Percorrer por autor "Barbosa, Catarina"
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- Characterizing the potential of the non-conventional yeast Saccharomycodes ludwigii UTAD17 in winemakingPublication . Esteves, Marcos; Barbosa, Catarina; Vasconcelos, Isabel; Tavares, Maria João; Mendes-Faia, Arlete; Mira, Nuno Pereira; Mendes-Ferreira, AnaNon-Saccharomyces yeasts have received increased attention by researchers and winemakers, due to their particular contributions to the characteristics of wine. In this group, Saccharomycodes ludwigii is one of the less studied species. In the present study, a native S. ludwigii strain, UTAD17 isolated from the Douro wine region was characterized for relevant oenological traits. The genome of UTAD17 was recently sequenced. Its potential use in winemaking was further evaluated by conducting grape-juice fermentations, either in single or in mixed-cultures, with Saccharomyces cerevisiae, following two inoculation strategies (simultaneous and sequential). In a pure culture, S. ludwigii UTAD17 was able to ferment all sugars in a reasonable time without impairing the wine quality, producing low levels of acetic acid and ethyl acetate. The overall effects of S. ludwigii UTAD17 in a mixed-culture fermentation were highly dependent on the inoculation strategy which dictated the dominance of each yeast strain. Wines whose fermentation was governed by S. ludwigii UTAD17 presented low levels of secondary aroma compounds and were chemically distinct from those fermented by S. cerevisiae. Based on these results, a future use of this non-Saccharomyces yeast either in monoculture fermentations or as a co-starter culture with S. cerevisiae for the production of wines with greater expression of the grape varietal character and with flavor diversity could be foreseen. View Full-Text
- Enhancing vineyard resilience: evaluating sustainable practices in the Douro demarcated regionPublication . Oliveira, Manuel João; Gonçalves, Igor; Soares, Rui; Pereira, Sofia; Moreira, Helena; Sousa, Ana Sofia Silva; Castro, Paula; Barbosa, CatarinaIn Mediterranean agriculture, sustainability and productivity are seriously threatened by climate change and water scarcity. This situation is exacerbated by poor management practices such as excessive use of agrochemicals, overgrazing, and monoculture. The Douro Demarcated Region (DDR) is an emblematic region, classified as a World Heritage Site by UNESCO in 2001. Viticulture is the main agricultural activity in DDR, widely known to produce Port wine. So far, new approaches have been developed to redesign Mediterranean agroecosystems with greater resilience and productivity, focusing on the development of sustainable agricultural production systems through the combined use of biotechnological tools and environmentally respectful agronomic practices, enhancing soil functions and health by employing bioinoculants, remediation techniques, cultivation systems, and climate-adapted crops in each studied region. The present study aims at assessing the impact of bioinoculants’ application and cover cropping on grapevine growth and water stress management in DDR vineyards. A trial was conducted in a commercial vineyard, where treatments with bioinoculants (plant growth promoting bacteria and/or arbuscular mycorrhizal fungi) and cover cropping (sown with hydrogel), were applied. Exposed leaf area and predawn leaf water potential were measured to assess treatment impacts on grapevines. The results indicate that bioinoculants’ application in cover cropping seeded with hydrogel promote grapevine leaf expansion, increasing vegetative biomass, and enhancing nutrient uptake. Additionally, cover cropping contributed to greater soil water availability, reducing plant water stress during dry periods. These findings underscore the potential of these sustainable practices to improve vine health and increase resilience to adverse climatic conditions in the Douro region.
- H. guilliermondii impacts growth kinetics and metabolic activity of s. cerevisiae: the role of initial nitrogen concentrationPublication . Lage, Patrícia; Barbosa, Catarina; Mateus, Beatriz; Vasconcelos, Isabel; Mendes-Faia, Arlete; Mendes-Ferreira, AnaNon-Saccharomyces yeasts include different species which comprise an ecologically and biochemically diverse group capable of altering fermentation dynamics and wine composition and flavour. In this study, single- and mixed-culture of Hanseniaspora guilliermondii and Saccharomyces cerevisiae were used to ferment natural grape-juice, under two nitrogen regimes. In single-culture the strain H. guilliermondii failed to complete total sugar breakdown even though the nitrogen available has not been a limiting factor of its growth or fermentative activity. In mixed-culture, that strain negatively interfered with the growth and fermentative performance of S. cerevisiae, resulting in lower fermentation rate and longer fermentation length, irrespective of the initial nitrogen concentration. The impact of co-inoculation on the volatile compounds profilewasmore evident in thewines obtained from DAP-supplementedmusts, characterised by increased levels of ethyl and acetate esters, associated with fruity and floral character of wines. Moreover, the levels of fatty acids and sulphur compounds which are responsible for unpleasant odours that depreciate wine sensory quality were significantly lower. Accordingly, data obtained suggests that the strain H. guilliermondii has potential to be used as adjunct of S. cerevisiae in wine industry, although possible interactions with S. cerevisiae still need to be elucidated.
