168 research outputs found

    As propriedades ecofisiológicas, químicas e sensoriais de folhas provenientes de plantas de erva-mate com e sem frutificação.

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    Com o objetivo de determinar as propriedades fisiológicas, químicas e sensoriais das plantas de erva-mate no período de frutificação, marcou-se quatro pares de plantas femininas e masculinas. Na época de frutificação das plantas femininas mediu-se: regime radiativo destas plantas (PPFD em µmol fótons.m-2.s-1), condutância estomática (CS em mol.m-2.s-1), fotossíntese liquida (Pn em CO2.m-2.s-1), conteúdo de N, P, Ca, K, Mg (g/kg) nas folhas de posições diferenciadas na copa (dentro e periferia da parte inferior do terço médio da copa e no terço superior - ponteiras). Das folhas de plantas masculinas e femininas, depois de sapeco, secagem e extração de solúveis de erva-mate, realizou-se a análise sensorial de intensidade de sabor amargo. As folhas de plantas femininas apresentaram maior Pn que as de plantas masculinas, ao nível inferior do terço médio da copa, tanto dentro, quanto fora dele. Somente as folhas nas ponteiras, expostas à radiação não limitada, não se diferenciaram para as plantas entre os dois sexos. A quantidade de nitrogênio das folhas no nível inferior do terço médio da copa das plantas femininas foi maior e mais uniforme entre os indivíduos, enquanto nas folhas de ponteiras foi relativamente menor. Maior Pn de folhas nas plantas femininas deu-se através de maior CS e maior conteúdo de N (proteínas foliares). O sabor amargo pode estar interrelacionado com conteúdo maior de Mg.Secão: Manejo e Conservação. Feira do Agronegócio da Erva-mate, 1., 2003, Chapecó. Integrar para promover o agronegócio da erva-mate

    Intensity of bitterness of processed yerba mate leaves originated in two contrasted light environments.

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    The bitterness intensity of beverage prepared from the leaves produced on the males and females of yerba mate (Ilex paraguariensis), grown in the forest understory and monoculture, was evaluated. The leaves were grouped by their position (in the crown and on the branch tips) and by the leaf age. The leaf gas exchange, leaf temperature and photosynthetic photon flux density were observed. Inter and intra-specific competition for light and self-shading showed the same effect on yerba mate beverage taste. All the shading types resulted in bitterer taste of the processed yerba mate leaves compared to the leaves originated under the direct sun exposure. The leaves from the plants grown in the monoculture showed less bitterness than those grown in the forest understory. This conclusion was completely opposite to the conventionally accepted paradigm of the yerba mate industries. The leaves from the tips (younger leaves) of the plants grown in the monoculture resulted a beverage of softer taste; the males produced less bitter leaves in any light environment (forest understory or in the crown in monoculture). The taste was related to the photosynthetic and transpiration rate, and leaf temperature. Stronger bitterness of the leaves provided from the shade conditions was related to the decreased leaf temperature and transpiration in the diurnal scale

    Quality of yerba-mate leaves originating from male and female plants.

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    Qualidade das folhas de erva-mate oriundas de plantas masculinas e femininas: Este estudo teve por objetivo avaliar o sabor da bebida preparada a partir de folhas de erva-mate, de plantas masculinas e femininas. As propriedades ecofisiológicas, químicas e sensoriais foram avaliadas em uma das fases de brotação e em duas fases de frutificação. As plantas masculinas e femininas não diferiram em produção de matéria fresca e seca, nem nos teores de macro-e-micro-elementos. Mas, as plantas femininas apresentaram maior fotossíntese líquida (A) e condutância estomática (gs). A bebida preparada com folhas oriundas de plantas masculinas foi menos amarga do que das femininas, particularmente quando coletadas das ponteiras dos ramos. A intensidade de amargor apresentou correlação positiva com o teor de Zn e Mg nas plantas femininas e com gs e teor de Mn nas plantas masculinas. O amargor da bebida preparada de plantas masculinas mostrou-se negativamente correlacionada com teor de K. A masculinização de erval pode ser uma solução para se produzir erva-mate de sabor normal a suave

    Propriedades ecofisiológicas e produtivas com ferramenta para melhoramento genético de erva-mate (Ilex paraguariensis St. Hill.).

