A carregar...
Publicação
Biogenic amines in wine: gene transcription as a tool for selection of Oenococcus oeni starter strains
| Nome: | Descrição: | Tamanho: | Formato: | |
|---|---|---|---|---|
| 4.09 MB | Adobe PDF |
Autores
Orientador(es)
Resumo(s)
Wine is a complex environment where the microbial flora can have both a
positive (e.g. malolactic fermentation) and a negative (e.g. production of
biogenic amines) impact on the quality of wine.
Biogenic amines are nitrogenous compounds of low molecular weight that can
be found in fermented food and beverages, including wine. Biogenic amines
are formed primarily by decarboxylation of the corresponding amino acids by
microorganisms through substrate-specific decarboxylases. Some authors
consider the presence of biogenic amines to be a fundamental parameter for
detriment of alcoholic beverages. These compounds can have adverse health
effects on sensitive individuals at high concentrations.
The role of microorganisms in wine involves two important fermentation
processes, the alcoholic fermentation conducted by yeasts and the malolactic
fermentation conducted by lactic acid bacteria. The malolactic fermentation
refers to the conversion of L-malic acid into L-lactic acid and CO2, catalysed
by the malolactic enzyme. This mechanism contributes for deacidification,
bacterial stability and flavour changes in wine. Oenococcus oeni is the leading
lactic acid bacteria responsible for malolactic fermentation, mainly due to its
adaptability to such a chemically harsh wine environmental (low pH and high
ethanol concentrations).
The two main goals of this PhD thesis were to contribute to the: (1) increase of
knowledge of biogenic amines occurrence in wine; (2) oenological
characterization and selection of Portuguese autochthonous O. oeni strains,
isolated from different winemaking regions, to be used as malolactic starters
on the wine industry.(...)
Descrição
Dissertation presented to obtain the Ph.D degree in Biology
Palavras-chave
Contexto Educativo
Citação
Editora
Universidade Nova de Lisboa. Instituto de Tecnologia Química e Biológica