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- History of persistence and diversification of grape varieties in the region of Tras-os-Montes, NE PortugalPublication . Alves, Vítor Fernando Silva Simões; Andrade, João Verdial; Barreales, David; Ribeiro, A.C.According to a physiocrat memoirist of the late eighteenth century, "... the vines to be panted should not be from a single species but from different ones ...; and will be planted more of those that are of better quality." This recommendation was intended to induce farmers to plant a number of grape varieties, as diverse as possible, but within a reasonable numerical criterion. So they would be safe from the variation of annual productivity of different varieties, since one could produce more and others little or nothing. However, this plantation and controlled choice of varieties, was not always carried out. Documentary sources report that there was "... great abuse so the choice of land, as in planting a very excessive number of different varieties." In the province of “Beira” in Lamego (NE of Portugal), there were 67 varieties of grapes, "29 white and 18 black" and in Tras-os-Montes about 30, among white and red. Thus, this implied that at the harvest time some grapes were passed, other rotten and others still without getting to its perfect state of "maturity". It is considered, therefore, that this mix is reflected in the type of wine that the same grapes were to produce and that was variable from place to place within the same region It was considered therefore that this mixture would be reflected on the type of wine that the same grapes were to produce and that was variable from place to place within the same region. Production and varied wine because the grapes were "from many varieties" which adapted better or worse, to the land where they were planted. There were vines which gave best in “hot land”, while others prefer the “cold land”. Here is a lot of varieties planted in the region in the sixteenth century: “bastardo, trincadente, agudelho, Álvaro de Sousa (Malvasia), castelão, lourelo, verdelho preto, verdelho branco, donzelinho, terrantês, abelhal, burral, samarrinho tinto, ferral, ceitão, mourisco e folgazão”. A considerable multiplicity that included wine grapes, white and red, and table grapes. According to the classical author (Palladius) "... the farmer or want to have grapes to eat, or to produce wine; in the first case should plant vines that produce large berries grapes, and hard, as are ... “the grapes “ferais” the “ceitãs”, or “moscatel de Jesus”, the “dedo de dama”, and more. In the latter case, to choose the vines that give grapes with thin skin, and tasty, and especially those to whom the flower fall very first than the other. " So, would be necessary to end the referred mixtures of varieties to "improve the goodness of the wines" and the farmers should meet the quality of the grapes to harvest the best wines. According to information from the eighteenth century, "The grapes called Alvarelhão, pé agudo preto, tinta-cão, e sousão make a strong wine, full-bodied, of good taste; the “bastardo” and Donzelinho, together in small quantities with the other varieties sweeten and soften the harshness of Alvarelhão and Sousão, and increase them the softness of the aroma. " At this time, including the Douro region, there was a strong disbelief of some varieties which would assume later a great importance, not only in the region but in rest of Portugal, and even in the world. We refer to the varieties "... tourigo, tintacastelão, tinta-borraçal and others so-called thick-red, which regularly fruit in abundance, but the wine which makes them is weak and tasteless, and consequently with less duration". The objective of this study is the identification of the varieties of the Tras-os-Montes region, carry out its local territorial delimitation, in different ages, and make progress in identifying synonyms. Subsequently, will be performed a comparability study in the use of grape varieties in the same places, between the historical data and the remaining (very) old vineyards.
- Mead production: comparison of different production scales (preliminary results)Publication . Gomes, Teresa; Barradas, Carla; Dias, Teresa; Andrade, João Verdial; Morais, Jorge Sá; Ramalhosa, Elsa; Estevinho, Leticia M.Mead production represents a possible economic alternative to honey producers that intend to obtain honey products with surplus value. From that the present work aims to study the influence of using different production scales on the quality of the final mead obtained and on the process performance. Increasing the production scale almost ten times (1.5 to 20 L), some differences were observed. Maximum specific growth rates equal to 0.045 and 0.038 h-1 were obtained for fermentations carried out at 1.5 and 20 L, respectively. The time course of glucose and glycerol were similar for both production scales. Nevertheless, slight differences at the end of the fermentations were observed for fructose and acetic acid. In relation to ethanol, a higher final concentration was found in the pilot-scale, resulting in a higher ethanol yield. In conclusion, these preliminary results are a good promise to local honey producers who intent to obtain large-productions of mead.
