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Registros recuperados: 21
Primeira ... 12 ... Última
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Bio-fortification and isotopic labelling of Se metabolites in onions and carrots following foliar application of Se and 77Se Organic Eprints
Kapolna, Emese; Laursen, Kristian Holst; Husted, Søren; Larsen, Erik H..
The aims were to bio-fortify onions by foliar application of selenium (Se) and to intrinsically label bioactive Se-metabolites in onion and carrot by enriched, stable77Se for use in human physiological studies. Onion bulbs and leaves were enriched in Se by repeated foliar spraying of 10 or 100 μg Se mL-1 solutions of sodium selenite (Se(IV)) or sodium selenate (Se(VI)). ICP-MS analysis of onion leaves and bulbs showed that the Se concentration was enhanced by up to a factor of approximately 50 and 200 in bulbs and leaves, respectively. HPLC-ICP-MS analysis of proteolytic plant extracts showed that foliar application of Se(IV) gave rise to bio-synthesis of a higher fraction of the desired organic Se species and was better tolerated by the plants than...
Tipo: Journal paper Palavras-chave: Food security; Food quality and human health Crop health; Quality; Protection.
Ano: 2011 URL: http://orgprints.org/19812/1/FOODCHEM-D-11-03087R1.pdf
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Comparison of Polyacetylene Content in Organically and Conventionally Grown Carrots Using a Fast Ultrasonic Liquid Extraction Method Organic Eprints
Søltoft, Malene; Eriksen, M.R.; Träger, A.W.B.; Nielsen, J.; Laursen, Kristian Holst; Husted, Søren; Halekoh, Ulrich; Knuthsen, Pia.
A rapid and sensitive analytical method for quantification of polyacetylenes in carrot roots was developed. The traditional extraction method (stirring) was compared to a new ultrasonic liquid processor (ULP)-based methodology using high-performance liquid chromatography−ultraviolet (HPLC−UV) and mass spectrometry (MS) for identification and quantification of three polyacetylenes. ULP was superior because a significant reduction in extraction time and improved extraction efficiencies were obtained. After optimization, the ULP method showed good selectivity, precision [relative standard deviations (RSDs) of 2.3−3.6%], and recovery (93% of falcarindiol) of the polyacetylenes. The applicability of the method was documented by comparative analyses of carrots...
Tipo: Journal paper Palavras-chave: Food systems.
Ano: 2010 URL: http://orgprints.org/19121/4/19121.pdf
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DEVELOPMENT OF MULTI-RESIDUE METHODS FOR PESTICIDE SCREENING IN ORGANIC FOOD SAMPLES Organic Eprints
Guignard, Cedric; Lenouvel, Audrey; Laursen, Kristian Holst; Husted, Søren.
There is an ever-increasing demand for foods of local origin or cultivated using organic practices. However, the sector is becoming dominated by corporate players that might not strictly fulfill all the requirements of organic farming, with or without fraud intentions. This places an increased burden on certification bodies and traceability systems on which the authenticity of the organic products depends. Thus, to ensure the authenticity of foods marketed and labelled as organic, there is a need for robust, accurate and validated control methods. The objective of the AuthenticFood project is to combine novel analytical techniques to improve the reliability of organic authentication. In this framework, the present work describes the development of...
Tipo: Conference paper, poster, etc. Palavras-chave: Food security; Food quality and human health.
Ano: 2015 URL: http://orgprints.org/29420/1/Poster_Euroanalysis2015_Guignard.pdf
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Discrimination of conventional and organic white cabbage from a long-term field trial study using untargeted LC-MS-based metabolomics Organic Eprints
Mie, Axel; Laursen, Kristian Holst; Aberg, K. Magnus; Forshed, Jenny; Lindahl, Anna; Thorup-Kristensen, Kristian; Olsson, Marie; Knuthsen, Pia; Larsen, Erik Huusfeldt; Husted, Søren.
The influence of organic and conventional farming practices on the content of single nutrients in plants is disputed in the scientific literature. Here, large-scale untargeted LC-MS-based metabolomics was used to compare the composition of white cabbage from organic and conventional agriculture, measuring 1,600 compounds. Cabbage was sampled in 2 years from one conventional and two organic farming systems in a rigidly controlled long-term field trial in Denmark. Using Orthogonal Projection to Latent Structures-Discriminant Analysis (OPLS-DA), we found that the production system leaves a significant (p = 0.013) imprint in the white cabbage metabolome that is retained between production years. We externally validated this finding by predicting the production...
