Utilize este identificador para referenciar este registo: http://hdl.handle.net/10400.5/6803
Título: Efeito da enzima Beta-liase Endozym Thiol (R) na libertação de tióis voláteis em vinhos de castas portuguesas
Autor: Chaves, Alex Musialowski
Orientador: Silva, Jorge Manuel Ricardo
Palavras-chave: portuguese grape varieties
Data de Defesa: 2014
Editora: ISA
Citação: Chaves, A.M. - Efeito da enzima Beta-liase Endozym Thiol (R) na libertação de tióis voláteis em vinhos de castas portuguesas. Lisboa: ISA, 2014, 49 p.
Resumo: The French variety Sauvignon Blanc, used for the vinification of white wines, has a very appreciated varietal aroma by worldwide consumers. This aroma comes from its volatile sulfur compounds, denominated volatile thiols or mercaptans. It gives a tropical flavors as boxwood, grapefruit and passion fruit. The volatile thiols responsible for such flavorings are principally: 4-mercapto-4-methylpentan-2-one (4MMP), 3-mercaptohexanol (3MH), ethyl 3-mercaptohexilo (A3MH) and 4-mercapto-4-methyl-pentan-1-ol (4MMPOH), respectively (Darriet and Tominaga, 1995). These compounds are released during the fermentation by the action of yeast which produce the β-lyase enzyme that reacts with the substrate not odorants present in grape, namely: S-cysteine conjugates, the conjugates of S-glutathione and E-hexen 2-al (Murat et al. 2001; Subileal et al. 2008). These compounds are the precursors of thiols. This experiment search the release of the varietal thiols in white portuguese varieties Viosinho, Arinto, Alvarinho and Encruzado and also in red varieties Touriga Nacional and Syrah (the latter, French) by using the enzyme β-lyase Endozym Thiol® produced by the AEB Group, with specific secondary activities, which promote the hydrolysis of grape aromatic tiols precursors as 4MMP, A3MH, 3MH and 4MMPOH. For the determination of the concentrations of thiols in wines studied Analysis was performed with Gas Chromatography coupled to Mass Spectrometry (CG-MS) using the method described by Mateo-Vivaracho et al. (2008). To analyze the effectiveness of the release of tiols aromas in wines that received the enzyme formulation Endozym Thiol® compared with vinified without enzyme added, there was a panel of tests , with 8 trained panelists . As a conclusion, there was a trend in the increase of the global concentrations of thiols in wines that received Endozym Thiol® in winemaking, however, in its thiolated character the aroma tones of tropical fruits and vegetables was not pronounced in wines that received the enzyme.
Descrição: Mestrado em Viticultura e Enologia - Instituto Superior de Agronomia / Faculdade de Ciências. Universidade do Porto
URI: http://hdl.handle.net/10400.5/6803
Aparece nas colecções:BISA - Dissertações de Mestrado / Master Thesis

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