- Influence of pruning system and deficit irrigation on grapevine physiology, yield and grape quality of cv. Sousão (Vitis vinifera L.) growing under Mediterranean conditionsPublication . Barreales, David; Capitão, Susana dos Anjos; Monteiro, Ângela Marina Alves; Andrade, João Verdial; Ribeiro, A.C.Different strategies are currently being sought to mitigate the effects of grapevine summer water stress. Regulated Deficit Irrigation (RDI) is a strategy that has been successfully adapted. Also, some pruning systems have been identified as capable of influencing vine water balance. The aim of this work was to evaluate the effect of two RDI strategies and two pruning systems on grapevine physiology, yield and grape quality of the Sousão variety grown under Mediterranean conditions. This study was conducted in an organic vineyard in northeastern Portugal (41º31´N; 7º5´W; 326 m a.s.l.), planted in 2011 with 1103 P rootstock. The pruning systems, single Cordon and single Guyot were established in 2013. In 2019, three irrigation treatments were implemented: a full irrigation control, FI (100% ETc), and two deficit irrigations treatments, RDI25 (25% ETc) and RDI50 (50% of ETc). During the growing season, grapevine water status and physiological parameters were monitored. At harvest, yield, yield components, and grape composition were evaluated and analyzed. The results showed that the vines under an RDI regime presented significantly lower leaf water potential values than those under FI in both pruning systems. Therefore, the physiological performance was affected by decreasing its stomatal conductance, transpiration, and photosynthesis. However, the lower physiological performance did not significantly affect yield. No significant differences were observed in total soluble solids and total acidity regarding the grape composition. However, there was an increase in anthocyanins and phenolic compounds in grapes with less irrigation.
- Mead production: comparison of different production scales (preliminary results)Publication . Gomes, Teresa; Barradas, Carla; Dias, Teresa; Andrade, João Verdial; Morais, Jorge Sá; Ramalhosa, Elsa; Estevinho, Leticia M.Mead production represents a possible economic alternative to honey producers that intend to obtain honey products with surplus value. From that the present work aims to study the influence of using different production scales on the quality of the final mead obtained and on the process performance. Increasing the production scale almost ten times (1.5 to 20 L), some differences were observed. Maximum specific growth rates equal to 0.045 and 0.038 h-1 were obtained for fermentations carried out at 1.5 and 20 L, respectively. The time course of glucose and glycerol were similar for both production scales. Nevertheless, slight differences at the end of the fermentations were observed for fructose and acetic acid. In relation to ethanol, a higher final concentration was found in the pilot-scale, resulting in a higher ethanol yield. In conclusion, these preliminary results are a good promise to local honey producers who intent to obtain large-productions of mead.
- Phenolic composition and antioxidant potential of Vitis vinífera leaves of six varieties harvested in Northeast of PortugalPublication . Ramalhosa, Elsa; Valentão, Patrícia; Andrade, Paula B.; Andrade, João Verdial; Bento, Albino; Pereira, J.A.In the present work it was intended to study the phenolic composition and antioxidant potential of Vitis vinifera leaves of six varieties: white – Carrega Branco, Chardonnay and Viosinho, and red – Bastardo, Tinta Gorda and Touriga Francesa. All varieties were harvested in the NE of Portugal (Trás-os-Montes region). The phenolic composition of aqueous extracts was determined by HPLC-DAD and the antioxidant potential was evaluated by the total reducing capacity (TRC), reducing power, DPPH radical scavenging and hydroxyl radical-scavenging activity assays. Six phenolic compounds were detected, namely: trans-caffeoyltartaric acid, trans-coumaroyltartaric acid, myricetin-3-O-glucoside, quercetin-3-O-glucoside, quercetin-3-O-galactoside and kaempferol-3-O-glucoside. The sum of these compounds varied between 23918 and 36859 mg/kg extract (dry basis) for the white varieties and 29706 and 43325 mg/kg extract (dry basis) for the red varieties. Regarding TRC, the white and red varieties displayed the following antioxidant capacities: 203 to 550 and 222 to 360 mg GAE/g extract, respectively. Some differences among the six varieties were observed in what concerns the reducing power and DPPH radical scavenging capacity. The highest values of reducing power were observed for Chardonnay (white) and Touriga Francesa (red) varieties. On contrary, the highest DPPH radical scavenging capacities were observed for the Viosinho (white) and Tinta Gorda (red) varieties. All extracts presented hydroxyl radical scavenging activity, being the Carrega Branco (white) variety the one that presented the highest potential.
- Climate change potential effects on grapevine bioclimatic indices: a case study for the Portuguese Demarcated Douro Region (Portugal)Publication . Blanco-Ward, Daniel; Ribeiro, A.C.; Barreales, David; Castro, João Paulo; Andrade, João Verdial; Feliciano, Manuel; Viceto, Carolina; Rocha, Alfredo; Carlos, CristinaIn this work bioclimatic parameters and indices relevant to the grapevine are estimated for the years 2000 (past-recent), 2049 (medium-term future) and 2097 (long-term future), based on high resolution (1 km x 1 km) MPI-WRF RCP 8.5 climate simulations. The selected parameters and indices are mean temperature during the grapevine period (April to October), cumulative rainfall during the grapevine period, Winker index (IW), Huglin heliothermic index (IH), night cold index (IF) and dryness index (IS). In general, a significant increase in mean temperature during the grapevine period is observed, together with a significant decrease in precipitation. The present IW is associated with the production of high quality wines; the higher values predicted for the future represent intensive production of wines of intermediate quality. The IH show the passage of a growing region of the vine considered as hot-temperate to a warm category of higher helio-thermicity. At present, IF indicates very cool conditions (associated with quality wines), while in the future there is a tendency for temperate nights. Finally, IS indicates an increase in water stress considered already high in the present climate. An assessment on the statistical significance of climatic indices, their differences between the historical and the future scenarios and the potential impact on wine production is performed. Preliminary results indicate increased climatic stress on the Douro region wine production and increased vulnerability of its vine varieties. These results will provide evidence for future strategies aimed to preserve the high-quality wines in the region and their typicality in a sustainable way.
