Browsing by Author "Vilela, Alice"
Now showing 1 - 10 of 19
Results Per Page
Sort Options
- Aplicação de revestimentos na castanhaPublication . Ramalhosa, Elsa; Pereira, Ermelinda; Laranjo, José Gomes; Ferreira-Cardoso, Jorge; Gomes, A.; Vilela, Alice; Sampaio, Ana; Nunes, Fernando M.No presente capítulo pretende-se descrever as atividades realizadas no âmbito do Projeto ValorCast ao nível da aplicação de revestimentos hidrofílicos e hidrofóbicos com o intuito de reduzir a desidratação das castanhas após a colheita. Para a avaliação de revestimentos hidrofílicos foram realizados quatro estudos, nos quais se avaliou a aplicação dos seguintes compostos: (i) alginato, quitosano e proteína do soro, a 2% (m/v); (ii) quitosano (0,5, 1 e 2%, m/v) e farinha de mandioca (3 e 5%, m/v); (iii) revestimentos comerciais da empresa DOMCA, designadamente o FOOD-COAT®, PROALLIUM® e ambos em conjunto. Na aplicação de revestimentos de resíduos hidrofóbicos utilizou-se a parafina, parafina aditivada com timol e a cera de abelha. Através da realização do primeiro estudo verificou-se que os melhores resultados em termos da qualidade microbiológica do fruto foram obtidos com o quitosano. No segundo estudo observou-se que a aplicação de farinha de mandioca a 5% acarretou o aparecimento de bolores visíveis após 6 meses de armazenamento. Pelo contrário, a aplicação de quitosano a 1 e 2% e farinha de mandioca a 3% forneceram resultados promissores ao nível da redução do desenvolvimento microbiano, principalmente quando se consideram armazenamentos longos (> 3 meses). No terceiro estudo verificou-se que em relação à perda de peso, após o armazenamento durante 4 meses, o FOOD-COAT® foi o revestimento que mostrou o melhor desempenho, com a menor perda de peso (5 a 6%). No entanto, em relação aos microrganismos mesófilos aeróbios e bolores e leveduras, o PROALLIUM® foi o mais eficiente durante dois a três meses. Assim, a junção PROALLIUM®+ FOOD-COAT® pode ser vantajosa para se retardar a perda de peso e o desenvolvimento microbiano até três meses de armazenamento, perdendo a sua eficácia após esse período. Relativamente aos revestimentos hidrofóbicos à base de parafina e cera de abelha foram muito eficientes na prevenção da perda de água quando as castanhas foram armazenadas em condições forçadas. As castanhas revestidas com parafina ou com cera de abelha em termos sensoriais foram idênticas às castanhas antes do armazenamento, exceto com a adição do timol no tratamento da parafina pois conferiu aromas desagradáveis à castanha, provavelmente devido ao odor pungente do timol, mas em termos microbiológicos o timol teve uma ação essencial, pois permitiu diminuir a podridão das castanhas após o armazenamento.
- Comparison of ion exchange resins at industrial scale and enological stabilizers treatments for tartaric stabilization of white Port wine: Impact on wine physicochemical and sensory profilePublication . Moreira, Daniela; Fernandes, Conceição; Borges, Rita; Marques, Celeste; Matos, Carlos; Vilela, Alice; Filipe-Ribeiro, Luis; Nunes, Fernando M.; Cosme, FernandaA frequent cause cause of stability loss in awine is the formation of crystalline salts of potassium bitartrate (KHT) that appears mainly at low temperatures, temperatures, as a consequence of a large decrease in its itssolubility solubility [1,2]. Port wine is a Portuguese fortified wine produced exclusively in the Douro Valley demarcated region. There are only only few few studies regarding white Port wine tartaric stabilization, although its importance for consumers acceptance.
