UVALINO WINE: CHEMICAL AND SENSORY PROFILE

1. D. Borsa, F. Piano, F. Bonello, L.Chiusano and M.C. Cravero CRA – Centro di Ricerca per l’Enologia – Via P. Micca, 35 – 14100 Asti E mail: daniela.borsa@entecra.it Introduction Uvalino cv. is a Piedmont native variety only recently admitted as licensed Italian grapevine. The wines obtained from this variety showed a purple red colour with some intense orange highlights and a good tannin content that give to wines a high astringency; the olfactory description shows spicy notes. Due to their characteristic wines produced from this variety need two years of ageing. The aim of this work was to assess Uvalino wines produced in different years. The chemical data were compared with the sensory profiles. Materials and methods In the present work two experimental wines from different vintages (2004 and 2006) were evaluated in 2009. Current analyses (alcohol, dry extract, total and volatile acidity, pH, fixed acids) were carried out according to the official methods (G.U. C.E. n. 272 3/10/1990). Polyphenol indexes (Di Stefano et al., 1989), colour intensity and hue were measured too. Free and glycoside aroma compounds of wines were analysed via GC and GC-MS as described in (10). Sensory analysis was realized, by the trained panel of the CRA-ENO (12 tasters). The wine sensory profiles were performed using a non structured sensory sheet, accomplished in a previous work (Cravero and Ubigli,2002). The chemical and the sensory results were submitted to the ANOVA and to the Duncan test (p=95%). Tasting sessions were realized in an ISO tasting room with ISO approved glasses. UVALINO WINE: CHEMICAL AND SENSORY PROFILE Results and discussion The characterisation of varietal and fermentative aromatic compounds showed a high content of benzenoids, particularly benzyl alcohol. Their presence, together with C13-norisoprenoid compounds, gave to the wines important sensory features correlated to the sensory analysis. The evaluation of the wine sensory profile showed that fermentative aromatic compounds play a key role in wine aroma development in non aromatic grapes. Isoamyl acetate, 2-phenylethanol and 2-phenylethyl acetate, responsible for fruity and floral notes of wines, were the more correlated with the sensory descriptors identified. Uvalinowines showed a high alcohol content, a low acidity and a high pH. Moreover they presented a remarkable content of polyphenolic compounds. The concentration of anthocyanins was particularly low, whereas the content of tannins, responsible for the intense astringency, was high. Flavan-3-ols content was consistent during wine aging. In spite of low concentration of anthocyanins, the perceived intensity of colour was high: this proved that the molecules giving colour to wines reached a high degree of stability. This colour stability was also observed in the oldest wine demonstrating that co-pigmentation reactions took place. Some other compounds contributed to the olfactory features of the wines despite their concentration was lower than their identification threshold. This argued synergy and masking phenomena took place and the taster could not distinguish the individual contribution of each compound to the wine odour. The sensory profile of the wines showed that the taste and olfactory persistence was constant during passing the time. The structure and astringency of wines were high during wine aging too. The visual description of wines showed that orange highlights increased as far as the wine was older: this observation was expected as a conseguence of colour evolution. Spicy and aromatic herbaceous notes became more intense in the oldest wines. Conclusions The resultsconfermedthatUvalinowines show a colourstabilityduringagingdespite a low concentration in anthocyanins. Benzenoid,C13-norisoprenoids togetherwith fermentative aromaticcompouds are the mayorresponsibleforwinesolfactoryprofile. The chemical and sensory analysis showed how different molecules present in wines can contribute in a complex way to the formation of the sensory profile of a product. REFERENCE LIST 1] BORSAD., L. CORINO, M.BORIO, L. MONTICELLI e R. DI STEFANO (2003). Acta VII International Symposium of Oenology – Arcachon [2] CRAVERO M.C., TZOLAKIS C., BONELLO F., PISANO G., BORSA D. (2008). Riv. Vitic. Enol. N. 2-3-4/2008 [3] CRAVERO M.C., UBIGLI M. (2002). Industria delle bevande, (XXXI, settembre): 342-349. ISSN 0390-0541 [4] DI STEFANO R., CRAVERO M.C., GENTILINI N. (1989). L’Enotecnico, (XXV, 5): 83-89