- Effects of irrigation and collection period on grapevine leaf (Vitis vinifera L. var. Touriga Nacional): Evaluation of the phytochemical composition and antioxidant propertiesPublication . Barreales, David; Malheiro, Ricardo; Pereira, J.A.; Andrade, João Verdial; Bento, Albino; Casquero, Pedro Antonio; Ribeiro, A.C.The cultivation of grapevines (Vitis vinifera L.) has extended worldwide, with great economic importance. From this crop, we can obtain grapes for fresh consumption, raisins, juices, wine, and other derived products. The cultivation of grapevines also generates some byproducts, such as seeds, skins, wood and leaves. The leaves can be removed from the plant, as is common agricultural practice, to improve the production and quality of the grapes at certain periods in the crop cycle. In the present work, the phytochemical composition (total phenols content, hydroxycinnamic acids derivatives and flavonols) and antioxidant potential (reducing power, ABTS and DPPH radical scavenging capacity) of grapevine leaves from cv. Touriga Nacional were evaluated. The studied cultivar was under three severities of regulated deficit irrigation (RDI60, RDI40, and RDI20; providing 60, 40 and 20% of reference evapotranspiration, respectively) and non-irrigation (NI; exclusively rain-fed), in a vineyard located in the Demarcated Douro Region (Portugal). The leaves were collected at three different phenological stages: veraison, maturation, and grape harvest. For the first time, the interactions between different irrigation regimes and the collection period were evaluated on grapevine leaves. The results obtained for the phytochemical composition revealed that increasing irrigation reduced total phenols content, hydroxycinnamic acids derivatives, and flavonols in all of the phenological stages studied. For instance, compared to that of the control treatment (NI), the total phenols content reduced 19% in RDI20 (from 189 mg GAE g−1 to 153 mg GAE g−1), 28% in RDI40 (136 mg GAE g−1), and 33% in RDI60 (127 mg GAE g−1). The antioxidant activity suffered a reduction when the irrigation amount was increased for all assays. Additionally, the antioxidant activity suffered a reduction over time, presenting higher values in veraison. For harvest sampling, the loss of antioxidant activity was more notable, with EC50 values varying between 0.092 mg mL−1 (NI) and 0.187 mg mL−1 (RDI60). Altogether, the results suggest that grapevine leaves are a potential source of natural compounds with valuable antioxidant properties that could be explored by the pharmaceutical, chemical and food industries.
- Influência da rega deficitária na evolução da maturação da variedade Tinta Roriz (Vitis vinifera L.)Publication . Ribeiro, A.C.; Sá, Alexandra; Andrade, João VerdialNa Região Demarcada do Douro, e em particular na sub-região do Douro Superior, a vinha é conduzida, durante uma parte significativa do seu ciclo vegetativo, em condições de défice hídrico acentuado associadas a altas temperaturas, elevado stresse radiativo e elevado défice de pressão de vapor. As práticas culturais implementadas para minimizar as condições adversas, e em particular o regime de rega, podem alterar substancialmente a fisiologia da videira afectando a produção e a composição do bago. O principal objectivo deste estudo foi o de avaliar o curso da maturação na variedade Tinta Roriz de Vitis vinífera L., através da monitorização dos principais parâmetros da maturação, quando submetida a dotações de rega moderadas.
- Importância dos inimigos associados à oliveira para azeitona de conserva no planalto mirandêsPublication . Bento, Albino; Andrade, João Verdial; Ribeiro, A.C.; Rodrigues, M.A.; Cabanas, J.E.; Pereira, J.A.Em Trás-os-Montes, a oliveira É uma das culturas mais importantes. Nesta região, a maioria da produção de azeitona e destinada à obtenção de azeite. Contudo, nos concelhos de Freixo de Espada à Cinta e Mogadouro, a quase totalidade da produção é destinada para azeitona de conserva podendo ser certificada como "Azeitona de Conserva Negrinha de Freixo" DOP.
- Pesquisa de resíduos de fungicidas no mosto e no vinhoPublication . Pinto, Miguel; Pereira, Sandra; Fernandes, Conceição; Andrade, João Verdial; Estevinho, Leticia M.