Tipo: Journal paper Palavras-chave: Farming Systems Food security; Food quality and human health Crop health; Quality; Protection Farm nutrient management.
Ano: 2014 URL: http://orgprints.org/29054/1/Mie%202014%20Discrimination%20of%20conventional%20and%20organic%20white%20cabbage%20froma%20long-term%20field%20trial%20study%20using%20untargeted%20LC-MS-based%20metabolomics.pdf
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Discrimination of conventional and organic white cabbage from a long-term field trial study using untargeted LC-MS-based metabolomics Organic Eprints
Mie, Axel; Laursen, Kristian Holst; Aberg, K Magnus; Forshed, Jenny; Lindahl, Anna; Thorup-Kristensen, Kristian; Olsson, Marie; Knuthsen, Pia; Larsen, Erik Huusfeldt; Husted, Søren.
The influence of organic and conventional farming practices on the content of single nutrients in plants is disputed in the scientific literature. Here, large-scale untargeted LC-MS-based metabolomics was used to compare the composition of white cabbage from organic and conventional agriculture, measuring 1,600 compounds. Cabbage was sampled in 2 years from one conventional and two organic farming systems in a rigidly controlled long-term field trial in Denmark. Using Orthogonal Projection to Latent Structures-Discriminant Analysis (OPLS-DA), we found that the production system leaves a significant (p = 0.013) imprint in the white cabbage metabolome that is retained between production years. We externally validated this finding by predicting the production...
Tipo: Journal paper Palavras-chave: Farming Systems Food security; Food quality and human health Crop husbandry Crop health; Quality; Protection Farm nutrient management.
Ano: 2014 URL: http://orgprints.org/25578/1/Mie%202014%20Discrimination%20of%20conventional%20and%20organic%20white%20cabbage%20froma%20long-term%20field%20trial%20study%20using%20untargeted%20LC-MS-based%20metabolomics.pdf
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Dopingkontrol af økologiske planter med isotoper Organic Eprints
Laursen, Kristian Holst.
Dopingkontrol af økologiske planter med isotoper.
Tipo: Web product Palavras-chave: "Organics" in general Values; Standards and certification Food systems.
Ano: 2010 URL: http://orgprints.org/20033/1/20033.pdf
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Effects of Organic and Conventional Growth Systems on the Content of Flavonoids in Onions and Phenolic Acids in Carrots and Potatoes Organic Eprints
Søltoft, Malene; Nielsen, J.; Laursen, Kristian Holst; Husted, Søren; Halekoh, Ulrich; Knuthsen, Pia.
The demand for organic food products is steadily increasing partly due to the expected health benefits of organic food consumption. Polyphenols, such as flavonoids and phenolic acids, are a group of secondary plant metabolites with presumably beneficial health effects, and contents in plants are affected by, for example, plant nutrient availability, climate, pathogen infection, and pest attack. In the current study, onions, carrots, and potatoes were cultivated in two-year field trials in three different geographical locations, comprising one conventional and two organic agricultural systems. The contents of flavonoids and phenolic acids in plants were analyzed by pressurized liquid extraction and high-performance liquid chromatography−ultraviolet...
Tipo: Journal paper Palavras-chave: "Organics" in general; Food systems.
Ano: 2010 URL: http://orgprints.org/19119/4/19119.pdf
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Faglige nuancer efterlyses Organic Eprints
Husted, Søren; Laursen, Kristian Holst.
Faglige nuancer efterlyses
Tipo: Newspaper or magazine article Palavras-chave: Food systems; Knowledge management.
Ano: 2010 URL: http://orgprints.org/20027/3/20027.pdf
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Fingerprint analysis of biological samples using ICP-MS and IR-MS Organic Eprints
Laursen, Kristian Holst; Husted, Søren.
Atomic spectroscopy based analytical techniques can generate fingerprints encompassing the vast majority of elements found in the periodic table as well as ratios of their stable isotopes. These highly multivariate fingerprints have laid the foundation of many recent studies within environmental, geological, agricultural and food science. Inductively coupled plasma-optical emission spectroscopy (ICP-OES) and ICP-mass spectrometry (ICP-MS) still dominate multi-elemental analyses of biological samples while stable isotopes of the light mass elements H, C, N, O and S are measured by isotope ratio-mass spectrometry (IR-MS). However, it has recently been shown that rather unexplored analytical methods such as semi-quantitative ICP-MS and compound-specific...
