109 research outputs found

    Identificação e caracterização nutricional de blends de farinha

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    Neste estudo efetuou-se uma caracterização nutricional de três blends de farinha de trigo mole (com a designação “Bolachas”, “Corrente” e “Melhorador”), fornecidos pelo Instituto Nacional de Investigação Agrária e Veterinária (Pólo de Elvas). Efetuaram-se análises físicas e químicas dos blends em grão e nas respetivas farinhas (peso e volume de mil grãos, densidade, cor, humidade, elementos minerais, cinzas, lípidos, ácidos gordos, açúcares solúveis, proteína, índice de queda e sedimentação SDS, glúten, farinografia e alveografia). Considerando a totalidade das análises efetuadas foi possível verificar que as características nutricionais estão diretamente relacionadas com os objetivos a que estes blends se destinam (produção de bolachas, pão ou correção de características).info:eu-repo/semantics/publishedVersio

    Identificação e caracterização do perfil nutricional de sêmolas contrastantes

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    Neste estudo assumiu-se como objetivo a caracterização de sêmolas contrastantes, no âmbito de um projeto para conclusão da Licenciatura em Bioquímica, na Faculdade de Ciências e Tecnologias da Universidade Nova de Lisboa. A nível académico este projeto teve como objetivos principais o aprofundar de conhecimentos ao nível da produção agroindustrial, e ainda uma concretização prática de conhecimentos adquiridos durante a Licenciatura em Bioquímica, que atualmente se encontra em fase de conclusão. Foi também um objetivo, a perceção de como alguns procedimentos laboratoriais, anteriormente objeto de aprendizagem, podem ser utilizados na análise e caracterização de produtos da indústria alimentar, mais concretamente, na caracterização a nível nutricional de sêmolas contrastantes. Em 4 tipo de amostras de trigo duro (variedades Hélvio, Preto Amarelo, TE 1202 e Celta), cedidas pela Estação Nacional de Melhoramento de Plantas de Elvas – Instituto Nacional de Investigação Agrária e Veterinária, efetuou-se a caracterização do peso, volume e de densidade dos grãos. Nas respetivas sêmolas efetuou-se uma caracterização de micro e macronutrientes, assim como os índices de cor, e teores de humidade, cinzas, proteínas, ácidos gordos, glúten, açúcares. Concluiu-se que nas quatro variedades de trigo duro a maioria dos parâmetros está dentro dos parâmetros legislados.info:eu-repo/semantics/publishedVersio

    Influência da iluminação LED no desempenho fotossintético e na produtividade de Fragaria x ananassa em substrato

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    I Congresso Luso-Brasileiro de Horticultura. Sessão Horticultura Herbácea (Olericultura)Durante o crescimento e desenvolvimento das plantas, fatores ambientais como a radiação solar e a temperatura podem ser limitantes no período outono-inverno quando a intensidade luminosa e a temperatura são mais baixas, afetando a atividade fotossintética e a produtividade. Um acréscimo de luz, através do uso de lâmpadas LED (light-emitting diodes), pode minimizar os impactos negativos para a fisiologia da planta em condições menos favoráveis de luminosidade, nomeadamente em zonas temperadas (dias curtos). São poucos os estudos efetuados para avaliar a influência do fator luz no comportamento do morangueiro em termos de eficiência fotossíntetica e nos diferentes componentes da produção, nas condições ambientais portuguesas. Neste sentido, foram avaliados alguns parâmetros fisiológicos e a produtividade de oito cultivares de morangueiro (‘Albión’, ‘Camarosa’, ‘Liberty’, ‘Merced’, ‘Rabida’, ‘Reliance’, ‘San Andreas’ e ‘Splendor’) sujeitas a dois tratamentos de luz (com e sem lâmpadas LED) e conduzidas em dois tipos de substrato [fibra de coco (Coco) e mistura de casca de pinheiro compostada, turfa e fibra de coco (M1)]. O ensaio decorreu no complexo de estufas do INIAV, I.P., em Oeiras e a programação da luz foi diária com início em novembro até ao final de fevereiro. O comportamento fisiológico das plantas foi avaliado em duas fases: floração e plena frutificação. Durante a floração, na maioria dos casos, as plantas sujeitas à luz LED apresentaram maiores valores da taxa fotossintética líquida (Pn) e menores valores de transpiração (E) em relação ao controlo. Este efeito variou entre cultivares e substrato. Na fase de plena frutificação (já sem o tratamento de luz), os valores de Pn foram mais baixos, com diferenças entre cultivares e modalidades de substrato. O teor de clorofilas (SPAD) variou apenas em função da cultivar (p <0,05), nas duas fases de avaliação. Um suplemento de luz durante o outono não influenciou a produtividade das cultivares. A produtividade das plantas conduzidas em substrato Coco foi, em média, 23% superior à das plantas em substrato M1. A maior produtividade ocorreu nas cvs. Rabida, Camarosa e San Andreas. Estes resultados sugerem que o desempenho fotossintético e a produtividade da Fragaria ×ananassa estão mais dependentes do genótipo e do substrato do que da luz adicional. Contudo, um suplemento de luz em condições limitantes de radiação pode contribuir para um melhor desempenho fotossintético das plantas de morangueiroinfo:eu-repo/semantics/publishedVersio

