RESUMO
BACKGROUND: Knowledge of the chemical composition of wine and its association with the grape variety/cultivar is of paramount importance in oenology and a necessary tool for marketing. Phenolic compounds are very important quality parameters of wines because of their impact on colour, taste and health properties. The aim of the present work was to study and describe the non-flavonoid and flavonoid composition of wines from the principal red grape varieties cultivated in Mendoza (Argentina). RESULTS: Sixty phenolic compounds, including phenolic acids/derivatives, stilbenes, anthocyanins, flavanols, flavonols and dihydroflavonols, were identified and quantified using high-performance liquid chromatography with diode array detection coupled with electrospray ionisation mass spectrometry (HPLC-DAD/ESI-MS). Marked quantitative differences could be seen in the phenolic profile among varieties, especially in stilbenes, acylated anthocyanins and other flavonoids. CONCLUSION: The polyphenolic content of Malbec wines was higher compared with the other red varieties. Dihydroflavonols represent a significant finding from the chemotaxonomic point of view, especially for Malbec variety. This is the first report on the individual phenolic composition of red wines from Mendoza (Argentina) and suggests that anthocyanins, flavanols and phenolic acids exert a great influence on cultivar-based differentiation.
Assuntos
Flavonoides/análise , Qualidade dos Alimentos , Frutas/química , Fenóis/análise , Pigmentos Biológicos/análise , Vitis/química , Vinho/análise , Acetilação , Antocianinas/análise , Antocianinas/química , Argentina , Cromatografia Líquida de Alta Pressão , Análise Discriminante , Fermentação , Flavonoides/química , Frutas/crescimento & desenvolvimento , Frutas/metabolismo , Concentração de Íons de Hidrogênio , Estrutura Molecular , Peso Molecular , Fenóis/química , Pigmentos Biológicos/biossíntese , Especificidade da Espécie , Espectrometria de Massas por Ionização por Electrospray , Espectrofotometria Ultravioleta , Estilbenos/análise , Estilbenos/química , Vitis/crescimento & desenvolvimento , Vitis/metabolismo , Vinho/microbiologiaRESUMO
The ability of Lactobacillus hilgardii 5w to metabolize gallic acid and catechin was evaluated. It was grown in a complex medium containing gallic acid or catechin. The metabolites were analyzed by high-performance liquid chromatography and identified by comparing the retention times and spectral data with the standards of a database. In gallic acid-grown cultures, gallic acid, pyrogallol, catechol, protocatechuic acid, p-hydroxybenzoic acid, p-hydroxybenzaldehyde, and p-hydroxybenzyl alcohol were detected. In catechin-grown cultures, catechin, gallic acid, pyrogallol, catechol, p-hydroxybenzoic acid, acetovanillone, and homovanillic acid were detected. This work presents evidence of gallic acid and catechin degradation by L. hilgardii from wine.