Publicação
Is Saccharomyces cerevisiae the only yeast capable of producing wine?: exploitation of Torulaspora delbrueckii for winemaking
| Resumo: | Wine is a unique and complex beverage resulting from the combination of several factors, with yeasts playing a fundamental role in its development. Non-Saccharomyces yeasts were considered, for many years, a source of contamination during production and conservation of wines, which labelled them as spoilage microorganisms. However, more recently, the use of these unconventional microorganisms for wine fermentation has been widely investigated and discussed, due to their impact on the complexity of the organoleptic profile of the final product. Among this group, Torulaspora delbrueckii has been gaining prominence in the winemaking sector owing to its contribution with low volatile acidity, the release of sweet compounds, colour intensity and sensory perception of wines. In this work, a set of T. delbrueckii strains with different geographical and technological origins were used to evaluate the phenotypic behaviour of this species through a battery of tests with biotechnological relevance from an oenological point of view. Then, the fermentative character of the isolates with greater phenotypic heterogeneity was evaluated, through individual fermentations in synthetic medium simulating the grape must. Furthermore, strains’ metabolic profile was assessed by high-performance liquid chromatography (HPLC) on glucose (found to be a strain-dependent feature), ethanol content, volatile acidity, glycerol and organic acids concentrations. These analyses showed that temperatures above 37 ºC and 14 and 18 % (v/v) ethanol concentrations, significantly affected T. delbrueckii’s growth. On the other hand, the majority of the strains shared a great resistance to stress environments, including in the presence of fungicides. HPLC analysis reflected variable results with ethanol production, glycerol and citric acid concentrations contributing the most for inter-strain variability. However, a higher production of acetic acid (0.44 to 3.17 g/L) was observed, going against literature reports that describe a lower production of T. delbrueckii in comparison with S. cerevisiae. Our results disclosed three T. delbrueckii strains, isolated from natural environments, and that combine a great fermentative power, the release of high contents of glycerol, and a high resistance and production of ethanol, highlighting their oenological potential. |
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| Autores principais: | Fernandes, Ticiana Barbosa |
| Assunto: | non-Saccharomyces yeasts Torulaspora delbrueckii Wine Saccharomyces cerevisiae Organoleptic profile Leveduras não-Saccharomyces Vinho Perfil organoleptico |
| Ano: | 2021 |
| País: | Portugal |
| Tipo de documento: | dissertação de mestrado |
| Tipo de acesso: | acesso aberto |
| Instituição associada: | Universidade do Minho |
| Idioma: | inglês |
| Origem: | RepositóriUM - Universidade do Minho |
| Resumo: | Wine is a unique and complex beverage resulting from the combination of several factors, with yeasts playing a fundamental role in its development. Non-Saccharomyces yeasts were considered, for many years, a source of contamination during production and conservation of wines, which labelled them as spoilage microorganisms. However, more recently, the use of these unconventional microorganisms for wine fermentation has been widely investigated and discussed, due to their impact on the complexity of the organoleptic profile of the final product. Among this group, Torulaspora delbrueckii has been gaining prominence in the winemaking sector owing to its contribution with low volatile acidity, the release of sweet compounds, colour intensity and sensory perception of wines. In this work, a set of T. delbrueckii strains with different geographical and technological origins were used to evaluate the phenotypic behaviour of this species through a battery of tests with biotechnological relevance from an oenological point of view. Then, the fermentative character of the isolates with greater phenotypic heterogeneity was evaluated, through individual fermentations in synthetic medium simulating the grape must. Furthermore, strains’ metabolic profile was assessed by high-performance liquid chromatography (HPLC) on glucose (found to be a strain-dependent feature), ethanol content, volatile acidity, glycerol and organic acids concentrations. These analyses showed that temperatures above 37 ºC and 14 and 18 % (v/v) ethanol concentrations, significantly affected T. delbrueckii’s growth. On the other hand, the majority of the strains shared a great resistance to stress environments, including in the presence of fungicides. HPLC analysis reflected variable results with ethanol production, glycerol and citric acid concentrations contributing the most for inter-strain variability. However, a higher production of acetic acid (0.44 to 3.17 g/L) was observed, going against literature reports that describe a lower production of T. delbrueckii in comparison with S. cerevisiae. Our results disclosed three T. delbrueckii strains, isolated from natural environments, and that combine a great fermentative power, the release of high contents of glycerol, and a high resistance and production of ethanol, highlighting their oenological potential. |
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