Evoluzione dei composti polifenolici in vini bianchi della sardegna durante la conservazione in bottiglia e caratterizzazione aromatica

Sardinia has a secular tradition in the wine industry and produces high value wines from red and white grapes. In the last two decades social wineries but mostly private producers have strongly been involved in increasing the quality of wines, in order to become competitive on the national and international markets. Thus, the aim of this work was to characterize bottled Muscat of Sorso- Sennori and Malvasia di Bosa wines for polyphenols, colour and aroma compounds and evaluate their evolution during bottle storage. The phenolic compouds are considered the main compounds responsible of browning of white wine during bottle storage (Cheynier et al.,1989), and these compounds underwent a significant decrease. Flavour GC-MS analysis allowed us to identify 59 aromatic compounds in both wines. In both wines we observed a loss of the characteristic aroma of aromatic grapes. We observed also the reduction of neral and geranial compounds (rose aroma). In Malvasia wine, in contrast to Muscat wine, the increase did not occur for diethyl succinate and ethyl lactate, but there is a total decrease of the same compounds present at bottling (loss of floral and fruity notes). It was also noted the formation of β-citronellol (lemon flavor), the increase in linalool (floral aroma) and α-terpineol (Liliaceae aroma of peach). All the data reported are in agreement with previous findings on Muscat wines and Malvasia grapes (Rossis et al., 2005), but these are the first results on Sardinian Muscat and Malvasia wines.