Publicação
Valorization of woods from wine ageing and development of methodologies for their reutilization
| Resumo: | Ageing is a key step in the production of several premium products and has been for long used in the modification of sensory characteristics of alcoholic beverages. Scientific research has unraveled the complex phenomena occurring during ageing, focusing mainly on beverage transformations. This thesis however, sets out on understanding the transformations occurring to cooperage wood when used in ageing beverages, and its impact when reused for ageing subsequent matrices. Study of mass transfer showed that the porous structure of oak wood retains wine, along with its chemical composition. Uptake follows a saturation curve, with rate of uptake influenced by particle size and maximum uptake influenced by wood variety. Several wine volatile compounds are retained in wood, namely esters, alcohols and acids, while wood still maintains some content in its characteristic compounds, namely furans, lactones, phenolic compounds and aldehydes. Research on compound extraction showed that wine volatiles are adsorbed by hydrophobic interactions with wood, generating novel extractable composition. These compounds are subsequently extracted to other matrices when reusing cooperage wood, attaining a novel partition equilibrium. Ethanol concentration was shown to affect significantly extraction of compounds adsorbed by wood, whereas temperature showed no significant effect. Extraction of wood compounds is also affected by ethanol concentration as well as temperature for some compounds. Thus, control of extraction conditions can lead to targeted volatile composition. Impact of wood reuse was demonstrated by reapplying oak chips for the incorporation of volatile compounds in beer, wine and spirits, where beer stood out as a more favorable matrix. By using different wood concentrations and extraction temperatures, different volatile compositions were generated, leading to different perceived sensory characteristics. Transference of wine compounds was also shown in traditional barrel ageing of beer, where ageing methods further impacted volatile composition. A prominence of D. bruxellensis was identified, which motivated its isolation for the development of an accelerated process for beer ageing. D. bruxellensis was applied in co-culture with S. cerevisiae as multi-starter for beer ageing, which allowed the accelerated production of metabolites associated with barrel aged beer. Thus, the added value of used cooperage wood was shown along with methodologies for its reutilization and revalorization. |
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| Autores principais: | Coelho, Eduardo João Louro |
| Assunto: | extraction oak wood sensory properties sorption wood ageing propriedades sensoriais adsorção extração madeira de carvalho maturação Ciências Agrárias::Biotecnologia Agrária e Alimentar |
| Ano: | 2020 |
| País: | Portugal |
| Tipo de documento: | tese de doutoramento |
| Tipo de acesso: | acesso aberto |
| Instituição associada: | Universidade do Minho |
| Idioma: | português |
| Origem: | RepositóriUM - Universidade do Minho |
| Resumo: | Ageing is a key step in the production of several premium products and has been for long used in the modification of sensory characteristics of alcoholic beverages. Scientific research has unraveled the complex phenomena occurring during ageing, focusing mainly on beverage transformations. This thesis however, sets out on understanding the transformations occurring to cooperage wood when used in ageing beverages, and its impact when reused for ageing subsequent matrices. Study of mass transfer showed that the porous structure of oak wood retains wine, along with its chemical composition. Uptake follows a saturation curve, with rate of uptake influenced by particle size and maximum uptake influenced by wood variety. Several wine volatile compounds are retained in wood, namely esters, alcohols and acids, while wood still maintains some content in its characteristic compounds, namely furans, lactones, phenolic compounds and aldehydes. Research on compound extraction showed that wine volatiles are adsorbed by hydrophobic interactions with wood, generating novel extractable composition. These compounds are subsequently extracted to other matrices when reusing cooperage wood, attaining a novel partition equilibrium. Ethanol concentration was shown to affect significantly extraction of compounds adsorbed by wood, whereas temperature showed no significant effect. Extraction of wood compounds is also affected by ethanol concentration as well as temperature for some compounds. Thus, control of extraction conditions can lead to targeted volatile composition. Impact of wood reuse was demonstrated by reapplying oak chips for the incorporation of volatile compounds in beer, wine and spirits, where beer stood out as a more favorable matrix. By using different wood concentrations and extraction temperatures, different volatile compositions were generated, leading to different perceived sensory characteristics. Transference of wine compounds was also shown in traditional barrel ageing of beer, where ageing methods further impacted volatile composition. A prominence of D. bruxellensis was identified, which motivated its isolation for the development of an accelerated process for beer ageing. D. bruxellensis was applied in co-culture with S. cerevisiae as multi-starter for beer ageing, which allowed the accelerated production of metabolites associated with barrel aged beer. Thus, the added value of used cooperage wood was shown along with methodologies for its reutilization and revalorization. |
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