    Phenotypic Diversity of Seminal Root Traits in Bread Wheat Germplasm from Different Origins

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    Publisher Copyright: © 2022 by the authors.Bread wheat (Triticum aestivum L.) is a major staple crop, and more adapted varieties are needed to ensure productivity under unpredictable stress scenarios resulting from climate changes. In the development of new genotypes, root system traits are essential since roots have a key function in water and nutrient uptake, and root architecture determines the plant’s ability to spatially explore the soil resources. Genetic variation in wheat root system may be assessed at the early stages of development. This study evaluates in vitro and at the seedling stage, the genetic diversity of root growth angle (RGA), seminal root number (SRN), and radicle length (RadL) in 30 bread wheat genotypes from different origins and belonging to distinct evolutive or breeding groups. SRN and RadL were analyzed at 1, 2, 3 and 6 days after sowing (DAS) and RGA was measured through the angle between the first pair of seminal roots. A large variability was found in RGA values that ranged from 63° to 122°. Although differences were found between genotypes within the same groups, the narrower angles tended to occur among landraces, while the higher RGA values were observed in advanced lines and Australian varieties. Differences were also observed as regards the SRN (1.0–3.0, 2.7–4.7, 3.2–5.0 and 4.4–6.3 at 1, 2, 3 and 6 DAS, respectively) and RadL (0.1–1.5, 2.1–5.0, 4.0–7.5 and 5.1–13.7 cm at 1, 2, 3 and 6 DAS, respectively). Genetic variability in root traits at seedling stage allows more rapid selection of genotypes better adapted to environmental and soil constraints, necessary to Portuguese Wheat Breeding Program. It will also contribute to the definition of wheat ideotypes with improved performance under Mediterranean climate conditions.publishersversionpublishe

    Unveiling the Impact of Growth Traits on the Yield of Bread Wheat Germplasm Subjected to Waterlogging

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    Publisher Copyright: © 2024 by the authors.Changes in the climate have led to the occurrence of extreme events that threaten the production of major crops, namely that of bread wheat (Triticum aestivum L.). Waterlogging imposed at the tillering stage can severely affect the yield, but several genotype features may counterbalance the negative impacts on yields. The aim of this work was to evaluate the effect of waterlogging on the number of fertile spikes, kernels per plant, and single kernel weight, as well as to assess the main culm and tiller participation in yields. We also investigated if the growth stages affected by stress would influence such traits. The study was conducted in climatized growth chambers using 23 genotypes from five distinct germplasm groups (Portuguese landraces, varieties with the introduced Italian germplasm, post-Green Revolution varieties with the introduced CIMMYT germplasm, advanced lines from the Portuguese wheat breeding program, Australian varieties). Variability was observed between and within the groups. Ten genotypes performed well under waterlogged conditions, showing promising results. Among these, GR-2 showed a rise in tiller yield, AdvL-3 in both the main culm and tiller yield, and the remaining ones displayed unaltered values in both the main culm and tillers. PL-1, PL-5, GR-1, GR-3, AdvL-2, Austrl-2, and Austrl-4 were able to compensate for the decreases observed for several traits, reaching harvest yield values that were unaffected in both the main culm and tillers. Rises in the tiller yield or in the tillers and main culm, GR-2 and AdvL-3 exhibited either stability or increases in all the studied parameters. Results also suggest a negative correlation between the growth stage reached during waterlogging and the effect of this stress on the number of spikes per plant, plant and tiller yield, kernel per spike (tillers), and single kernel weight (tillers). Our findings may contribute to a better understanding of wheat responses to waterlogging and to the development of solutions that mitigate the socio-economic impacts of 20–50% wheat yield reductions, thereby preserving the daily 20% supply of energy and protein required for human nutrition and global food security.publishersversionpublishe

    Grain Composition and Quality in Portuguese Triticum aestivum Germplasm Subjected to Heat Stress after Anthesis

