Cork structural characteristics and their influence on the oxygen ingress through wine stoppers

Doutoramento em Engenharia Florestal e dos Recursos Naturais - Instituto Superior de Agronomia - UL

Red wine sweetness preference according to consumer segmentation

The present work aims to evaluate the acceptance and preference for sweet taste in red wine, according to consumer segmentation in age, gender, personality type, tasting sensitivity and consumer experience in wine. A hundred and fourteen wine tasters were invited to the wine tasting, and the average age was 27 years. An addition of sugar was made with equal concentrations of glucose and fructose to the wine at 2g/L, 4g/L, 8g/L, 16g/L and 32g/L. Five pairs of glasses were presented for the subjects to taste containing each a control wine and a spiked sample. Pairs were presented in order of concentration, from 2g/L to 32g/l. The subjects were also asked to answer two online questionnaires at the end of the tasting, on the personality types and vinotype, which is related to mouth sensitivity. ISO-5495 paired comparison tests were used for sensorial analysis. The objective was to assess if any of the nine segmentation factors had influence on preference or rejection for spiked samples and to establish whether this preference was statistically significant. We concluded that it would be important to have subjects with an age average higher than 27 years and more experienced in wine drinking, mostly because the data relative to preferences in novices shows some dispersion and lack of attention. A panel of older and more experienced wine tasters is likely to be more attentive and focused and therefore yield differentiated results. It was also concluded that more research is required to extend this investigation to other wine styles because the differences in preferences can depend on other reasons, such as preferring a wine with more or less sugar according to the type of wine. Finally it was concluded also that some variables influence preference for sweet taste in red wine, such as gender, vinotype and category of experience

Development of the composition of oak wood during seasoning and its impact on wine

Mestrado Vinifera Euromaster - Instituto Superior de Agronomia - UL

Development of a new wine tasting method based on emotional responses

Mestrado Vinifera Euromaster - Instituto Superior de Agronomia - UL

Use of alternative wood chips from new botanical species. Their impact on phenolic composition and sensory properties of a white wine from Encruzado grape variety

Mestrado Vinifera Euromaster - Instituto Superior de Agronomia - UL

Reading keys in the communication of wine in China. Wine marketing strategies

Mestrado Vinifera Euromaster - Instituto Superior de Agronomia - UL

Economic efficiency of members of protected designations of origin: sharing reputation indicators in the experience goods of wine and cheese

The aim of this paper is to analyse the economic efficiency of members of protected designations of origin (PDO). For the first time we analyse the value of PDO labels from the point of view of economic efficiency. The central hypothesis is that a PDO has a positive impact on the economic efficiency of its member companies and that this is because a PDO label is a collective reputation indicator that foments efficient investment in quality in terms of member returns. The methodology applied to test this hypothesis is based on data envelopment analysis to estimate economic efficiency, and econometric models to explain company efficiency through both the PDO label, as an indicator of collective reputation, and the characteristics of the company. The results obtained in the experience goods of wine and cheese in Spain show that PDO labels have a positive impact on economic efficiency. Additionally, the age and size of the company have a positive effect while the wage level of the company has a different influence on efficiency depending on the sector considered. Overall, the results reveal the importance of PDOs in industries in which the signal of reputation is not only reliant on the individual brands.

Wine phenolics: looking for a smooth mouthfeel

Each grape variety has its own phenolic profile. However, the concentration of the phenolic compounds present in wine mainly dependson winemaking processes. Phenolic compounds influence wine sensorial characteristics namely taste or mouthfeel, bitterness, astringency and color. Humans can perceive six basic tastes: sweet, salty; sour; umami; fat-taste and bitter taste. This last basic taste is considered as a defense mechanism against the ingestion of potential poisons. Some of the genes,encoding G-protein-coupled receptors - TAS2Rs, which translate for these distinct bitter compounds detectors have been identified. Different phenolic compounds activate distinguished combination of TAS2Rs. Astringency in wine is primarily driven by proanthocyanidins, soluble protein-proanthocyanidins complexes which diminish the protective salivary film and bind to the salivary pellicle; insoluble protein-proanthocyanidins complex and proanthocyanidins are rejected against salivary film and trigger astringency sensation via increasing friction. Thus, the aim of this review is to expand the knowledge about the role of wine phenolic compounds in wine sensorial properties, namely in bitterness and astringency phenomenon’s.

Grape and Wine Metabolites: Biotechnological Approaches to Improve Wine Quality

Grape metabolites can be affected by many extrinsic and intrinsic factors, such as grape variety, ripening stage, growing regions, vineyard management practices, and edaphoclimatic conditions. However, there is still much about the in vivo formation of grape metabolites that need to be investigated. The winemaking process also can create distinct wines. Nowadays, wine fermentations are driven mostly by single-strain inoculations, allowing greater control of fermentation. Pure cultures of selected yeast strains, mostly Saccharomyces cerevisiae, are added to grape must, leading to more predictable outcomes and decreasing the risk of spoilage. Besides yeasts, lactic acid bacteria also play an important role, in the final wine quality. Thus, this chapter attempts to present an overview of grape berry physiology and metabolome to provide a deep understanding of the primary and secondary metabolites accumulated in the grape berries and their potential impact in wine quality. In addition, biotechnological approaches for wine quality practiced during wine alcoholic and malolactic fermentation will also be discussed.