- Comparison of ion exchange resins at industrial scale and enological stabilizers treatments for tartaric stabilization of white Port wine: Impact on wine physicochemical and sensory profile.Publication . Moreira, Daniela; Fernandes, Conceição; Borges, Rita; Marques, Celeste; Matos, Carlos; Vilela, Alice; Filipe-Ribeiro, Luis; Nunes, Fernando M.; Cosme, FernandaA frequent cause of stability loss in a wine is the formation of crystalline salts of potassium bitartrate (KHT) that appears mainly at low temperatures, as a consequence of a large decrease in its solubility [1, 2]. Although important for consumer’s acceptance, there are only few studies regarding white Port wine tartaric stabilization. Therefore, tartaric stabilization has been carried out in a white Port wine by ion exchange resins, at an industrial scale, and by the addition of enological stabilizers, with the main objective of comparing the impact of these treatments on wine physicochemical and sensory profile. Port wine is a Portuguese fortified wine produced exclusively in the Douro Valley demarcated region. In this study, a white Port wine from the 2015 vintage from Gran Cruz winery, Portugal was used and almost 20% from the total wine volume was treated by ion exchange resins (pH-Stab®). The stabilizers used were metatartaric acid and carboxymethylcellulose (CMC1 5%, CMC2 20%; CMC3 solid) with different structural characteristics. Wine tartaric stability was measured by the mini contact test. Wines phenolic composition - total phenols, flavonoid and non-flavonoid compounds, as well as the chromatic characteristics by the CIELab method, were also evaluated. Sensory analysis was performed by a panel of eight trained tasters. Twenty-one attributes were selected and were quantified using a five-point intensity scale. As expected, all treatments assayed stabilized the white Port wine. All the samples presented a slight decrease in total phenolic compounds and non-flavonoid phenolic compounds. Concerning sensory analysis, wine treatment with ion exchange resins was more scored for the visual limpidity attribute and for the aroma attributes citrus and tea.
- Efeito da rega e da aplicação de caulino nas características sensoriais e parâmetros de biometria da amêndoaPublication . Prgomet, Iva; Barros, Ana I.R.N.A.; Pascual-Seva, Núria; Oliveira, Ivo; Morais, Maria Cristina; Afonso, Sílvia Martins; Bernardo, Sara; Ribeiro, A.C.; Barreales, David; Victor, João; Silva, A.P.; Vilela, Alice; Gonçalves, Berta C.C.Em Portugal, a amêndoa é uma cultura tradicional, que se encontra distribuída pelas regiões do Alentejo, Algarve e Trás-os-Montes, sendo, juntamente com a castanha, a mais produzida dos frutos de casca rija. Os amendoais são geralmente tradicionais, de sequeiro, sem técnicas de cultivo adequadas, o que leva a um baixo rendimento de produção. A produtividade, bem como a qualidade dos frutos, podem aumentar com a utilização das técnicas culturais como a irrigação e aplicação de substâncias, como o caulino, para mitigação dos efeitos de stresse estival. No presente estudo, diferentes regimes de rega (100% de ETC, 70% de ETC, 35% de ETC, 100%-35% de ETC, controlo sem rega) e caulino (4%) foram aplicados durante o verão de 2015, em amendoeiras da cultivar Ferragnés situadas no Norte de Portugal (Alfândega da Fé). Foram avaliados os efeitos destes tratamentos na biometria do fruto, nas características sensoriais, no rendimento de produção e na produtividade. Verificou-se que, no caso das amendoeiras regadas com 100% de ETC, se obteve uma maior produtividade, apesar de os parâmetros da biometria das amêndoas se terem revelado mais baixos. A maior ou menor disponibilidade de água forneceram às amêndoas atributos sensoriais que as diferenciam. Assim, a rega a 35% e 100%, tornaram as amêndoas mais doces, ao passo que a falta de água (sem rega), tornou as amêndoas mais rugosas. A presença de caulino nas folhas e "rega- 70% ou 100-35%" favoreceu a cor mais escura e a dureza dos frutos em estudo.
- Effect of ion exchange resins on white and red wine pH: Impact on wine sensory characteristicsPublication . Borges, Rita; Fernandes, Conceição; Marques, Celeste; Matos, Carlos; Vilela, Alice; Filipe-Ribeiro, Luis; Nunes, Fernando M.; Cosme, FernandaThe pH control during winemaking is a fundamental parameter by their influence on color, freshness and to achieve wine microbiological stability. The most common acidify correction performed in wineries is addition of natural tartaric acid; however, in some cases, this operation increases the risks of potassium bitartrate precipitations [1, 2]. The application of ion exchange resins for wine acidification is based on ability of exchanging ions fixed on functional groups, namely by exchanging cations, such as potassium, with hydrogen ions. Nevertheless, there is an important lack of knowledge on the impact of this operation on wine sensory characteristics. To adjust wine pH, a certain amount of treated wine by ion exchange resins is mixed with the untreated wine [3]. According to OIV [4], treatment must not lower the pH of wine below 3.0 and the decrease should not exceed 0.3 pH units. Anion exchangers are not allowed by the OIV [3] due to the negative effects on the wine sensory quality [5,6]. Therefore, the aim of this work was to evaluate the effect of cation exchange resins, authorized by the OIV, according to Resolution 43/2000 [3] on wine pH control and to evaluate their impact on wine sensory quality at industrial scale. In this study a white and a red wine from the Douro Valley region, 2015 vintage, was used. In this work ion exchange resin treated white wine was almost 20% from total white wine volume and red wine was almost 30% from total red wine volume. The present study indicated that there were no considerable changes in sensory attributes, although a slight improvement in the aroma and taste, as a result of the ion-exchange pH adjustment. These results show that the application of ion exchange resins process to wine could be an interesting tool for white and red wine pH adjustment, without interfering with wine sensorial quality.