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    O trabalho teve por objetivos estimar parâmetros genéticos para 59 progênies de meios-irmãos de erva-mate, por ocasião da poda de formação, bem como avaliar propriedades ecofisiológicas para quatro progênies (P15, P18, P41 e P47) e duas testemunhas (P61 e P62) componentes de um teste combinado de procedências e progênies em Erechim, RS. As propriedades ecofisiológicas (condutância estomática (gs) – mol m-2s-1, fotossíntese liquida (A) - ?mol CO2 m- 2s-1 e transpiração (E) –mmol H2O m-2s-1) foram medidas durante um ano (de setembro de 2002 a agosto de 2003) em cinco épocas. Os componentes de variâncias, parâmetros genéticos e fenotípicos e valores genéticos (para dados de massa foliar coletados em poda de formação) foram obtidos através do programa genético - estatístico “SELEGEN – REML/BLUP”. A análise de parâmetros ecofisiológicos mostrou a sazonalidade de respostas, tornando-a importante na avaliação. A sazonalidade de troca gasosa acompanha a ocorrência de paradas e ondas de crescimento da erva-mate. As progênies P18 e P47, classificadas quanto ao valor genético, em quinto e 23o lugar, respectivamente, apresentaram maior A, maior economia de água (menor E com maior A) e maior sobrevivência, quando comparadas com P15 e P41, que ocuparam a 23a e a 40a posição, respectivamente. Com herdabilidade individual no sentido restrito de 22,7%, é necessário recorrer a métodos de seleção que utilizem, simultaneamente, as informações do indivíduo e da média de sua família, para melhorar o peso de massa foliar em planta de erva-mate. Houve coerência entre respostas genéticas na análise de massa foliar e análise ecofisiológica, o que sugere avaliar componentes ecofisiológicos acompanhando a avaliação de massa foliar ou/e massa total, no processo de seleção e melhoramento genético da erva-mate

    Recovery of pectinases from Aspergillus niger using aqueous two-phase systems / Recuperação de pectinases de Aspergillus niger usando sistemas aquosos bifásicos

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    This work aimed to study the purification of pectinases by aqueous two-phase systems (ATPS). The crude enzymatic extract was produced by Aspergillus niger ATCC 9642 and contained exo-polygalacturonase (exo-PG), pectinmethylesterase (PME) and pectin lyase (PMGL). The ATPS systems tested consisted in the combinations of polyethylene glycol (PEG) and potassium phosphate and sodium citrate, alcohol (ethanol, n-propanol and isopropanol) and salt (ammonium sulfate, potassium phosphate and sodium citrate). The experiments showed higher recoveries using ATPS system - PEG/phosphate for the exo-PG were using 16% PEG 4.0 kDa/4.8% NaCl and 16% PEG 1.5 kDa/without NaCl, obtaining purification factors (PF) of 1.37 and 1.21 times and recovery (R) of 49 and 59%, respectively. However, for the enzymes PME and PMGL were of 4.8 and 4.7 fold and 478 and 241%, respectively. When used ATPS system - PEG/sodium citrate the best PF were of 2.4, 7.85 and 5.7 and R of 100, 331 and 239% for exo-PG, PME and PMGL, respectively. The ATPS system is an alternative and efficient method for the recovery and/or purification of pectinases. This work aimed to study the purification of pectinases by aqueous two-phase systems (ATPS). The crude enzymatic extract was produced by Aspergillus niger ATCC 9642 and contained exo-polygalacturonase (exo-PG), pectinmethylesterase (PME) and pectin lyase (PMGL). The ATPS systems tested consisted in the combinations of polyethylene glycol (PEG) and potassium phosphate and sodium citrate, alcohol (ethanol, n-propanol and isopropanol) and salt (ammonium sulfate, potassium phosphate and sodium citrate). The experiments showed higher recoveries using ATPS system - PEG/phosphate for the exo-PG were using 16% PEG 4.0 kDa/4.8% NaCl and 16% PEG 1.5 kDa/without NaCl, obtaining purification factors (PF) of 1.37 and 1.21 times and recovery (R) of 49 and 59%, respectively. However, for the enzymes PME and PMGL were of 4.8 and 4.7 fold and 478 and 241%, respectively. When used ATPS system - PEG/sodium citrate the best PF were of 2.4, 7.85 and 5.7 and R of 100, 331 and 239% for exo-PG, PME and PMGL, respectively. The ATPS system is an alternative and efficient method for the recovery and/or purification of pectinases. This work aimed to study the purification of pectinases by aqueous two-phase systems (ATPS). The crude enzymatic extract was produced by Aspergillus niger ATCC 9642 and contained exo-polygalacturonase (exo-PG), pectinmethylesterase (PME) and pectin lyase (PMGL). The ATPS systems tested consisted in the combinations of polyethylene glycol (PEG) and potassium phosphate and sodium citrate, alcohol (ethanol, n-propanol and isopropanol) and salt (ammonium sulfate, potassium phosphate and sodium citrate). The experiments showed higher recoveries using ATPS system - PEG/phosphate for the exo-PG were using 16% PEG 4.0 kDa/4.8% NaCl and 16% PEG 1.5 kDa/without NaCl, obtaining purification factors (PF) of 1.37 and 1.21 times and recovery (R) of 49 and 59%, respectively. However, for the enzymes PME and PMGL were of 4.8 and 4.7 fold and 478 and 241%, respectively. When used ATPS system - PEG/sodium citrate the best PF were of 2.4, 7.85 and 5.7 and R of 100, 331 and 239% for exo-PG, PME and PMGL, respectively. The ATPS system is an alternative and efficient method for the recovery and/or purification of pectinases