Recent Developments in Wine Tartaric Stabilization

Tartrate precipitation is still a relevant subject in Enology, being one of the most common problems of wine physical-chemical instability. Potassium bitartrate and calcium tartrate precipitations are undesirable phenomena which can occur in bottled wines, especially when these are stored at low temperatures. The occurrence of tartrate salt crystals (potassium hydrogen tartrate – KHT and calcium tartrate – CaT) in bottles has severe consequences in the final aspect of the wine and therefore on the consumer’s acceptance, making tartrate wine stabilization virtually mandatory before bottling. Currently, several solutions to prevent this haze are available: subtractive methods including the conventional cold treatments that promote the cristalization of KHT, removal of potassium and calcium ions either by electrodialysis or ion exchange resins; and additive methods such as the addition of carboxymethylcellulose, mannoproteins or metatartaric acid. For monitoring the KHT stability, several analytical methods have been developed based on conductivity evaluation, namely the mini-contact test and the saturation temperature measurements (TS). These methods will also be revisited, aiming to raise awareness of their utility as tools in quality control of wines. This review addresses tartrate precipitation subject and the most recent preventive solutions available, pointing out the advantages and drawbacks of each one, and its impact on the final characteristics of the wine.

Evaluation of the evolution of the anthocyanins profile in red wine grape varieties in Alentejo

The flavonoids (including anthocyanins) are wine compounds with important anti-oxidant activity, protecting the cells against oxidative processes, preventing cardiovascular and neurodegenerative diseases, cancer, among others (Antoniolli et al. 2015; Castañeda-Ovando et al. 2009; Hosu et al. 2014; Huang et al. 2009; Kong et al. 2003). Anthocyanins in grapes at harvest are determinant to red wine quality and their development in the grape must be characterised in order to determine the most suitable date for the harvest. Thus the aim of this research is the evaluation of anthocyanins composition in two red wine grape varieties from véraison continuing through ripening. Anthocyanins were quantified by high resolution liquid chromatography (HPLC-DAD). Additionally, the total phenols content were quantified by UV-Vis Spectrometry. The anthocyanins’ profile evolution may be dependent on the variety and ripening phase. During ripening grape samples have shown an increase of coumaryl derivatives. This information may lead us to understand the anthocyanins biosynthesis pathway in different grape varieties. The development of anthocyanins from the véraison seems to follow a pattern that coincides with the increasing accumulation of soluble sugars.

Nitrate and potassium concentration in fertigated soil cultivated with wine vines.

In the semiarid region of Brazil the use of irrigation systems for applying fertilizers in horticulture is the primary means for incorporating nutrients in the soil. However, this technique still requires its use in wine vines to be assessed. In view of this, this study aimed to assess nitrate and potassium concentrations in soil fertigated with nitrogen and potassium fertilizers in 3 wine grape growing cycles. A field experiment was conducted with ?Syrah? wine grapes, in Petrolina, Pernambuco, Brazil; it assessed five nitrogen doses (0, 15, 30, 60 and 120 kg ha-1) and five K2O doses (0, 15, 30, 60 and 120 kg ha-1) applied by drip irrigation system with two emitters per plant, with a flow rate of 4 L h-1. The experimental design used was the factorial split-plot, making up 13 combinations arranged in 4 randomized blocks. Soil solution samples were collected weekly with the aid of porous cup extractors for all treatments and at depths of 0.4 and 0.6 m by determining nitrate and potassium concentrations and electrical conductivity. Increased levels of both nutrients in the irrigation water increased the availability of nitrate and potassium in the soil solution. The highest nitrate and potassium concentrations were found in the second growing cycle at both depths studied.

The development of the viticulture for a high quality tropical wine production in the world.

2011

Climatic groups in Ibero-America viticulture compared to worldwide wine producer regions.

The wine production is an important activity in many Ibero-American countries. The wine producer regions of these countries configure a large use of different climate types and viticultural climates. In a vitivinicultural zoning project of CYTED (Ibero-American Program for Science, Technology and Development), a viticultural climatic characterization was done in this macro viticultural region. The project have assembled a climatic database that characterizes the viticultural regions, including relevant variables for viticulture: air temperature (mean, maximum, and minimum), precipitation, relative humidity, solar radiation, number of sunshine hours, wind speed, and evapotranspiration. Using indices of the Geoviticulture MCC System (HI, CI and DI), more than 70 viticultural regions in different countries (Argentina, Bolivia, Brazil, Chile, Cuba, Spain, Mexico, Peru, Portugal and Uruguay) were characterized according to its viticultural climatic. The results, which will be integrated to the worldwide database of the MCC System, showed that the Ibero-American viticulture is placed in a wide range of climatic groups of the wine producing regions around the world. This article presents the climatic groups found in Ibero-America, identifying also some new climatic groups not yet found in other regions of the world. This work also identifies some climatic groups not found in Ibero-America viticulture. The research has also highlighted viticultural areas characterized by climates with ?intra-annual climatic variability?, with the potential to produce more than one growing cycle per year. The results allow to conclude that the wide variability and climatic diversity present in Ibero-America may be one of the reasons to explain the diversity in terms of wine types, sensorial characteristics, typicity and uniqueness of wines produced on this macro-region.

High altitude wine in Santa Catarina, Brazil: a collective brand.

2010