- Effect of ion exchange resins on white and red wine pH: Impact on wine sensory characteristicsPublication . Borges, Rita; Fernandes, Conceição; Marques, Celeste; Matos, Carlos; Vilela, Alice; Filipe-Ribeiro, Luis; Nunes, Fernando M.; Cosme, FernandaThe pH control during winemaking is a fundamental parameter by their influence on colour, freshness and to achieve wine microbiological stability. The application of ion exchange resins for wine acidification is based on ability of exchanging ions fixed on functional groups, namely by exchanging cations, such as potassium, with hydrogen ions. Nevertheless, there is an important lack of knowledge on the impact of this operation on wine sensory characteristics. Therefore, the aim of this work was to evaluate the effect of cation exchange resins, on wine pH control and to evaluate their impact on wine sensory quality at industrial scale. In this study a white and a red wine, both from the Douro Valley demarcated region, 2015 vintage, were used. The ion exchange resin treated wine was almost 20% from total white wine volume and almost 30% from total red wine volume. The results obtained in the present study indicated that there were no considerable changes in sensory attributes, although a slight improvement in the aroma and taste, as a result of the ion-exchange pH adjustment. Therefore, the application of ion exchange resins process to wine could be an interesting tool for white and red wine pH adjustment, without interfering with wine sensory quality.
- Effect of ion exchange resins on white and red wine pH: impact on wine sensory characteristicsPublication . Borges, Rita; Fernandes, Conceição; Marques, Celeste; Matos, Carlos; Vilela, Alice; Filipe-Ribeiro, Luis; Nunes, Fernando M.; Cosme, FernandaThe pH control during winemaking is a fundamental parameter by their influence on color, freshness and to achieve wine microbiological stability. The most common acidify correction performed in wineries is addition of natural tartaric acid; however, in some cases, this operation increases the risks of potassium bitartrate precipitations [1, 2]. The application of ion exchange resins for wine acidification is based on ability of exchanging ions fixed on functional groups, namely by exchanging cations, such as potassium, with hydrogen ions. Nevertheless, there is an important lack of knowledge on the impact of this operation on wine sensory characteristics. To adjust wine pH, a certain amount of treated wine by ion exchange resins is mixed with the untreated wine [3]. According to OIV [4], treatment must not lower the pH of wine below 3.0 and the decrease should not exceed 0.3 pH units. Anion exchangers are not allowed by the OIV [3] due to the negative effects on the wine sensory quality [5,6]. Therefore, the aim of this work was to evaluate the effect of cation exchange resins, authorized by the OIV, according to Resolution 43/2000 [3] on wine pH control and to evaluate their impact on wine sensory quality at industrial scale. In this study a white and a red wine from the Douro Valley region, 2015 vintage, was used. In this work ion exchange resin treated white wine was almost 20% from total white wine volume and red wine was almost 30% from total red wine volume. The present study indicated that there were no considerable changes in sensory attributes, although a slight improvement in the aroma and taste, as a result of the ion-exchange pH adjustment. These results show that the application of ion exchange resins process to wine could be an interesting tool for white and red wine pH adjustment, without interfering with wine sensorial quality.