    Leaching of carbon from native and non-native leaf litter of subtropical riparian forests

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    We evaluated the leaching of dissolved organic and inorganic carbon (DOC and DIC, respectively) from leaf litter of plant species of the native Atlantic Forest and of Pinus elliottii (Engelm.) and Eucalyptus grandis (Hill ex Maiden) forests. We carried out experiments in which leaves from each forest system (native, E. grandis, and P. elliottii) were placed in reactors with sterile water. After 1/4 h, 1 h, 4 h, 12 h, 24 h, and 48 h of incubation, we quantified the concentrations of DIC and DOC of each leachate. The greatest quantity of DIC was leached in the native forest system, whereas the greatest quantity of DOC was leached in the E. grandis forest system. With respect to the period of year, the greatest quantity of DIC was leached in autumn, whereas that of DOC was leached in the summer. Our results demonstrated that the replacement of native species in riparian zones, by non-native forest monocultures, could alter the chemical composition of the water. Finally, the results presented in this paper reinforce the need for a more careful look at ecological processes

    Properties of tofu coagulated with Cardoon flower (Cynara Cardunculus L.)

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    Tofu was elaborated using water-soluble extract of soybean grains from the cultivar BRS 267 with cardoon flower (C. Cardunculus L.), as coagulant as an alternative to the traditional coagulant magnesium chloride. The tofu were evaluated in relation to physical, chemical, microbiological and sensory properties during 14 days. Was obsersed for the tofu coagulated with cardoon flower that the moisture, pH, total mineral, protein, and syneresis decreased with the storage, while Kunitz Trypsin Inhibitor, ureatic activity and phytic acid did not change. It was also obtained a positive effect for color (L*, a*) parameters, phytic acid, yield, syneresis, and acceptance. The textural properties, showed a tendency to increase of hardness and stickiness, while springiness and cohesiveness decreased during storage. Structurally, presented irregular-shaped, small pores or cavities. The sensory analysis, showed has great acceptance and purchase intent. Then, the cardoon flower can be used as vegetal coagulant improving the quality properties of tofu, in relation to magnesium chloride. Keywords: Texture; Acceptance; Vegetable coagulante; Storage. O tofu foi elaborado usando extrato hidrossolúvel dos grãos de soja da cultivar BRS 267, utilizando a flor do cardo (C. Cardunculus L.), como coagulante alternativo ao processo tradicional com cloreto de magnésio. O tofu foi avaliado em relação as propriedades físicas, químicas, microbiológicas e sensoriais durante 14 dias. Foi observado para o tofu coagulado com a flor do cardo que a umidade, o pH, o mineral total, a proteína e a sinérese diminuíram com o armazenamento, enquanto o Inibidor de Tripsina de Kunitz, a atividade ureática e o ácido fítico não se alteraram. Foi também observado um efeito positivo para os parâmetros de cor (L *, a *), ácido fítico, rendimento, sinérese e aceitação. As propriedades texturais mostraram uma tendência de aumentar a dureza e a gomosidade, Research, Society and Development, v. 10, n. 16, e207101623576, 2021 (CC BY 4.0) | ISSN 2525-3409 | DOI: http://dx.doi.org/10.33448/rsd-v10i16.23576 2 enquanto a elasticidade e a coesividade diminuíram durante o armazenamento. Estruturalmente, apresentou pequenos poros ou cavidades irregulares. A análise sensorial mostrou grande aceitação e intenção de compra. Então, a flor do cardo pode ser utilizada como coagulante vegetal melhorando as propriedades de qualidade do tofu, em relação ao cloreto de magnésio. Palavras-chave: Textura; Aceitação; Coagulante vegetal; Estocage

    Gastronomy and Wine in the Alentejo Portuguese Region: Motivation and Satisfaction of Turists from Évora

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    Food and winemaking are a recognized tangible and intangible culturalheritage of Portugal. From the relationshipbetween these twocomponents, astrategic product emerged with a considerable potential for tourism industry, which is notignored bymany of tourism organizations. This chapter intends to analyze food and winemaking from atourism demand perspective. Particularly, this study describes visitors’ profi le, including, their motivations, their knowledgeabout theenological and gastronomicresourcesand the degreeof satisfaction. A total of 308 questionnaires were collected between February and May of 2012, from the visitors that visited the historic center of Évora (Alentejo-Portugal). Results reveal a visitor profi le associated with regional cuisine and wine products from Portugal. Moreover, visitors’ evidenced a high level of knowledge regarding the Portuguese cuisine and regional wines; although this not matches with their primary motivation for visit the city of Évora
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