- Machine learning techniques disclose the combined effect of fermentation conditions on yeast mixed-culture dynamics and wine qualityPublication . Barbosa, Catarina; Ramalhosa, Elsa; Vasconcelos, Isabel; Reis, Marco; Mendes-Ferreira, AnaThe use of yeast starter cultures consisting of a blend of Saccharomyces cerevisiae and non-Saccharomyces yeasts has increased in recent years as a mean to address consumers’ demands for diversified wines. However, this strategy is currently limited by the lack of a comprehensive knowledge regarding the factors that determine the balance between the yeast-yeast interactions and their responses triggered in complex environments. Our previous studies demonstrated that the strain Hanseniaspora guilliermondii UTAD222 has potential to be used as an adjunct of S. cerevisiae in the wine industry due to its positive impact on the fruity and floral character of wines. To rationalize the use of this yeast consortium, this study aims to understand the influence of production factors such as sugar and nitrogen levels, fermentation temperature, and the level of co-inoculation of H. guilliermondii UTAD222 in shaping fermentation and wine composition. For that purpose, a Central Composite experimental Design was applied to investigate the combined effects of the four factors on fermentation parameters and metabolites produced. The patterns of variation of the response variables were analyzed using machine learning methods, to describe their clustered behavior and model the evolution of each cluster depending on the experimental conditions. The innovative data analysis methodology adopted goes beyond the traditional univariate approach, being able to incorporate the modularity, heterogeneity, and hierarchy inherent to metabolic systems. In this line, this study provides preliminary data and insights, enabling the development of innovative strategies to increase the aromatic and fermentative potential of H. guilliermondii UTAD222 by modulating temperature and the availability of nitrogen and/or sugars in the medium. Furthermore, the strategy followed gathered knowledge to guide the rational development of mixed blends that can be used to obtain a particular wine style, as a function of fermentation conditions.
- Promoting sustainability in Mediterranean agriculture: insights from the Portuguese vine and wine sectorPublication . Oliveira, Manuel João; Santos, Cátia; Barbosa, Catarina; Gonçalves, Igor; Soares, Rui; Pereira, Sofia; Castro, PaulaAgroecology is an integrated approach that simultaneously applies ecological and social concepts and principles to redesign and manage food and agricultural systems, promoting agroecosystems with the necessary biological, socio-economic, and institutional diversity and alignment to support greater efficiency. The present study aimed at characterising the socio-economic factors that lead farmers to accept and adopt more sustainable practices. Herein, we have addressed technical and economic aspects, in an integrated manner, in order to demonstrate the benefits of sustainable agroecosystems focused on Mediterranean crops. To achieve this, a survey was conducted to map and characterise viticultural practices in Portuguese vineyards, as well as winegrowers’ perception regarding the acceptance and implementation of alternative agricultural practices. The questionnaire also identified some barriers and opportunities for the application and adoption of alternative agricultural practices toward sustainable agriculture, considering technical and socio-economic aspects, vineyard characteristics, agricultural practices, and farmers' educational level. Winegrowers identified climate change adaptation and biodiversity preservation as the most important benefits of implementing alternative practices. Additionally, they demonstrated awareness of the importance of adopting alternative viticultural practices, especially for environmental improvement (biodiversity and natural resources conservation), as well as for increased sustainability of their operations/vineyards and greater profitability (e.g., through wine tourism). It was also possible to perceive that most respondents had a very clear and objective perception of what alternative practices are, even though showing some difficulty in changing habits and work techniques, loss of profitability, and increased production costs. Altogether, our study highlights that Portuguese winegrowers are aware of the importance of agroecological practices, such as sexual confusion, no-till farming, ecological corridors, and the preservation of biodiversity (e.g. insect shelters), reinforcing their position in adopting these approaches for the expansion of agroecology in the context of the ongoing reforms of European Agricultural Policy.