- Impact of ion exchange resin treatment on red wine sensory profile, phenolic and mineral compositionPublication . Borges, Rita; Marques, Celeste; Vilela, Alice; Nunes, Fernando M.; Cosme, Fernanda; Fernandes, ConceiçãoIon exchange resins presented a polymeric matrix with covalently attached ionized functional groups, electrically neutralized by movable ions of opposite electrical charge present in the wine. Cationic resins in acid cycle are the only authorized by the International Organisation of Vine and Wine for wine treatment, according to the Resolution 43/2000 [1] for wine treatment. However, in order to get an equilibrated wine the wine treated by ion exchange resin must be mixed with a percentage of untreated wine. In this study was used a red wine from the Douro Valley and a pH-Stab/AEB laboratory ion exchange resin. The aim of this work was to evaluate the impact of ion exchange resins on red wine phenolic composition, mineral composition, chromatic and sensory characteristics. The experiment was carried out at Gran Cruz Winery and the percentage of treated red wine was 30% (total of 1000L). Conventional oenological parameters were determined using a FTIR Baccus, chromatic characteristics were determined using the Cielab method according to OIV [2], total phenols, flavonoids and non-flavonoids were determined according Kramling and Singleton [3] and the phenolic profile was determined by HPLC according to Guise et al [4]. Finally, sensory analysis was performed by a trained panel of 7 members and fifteen attributes - visual (limpidity, colour), aroma (aroma intensity, fruity, floral, vegetable, oxidised, chemist) and taste (sweetness, acidity, bitterness, flavour intensity, body, balance, persistence) - assessed using a ten-point intensity scale (ISO 4121, 2003). Red wine treated with ion exchange resins, presented lower concentration of phenolic compounds compared to untreated one. Calcium, magnesium and potassium decrease in wines treated with ion exchange resin (Table 1). Regarding sensory characteristics, wine treated with ion exchange resins seems to improve some sensory attributes, namely aroma and taste.
- Impact of ion exchange resins comparing to oenological additives on wine qualityPublication . Borges, Rita; Fernandes, Conceição; Vilela, Rita; Marques, Celeste; Vilela, Alice; Matos, Carlos; Nunes, Fernando M.; Cosme, FernandaTartaric acid is the most important organic acid in the wine. It is easily ionized, leading to the formation of precipitates like potassium hydrogen tartrate (KHT) and calcium tartrate (CaT). Although, not harmful to health of the consumer, these precipitates, leads to a decrease in the commercial acceptance and consequently to the decrease of the commercial value of the wine. To prevent the occurrence of these precipitations several treatments can be used. Among them, ion exchange resins is an accepted stabilization process by the OIV according to the Resolution 43/2000, as well as the treatment with oenological products such as metatartaric acid, since 1970, and carboxymetilcelulose (CMC’s), since 2009. Therefore, the aim of this work was to compare the impact of ion exchange resins with oenological additives, such as CMC’s with different structural features and metatartaric acid, on wine quality. For this propose, Douro Valley wines treated with ion exchange resins, CMC and metatartaric acid were evaluated concerning there physicochemical (phenolic compounds, chromatic characteristics, mineral composition and phenolic profile by HPLC-DAD) and sensory characteristics. Results shown that, white wine treated with ion exchange resins, presented lower concentration of total phenolic compounds compared to treated wines with oenological additives. Also, phenolic profile obtained by chromatographic analysis showed differences among treatments. Regarding white wine sensory characteristics, ion exchange resins seem to improve some sensory attributes, namely colour intensity, in these treated wines. Similarly, red wines aroma and taste were also improved, when treated with ion exchange resins (Figure 1). These data suggest that wines treated with ion exchange resins, maintained or improved wine quality. This work was partially funded by the Chemical Research Centre (CQ-UTAD). Additional thanks to AEB Bioquímica Portuguesa and to the Projet I&D INNOVINE&WINE – Vineyard and Wine Innovation Platform, NORTE-01-0145-FEDER-000038, co-financed by the Fundo Europeu de Desenvolvimento Regional (FEDER) through the NORTE 2020 (Programa Operacional Regional do Norte 2014/2020).
- Impact of ion exchange resins comparing to oenological additives on wine qualityPublication . Borges, Rita; Fernandes, Conceição; Veiga, Rita; Marques, Celeste; Vilela, Alice; Matos, Carlos; Nunes, Fernando M.; Cosme, FernandaTartaric acid is easily ionized, leading to the formation of precipitates like potassium hydrogen tartrate (KHT) and calcium tartrate (CaT CaT). Although, not harmful to consumer health, these precipitates leads to a decrease in the commercial commercial value of the wine. To prevent the occurrence of these precipitations precipitations several treatments can be used.