Loading...
Publication
Determinação de ácidos orgânicos e compostos fenólicos em vinhos produzidos a partir de castas autóctones da região do algarve por cromatografia líquida de alta eficiência (HPLC) e cromatografia líquida acoplada à espectrometria de massa (LC-MS)
| Name: | Description: | Size: | Format: | |
|---|---|---|---|---|
| 1.69 MB | Adobe PDF |
Authors
Advisor(s)
Abstract(s)
A região vitivinícola do Algarve situa-se no extremo sul de Portugal e é caracterizada pelas condições edafo-climáticas da região. Um dos fatores mais importantes para a identidade dos vinhos algarvios é a diversidade do património vitícola que reside nas castas autóctones, Negra Mole e Crato Branco. A Negra Mole encontra-se na base dos famosos vinhos palhete e clarete dando origem a vinhos leves e frutados. A Crato Branco (ou Síria) é uma casta branca que produz vinhos frutados com aroma cítrico. A qualidade do vinho está diretamente relacionada com a composição química das uvas. A presença de determinados ácidos orgânicos nas uvas, afetam as características organoléticas do vinho. O objetivo desta dissertação foi estudar os ácidos orgânicos e compostos fenólicos presentes nestas castas e em vinhos produzidos a partir destas. Foram realizadas análises físicas-químicas às uvas e otimizados métodos analíticos de cromatografia líquida de alta eficiência (HPLC) modo isocrático para quantificação de ácido cítrico, succínico, chiquímico, cafeico, gálico, vanílico, catequina, resveratrol e antocianinas a diferentes comprimentos de onda. Também foram identificados diferentes compostos fenólicos presentes nas uvas e vinhos por LC-MS. As uvas Negra Mole apresentaram maior teor de ácido tartárico (387,9 ± 0,6 mg/kg matéria seca) e as uvas Crato Branco a maior concentração de ácido málico (141,2 ± 0,2 mg/kg matéria seca). A maior quantidade de resveratrol (3,54 ± 0,01 μg/g matéria seca) e antocianinas foram detetadas nas uvas Negra Mole, nomeadamente, nas películas (0,07 ± 0,01 mg/g matéria seca). Nos vinhos estudados foi determinado que a maior quantidade de ácido tartárico se encontra nos vinhos produzidos com Negra Mole (6,13 ± 0,03 g/l). As maiores concentrações de antocianinas foram detetadas nos vinhos tintos (420,56 ± 0,01 mg/l) e a maior quantidade de resveratrol foi detetada nos vinhos brancos (9,94 ± 0,01 mg/l).
The Algarve wine region is located in the extreme south of Portugal and is characterised by the particular conditions of the region. One of the most important factors in the identity of Algarve wines is the diversity of their viticultural heritage, which is rooted in the autochthonous grape varieties, Negra Mole and Crato Branco. Negra Mole is the basis for the famous Palhete and Clarete wines. Crato Branco (or Síria) is a white grape variety that produces fruity wines with citrus aroma. The quality of the wine is directly related to the chemical composition of the grapes that´s why certain organic acids in grapes affects the characteristics of the wine. The objective of this dissertation was to study the organic acids and phenolic compounds present in these grapes and in the wines produced from them. Physical and chemical analyses were performed on the grapes and part of a high-performance liquid chromatography (HPLC) was optimised for the quantification of citric acid, succinic acid, shikimic acid, catechin, caffeic acid, gallic acid and vanillic acid at different wavelengths. The phenolic compounds in grapes and wines were also identified by LC-MS. Negra Mole grapes had the highest tartaric acid content (387,9 ± 0,6 mg/kg dry weight) and Crato Branco grapes had the highest malic acid content (141,2 ± 0,2 mg/kg dry weight). The highest amounts of resveratrol (3,54 ± 0,01 μg/g dry weight) and anthocyanins were detected in Negra Mole, specifically in the grape skins (0,07 ± 0,01 mg/g dry weight). Among the wines studied, the highest tartaric acid content was found in wines from Negra Mole grapes (6,13 ± 0,03 g/l). The highest concentration of anthocyanins was found in red wines (420,56 ± 0,01 mg/l) and the highest amount of resveratrol was detected in white Wines (9,94 ± 0,01 mg/l).
The Algarve wine region is located in the extreme south of Portugal and is characterised by the particular conditions of the region. One of the most important factors in the identity of Algarve wines is the diversity of their viticultural heritage, which is rooted in the autochthonous grape varieties, Negra Mole and Crato Branco. Negra Mole is the basis for the famous Palhete and Clarete wines. Crato Branco (or Síria) is a white grape variety that produces fruity wines with citrus aroma. The quality of the wine is directly related to the chemical composition of the grapes that´s why certain organic acids in grapes affects the characteristics of the wine. The objective of this dissertation was to study the organic acids and phenolic compounds present in these grapes and in the wines produced from them. Physical and chemical analyses were performed on the grapes and part of a high-performance liquid chromatography (HPLC) was optimised for the quantification of citric acid, succinic acid, shikimic acid, catechin, caffeic acid, gallic acid and vanillic acid at different wavelengths. The phenolic compounds in grapes and wines were also identified by LC-MS. Negra Mole grapes had the highest tartaric acid content (387,9 ± 0,6 mg/kg dry weight) and Crato Branco grapes had the highest malic acid content (141,2 ± 0,2 mg/kg dry weight). The highest amounts of resveratrol (3,54 ± 0,01 μg/g dry weight) and anthocyanins were detected in Negra Mole, specifically in the grape skins (0,07 ± 0,01 mg/g dry weight). Among the wines studied, the highest tartaric acid content was found in wines from Negra Mole grapes (6,13 ± 0,03 g/l). The highest concentration of anthocyanins was found in red wines (420,56 ± 0,01 mg/l) and the highest amount of resveratrol was detected in white Wines (9,94 ± 0,01 mg/l).
Description
Keywords
Ácidos orgânicos Compostos fenólicos HPLC Castas autóctones Vinhos algarvios