Análise multiparamétrica da qualidade dos frutos, mostos e vinhos de jabuticaba

• Autor(a) principal: FORTES, Gilmara Aparecida Corrêa
• Data de Publicação: 2012
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da UFG
• dARK ID: ark:/38995/001300000c7hh
• Texto Completo: http://repositorio.bc.ufg.br/tede/handle/tde/1051
• topic: Myrciaria cauliflora; jabuticaba; fermentação; vinho; análise multivariada; Myrciaria cauliflora; jabuticaba; fermentation; wine; multivariate analysis; CNPQ::CIENCIAS EXATAS E DA TERRA::QUIMICA

Chemical parameters were monitored during the jabuticaba s development, fermentation and ageing of its wine, by quantitative 1H NMR, spectrophotometric assays and standard methods of analysis. Data collected were analysed by variance (ANOVA), principal components (PCA), hierarchical cluster (HCA) and canonical correlation analyses (CCA). Jabuticaba s development was analysed in order to identify the optimal harvest period for winemaking. Total acidity decreased 70.5%, whereas reducing sugars increased about threefold in pulps up until the full ripe stage. Anthocyanin levels underwent a sharp increase in the skins reaching 22.0 mg/g at complete maturation. Tannins and total phenols showed no significant differences in their levels between ripe and full ripe stages. The PCA and HCA distinguished two sample groups, the first comprised of samples from the first four days of fermentation characterized by high levels of fructose, glucose, anthocianins and colour intensity (19.90 g/kg; 36.95 g/kg; 177.88 mg/L and 8.6). The second cluster consisted of samples from days 5 to 14 with higher levels of ethanol, glycerol, methanol, acetic acid (75.02; 3.13; 0.19 and 0.99 g/kg), hue and pH (1.25 and 3.49). The canonical correlation analysis confirmed the influence of alcohols (ethanol, methanol and glycerol), organic acids (citric, succinic and acetic acids), pH and titratable acidity on the extraction and stability of anthocyanins and copigments. Three clusters were identified by the multivariate statistical analysis of red wine samples from 2001 to 2010. Cluster I, wines from 2001, 2002, 2003 and 2006, was characterized by chemical age 1 and 3, hue (1.02; 0.89; 1.83), acetaldehyde and alcohols (0.04 and 0.24 g/L). The wines from 2005, 2007 and 2008 formed the second cluster and presented the lowest content of superior alcohols (0.14 g/L). The third cluster was comprised by wines from 2009 and 2010, which contained higher levels of methanol, acetic and latic acids (0.12; 1.24; 0.35 g/L), and the highest pH (3.96). The canonical correlation analysis revealed that chemical age 1, 2 and 3 correlate negatively with anthocyanins, pH and titratable acidity, confirming the importance of pH and acidity in the anthocyanins stability and polimerization.