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    Funding Information: Funding: This work was supported by national funds from Fundação para a Ciência e a Tecnologia (FCT), Portugal, through the Research Unit UIDP/04035/2020 (GeoBioTec). Funding Information: This work was supported by national funds from Funda??o para a Ci?ncia e a Tecnologia (FCT), Portugal, through the Research Unit UIDP/04035/2020 (GeoBioTec).The authors acknowledge GeoBioTec (UIDB/04035/2020) Research Center for support facilities. Publisher Copyright: © 2022 by the authors. Licensee MDPI, Basel, Switzerland.Bread wheat (Triticum aestivum) is a major crop worldwide, and it is highly susceptible to heat. In this work, grain production and composition were evaluated in Portuguese T. aestivum germplasm (landraces and commercial varieties), which was subjected to heat after anthesis (grain filling stage). Heat increased the test weight (TW) in Nabão, Grécia and Restauração, indicating an improved flour-yield potential. Mocho de Espiga Branca (MEB) and Transmontano (T94) showed higher thousand-kernel weight (TKW). Gentil Rosso presented increased soluble sugars, which are yeast substrates in the bread-making process. Ardila stood out for its protein increase under heat. Overall SDS was unaffected by higher temperature, but increased in T94, indicating a better dough elasticity for bread-making purposes. Under heat, lipid content was maintained in most genotypes, being endogenous fatty acids (FAs) key players in fresh bread quality. Lipid unsaturation, evaluated through the double bond index (DBI), also remained unaffected in most genotypes, suggesting a lower flour susceptibility to lipoperoxidation. In Grécia, heat promoted a higher abundance of monounsaturated oleic (C18:1) and polyunsaturated linoleic (C18:2) acids, which are essential fatty acids in the human diet. This work highlighted a great variability in most parameters both under control conditions or in response to heat during grain filling. Cluster analysis of traits revealed a lower susceptibility to heat during grain filling in Ardila, Restauração, and Ruivo, in contrast to MEQ, which seems to be more differentially affected at this stage. Characterization and identification of more favorable features under adverse environments may be relevant for agronomic, industrial, or breeding purposes, in view of a better crop adaptation to changing climate and an improved crop sustainability in agricultural systems more prone to heat stress.publishersversionpublishe

    Will Casuarina glauca Stress Resilience Be Maintained in the Face of Climate Change?

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    Actinorhizal plants have been regarded as promising species in the current climate change context due to their high tolerance to a multitude of abiotic stresses. While combined salt-heat stress effects have been studied in crop species, their impact on the model actinorhizal plant, Casuarina glauca, has not yet been fully addressed. The effect of single salt (400 mM NaCl) and heat (control at 26/22 C, supra optimal temperatures at 35/22 C and 45/22 C day/night) conditions on C. glauca branchlets was characterised at the physiological level, and stress-induced metabolite changes were characterised by mass spectrometry-based metabolomics. C. glauca could withstand single salt and heat conditions. However, the harshest stress condition (400 mM NaCl, 45 C) revealed photosynthetic impairments due to mesophyll and membrane permeability limitations as well as major stress-specific differential responses in C and N metabolism. The increased activity of enzymatic ROS scavengers was, however, revealed to be sufficient to control the plant oxidative status. Although C. glauca could tolerate single salt and heat stresses, their negative interaction enhanced the effects of salt stress. Results demonstrated that C. glauca responses to combined salt-heat stress could be explained as a sum of the responses from each single applied stressinfo:eu-repo/semantics/publishedVersio

    Mitigation of the Negative Impact of Warming on the Coffee Crop: The Role of Increased Air [CO2] and Management Strategies

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    Crop sustainability can be threatened by new environmental challenges regarding predicted climate changes and global warming. Therefore, the study of real biological impacts of future environmental conditions (e.g., increased air [CO2], supra-optimal temperature and water scarcity) on crop plants, as well as the re-evaluation of management procedures and strategies, must be undertaken in order to improve crop adaptation and promote mitigation of negative environmental impacts, thus affording crop resilience. Coffee is a tropical crop that is grown in more than 80 countries, making it one of the world’s most traded agricultural products, while involving millions of people worldwide in the whole chain of value. It has been argued that this crop will be highly affected by climate changes, resulting in decreases in both suitable areas for cultivation and productivity, as well as impaired beverage quality in the near future. Here, we report recent findings regarding coffee species exposure to combined supra-optimal air temperatures and enhanced air [CO2], and impacts of drought stress on the crop. Ultimately, we discuss key strategies to improve coffee performance in the context of new environmental scenarios. The recent findings clearly show that high [CO2] has a positive impact on coffee plants, increasing their tolerance to high temperatures. This has been related to a better plant vigor, to the triggering of protective mechanisms, and to a higher functional status of the photosynthetic machinery. Even so, coffee plant is expected to suffer from water scarcity in a changing world. Therefore, discussion is focused on some important management strategies (e.g., shade systems, crop management and soil covering and terracing), which can be implemented to improve coffee performance and sustain coffee production in a continually changing environment

