Different water regimes were applied.

The aim of this study was to determine how artificial shading influenced berry development and anthocyanin accumulation in ‘Cabernet sauvignon’. Opaque polypropylene boxes were applied to grape bunches over three different developmental stages.

This study showed that Botrytis cinerea could degrade the phenolic compounds by its enzymatic activity. It led to a diminution of skin’s anthocyanins from 20 % to 50 % and an increase level up to 40 % of individual proanthocyanins, 30 % of the %G and 25% of the %P.