RESUMO
The major areas of the world where viticulture is practiced enjoy temperate or cool temperature climates. When wine grapes are grown in tropical regions, edaphoclimatic factors result in distinct grape quality attributes, and production techniques also require significant adjustment. The objective of this study was to characterize the chemical compositions, in particular of phenolic compounds, of Syrah grapes grown in two location in northeast Brazil - these are also at widely different altitudes. A range of methods of phenolic extraction were used, along with classical chemical analyses including for organic acids, sugars, monomeric anthocyanins, flavonols, stilbene, condensed tannins and some of the monomeric and small oligomeric procyanidins. The regions and their diverse environments had a larger influence than harvest year. The grapes at higher altitude (Bahia, 1.100â¯m asl (metres above sea level) were characterized by higher levels of malic acid, anthocyanins and condensed tannins in the skins. The low-altitude grapes (Pernambuco, 350â¯m asl (metres above sea level) had higher levels of glucose, fructose, 3-O-acetylglucoside anthocyanins and condensed tannins in the seeds. Fruit composition was highly influenced by the region. In the low-altitude region, the grapes were characterized by higher tartaric and citric acid in the must, also of flavonols in skins and of tannins in the seeds. Meanwhile, the fruit from the high altitude, contained higher levels of malic and succinic acid in the must, and of anthocyanins and condensed tannins in the skins.
Assuntos
Altitude , Clima Tropical , Vitis/química , Antocianinas/análise , Antioxidantes/análise , Benzaldeídos/análise , Biflavonoides/análise , Brasil , Catequina/análise , Cromatografia Líquida de Alta Pressão , Cor , Fazendas , Flavonóis/análise , Frutose/análise , Frutas/química , Glucose/análise , Peso Molecular , Fenóis/análise , Análise de Componente Principal , Proantocianidinas/análise , Sementes/química , Estilbenos/análise , Taninos/análise , Vinho/análiseRESUMO
BACKGROUND: Obtaining two or more successive annual vintages from the same vineyard is characteristic of regions with a tropical climate, such as the Submédio of the São Francisco Valley, Brazil. The present study aimed to characterize the chemical composition of grapes in four production cycles (i.e. two calendar years) when considering the interaction between cv. Syrah and two rootstocks. For a broad characterization, two methodologies for the extraction of phenolic compounds were used, as well as different methods of analysis. RESULTS: The results obtained showed that there was an influence of rootstock and harvest season. Grapes from vines grafted onto IAC 313 contained higher concentrations of total condensed tannins (skins) and flavanols than grapes from vines grafted onto 1103P. However, the grape samples from the vines grafted onto 1103P contained higher levels of monomeric anthocyanins than the grape samples from the vines grafted onto IAC 313. The first harvest season was characterized by higher concentrations of most phenolic compounds than the second harvest season. CONCLUSION: In the present study, it was possible to confirm that, in the semiarid region of Brazil, the interaction between the cultivar Syrah and the different rootstocks, as well as the climatic conditions in each harvest season, influenced the composition of the grapes, mainly in relation to phenolic compounds. © 2019 Society of Chemical Industry.