    Implications on Mineral Elements, Sugars and Fatty Acids Accumulation in Tissues

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    Funding Information: This work received funding from PDR2020-101-030734 and Fundação para a Ciência e a Tecnologia, I.P. (FCT), Portugal, through the research units UIDB/04035/2020 (GeoBioTec), UIDB/00239/2020 (CEF) and UID/FIS/04559/2020 (LIBPhys) from the FCT/MCTES/PIDDAC. This work was further supported by the grant of Fundação para a Ciência e Tecnologia (FCT) UI/BD/150718/2020. Publisher Copyright: © 2022 by the authors.Following an agronomic approach for the Ca enrichment of Rocha pears, this study aimed to assess the interactions between mineral nutrients in fruit tissues at harvest and after storage for 5 months and to characterize the implications on the profile of sugars and fatty acids (FA). A total of seven foliar sprays (with concentrations of 0.1–0.6 kg·ha−1 Ca(NO3)2 and 0.8–8 kg·ha−1 CaCl2) were applied to pear trees. After harvest, the fruits were stored for 5 months, in environmentally controlled chambers, and the mineral contents in five regions (on the equatorial section) of the fruits were assessed, while the sugar and FA content were quantified. For both dates, all foliar sprayed treatments, at different extends, increased Ca content in the center and near the epidermis of Rocha pear fruits and the levels of K, Mn, Fe, Zn and Cu also varied. At harvest, the Ca treatments did not affect the levels of sucrose, glucose, fructose and sorbitol and, after storage, their concentrations remained higher in Ca-treated fruits. Additionally, the tendency of the relative proportions of FA was C18:2 > C18:1 > C16:0 > C18:3 > C18:0 > chains inferior to 16 C ( C16:0 > C18:3 > C18:0 > C18:1 > chains inferior to 16 C (<16:0). It is concluded that the heterogeneous distribution of Ca in the tissues of Rocha pear fruits results from its absorption in the peel after Ca(NO3)2 and CaCl2 sprays and from the xylemic flux in the core prior to maturity. Additionally, the hydrolysis of complex polysaccharides affects the contents of simpler sugars during maturation, ripening and senescence, while storage decreases the amount of total fatty acids (TFA), but the double bond index (DBI) indicate that cell membrane fluidity remains unaffected.publishersversionpublishe

    Lipid profile adjustments may contribute to warming acclimation and to heat impact mitigation by elevated [CO2] in Coffea spp

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    This work was supported by European Union, Program Horizon 2020, call H2020-SFS-2016-2, action RIA, and Portuguese national funds from Fundacao para a Ciencia e a Tecnologia (project PTDC/ASP-AGR/31257/2017; Funding from CNPq (fellowships to E. Campostrini, F.L. Partelli, and F.M. DaMatta) is also acknowledged.An unexpected heat resilience, and the mitigation of heat impacts by elevated [CO2] were recently reported in Coffea spp. Plants must maintain membrane fluidity and integrity to cope with temperature changes, which requires an adequate lipid dynamics. This work provides the lipid profile (galactolipids, GL; phospholipids, PL; sulfolipids, SL) of chloroplast membranes, and the expression of a set of genes related to lipid metabolism in Coffea arabica L. (cv. Icatu and IPR108) and C. canephora cv. Conilon CL153, under elevated [CO2] (380 or 700 μL L−1), heat (25/20, 31/25, 37/30 and 42/34 °C, day/night) and their interaction. Major membrane lipids alterations, different among genotypes, included: A) responsiveness of total fatty acids (TFAs) synthesis to [CO2] (except IPR108) and heat (except CL153); stronger remodeling (unsaturation degree) in the 700-plants from 37/30 °C to 42/34 °C, coordinated at transcriptional level with the down-regulation of fatty acid desaturase FAD3 gene (C. arabica) and up-regulation of lipoxygenase genes LOX5A (CL153 and Icatu) and LOX5B (Icatu) at the highest temperature; B) quantitative and qualitative modifications in GL (monogalactosyldiacylglycerol, MGDG; digalactosyldiacylglycerol, DGDG), PL (phosphatidylcholine, PC; phosphatidylglycerol, PG), and SL (sulfoquinovosyldiacylglycerol, SQDG) classes, prompted by heat, elevated [CO2], and, especially, the interaction, in CL153 and Icatu. Overall membrane enrichment with MGDG and DGDG as a result of heat and [CO2] interaction in these genotypes, but at the highest temperature only in Icatu the high [CO2] maintained greater contents and unsaturation values of these GLs than in the 380-plants. C) Among PL classes, PG seems to play an active role in heat acclimation of C. arabica genotypes, increasing in 700-plants at 42/34 °C. Globally, Icatu often showed changes closer to those of heat tolerant cv. CL153 than to cv. IPR108. Overall, lipid profile adjustments in chloroplast membranes, from TFAs bulk until FA unsaturation within each class, are expected to contribute to long-term acclimation to climate changes in coffee plant.publishersversionpublishe
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