Tipo: Conference paper, poster, etc. Palavras-chave: Education; Extension and communication.
Ano: 2012 URL: http://orgprints.org/23092/13/23092.pdf
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Micro-scaled high-throughput digestion of plant tissue samples for multi-elemental analysis Organic Eprints
Hansen, Thomas Hesselhøj; Laursen, Kristian Holst; Persson, Daniel Pergament; Pedas, Pai; Husted, Søren; Schjørring, Jan Kofod.
Quantitative multi-elemental analysis by inductively coupled plasma (ICP) spectrometry depends on a complete digestion of solid samples. However, fast and thorough sample digestion is a challenging analytical task which constitutes a bottleneck in modern multi-elemental analysis. Additional obstacles may be that sample quantities are limited and elemental concentrations low. In such cases, digestion in small volumes with minimum dilution and contamination is required in order to obtain high accuracy data. Results We have developed a micro-scaled microwave digestion procedure and optimized it for accurate elemental profiling of plant materials (1-20 mg dry weight). A commercially available 64-position rotor with 5 ml disposable glass vials, originally...
Tipo: Journal paper Palavras-chave: Food systems.
Ano: 2009 URL: http://orgprints.org/19087/4/19087.pdf
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Multielemental fingerprinting as a tool for authentication of organic wheat, barley, faba bean and potato Organic Eprints
Laursen, Kristian Holst; Schjoerring, Jan K.; Olesen, Jørgen E.; Askegaard, Margrethe; Halekoh, Ulrich; Husted, Søren.
The multielemental composition of organic and conventional winter wheat, spring barley, faba bean, and potato was analyzed with inductively coupled plasma−optical emission spectrometry (ICP-OES) and −mass spectrometry (ICP-MS). The crops were cultivated in two years at three geographically different field locations, each accommodating one conventional and two organic cropping systems. The conventional system produced the highest harvest yields for all crops except the nitrogen-fixing faba bean, whereas the dry matter content of each crop was similar across systems. No systematic differences between organic and conventional crops were found in the content of essential plant nutrients when statistically analyzed individually. However, chemometric analysis of...
Tipo: Journal paper Palavras-chave: "Organics" in general Farming Systems Soil Values; Standards and certification Food systems.
Ano: 2011 URL: http://orgprints.org/19091/4/19091.pdf
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Multi-elemental fingerprinting of plant tissue by semi-quantitative ICP-MS and chemometrics Organic Eprints
Laursen, Kristian Holst; Hansen, Thomas Hesselhøj; Persson, Daniel Pergament; Schjørring, Jan Kofod; Husted, Søren.
The multi-elemental capacity of Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) is rarely fully utilized in traditional full-quantitative analysis. The main obstacles are limited availability of multi-elemental standards and the need for time-consuming external calibrations. In this study, a novel semi-quantitative quadrupole ICP-MS based method for multi-elemental fingerprinting of plant tissue was developed as a high-throughput alternative to full-quantitative analysis. The main analytical objectives were low data acquisition time (<60 seconds), detailed coverage of the atomic mass range from 7Li to 238U and discrimination power similar to full-quantitative analysis based on chemometric data analysis. The method was tested on grains of different...
Tipo: Journal paper Palavras-chave: Values; Standards and certification Food systems.
Ano: 2009 URL: http://orgprints.org/19086/1/Laursen_2009.pdf
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Multi-elemental fingerprinting of plant tissue by semi-quantitative ICP-MS and chemometrics Organic Eprints
Laursen, Kristian Holst; Hansen, Thomas Hesselhøj; Persson, Daniel Pergament; Schjørring, Jan Kofod; Husted, Søren.
The multi-elemental capacity of Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) is rarely fully utilized in traditional full-quantitative analysis. The main obstacles are limited availability of multi-elemental standards and the need for time-consuming external calibrations. In this study, a novel semi-quantitative quadrupole ICP-MS based method for multi-elemental fingerprinting of plant tissue was developed as a high-throughput alternative to full-quantitative analysis. The main analytical objectives were low data acquisition time (<60 seconds), detailed coverage of the atomic mass range from 7Li to 238U and discrimination power similar to full-quantitative analysis based on chemometric data analysis. The method was tested on grains of different...
Tipo: Journal paper Palavras-chave: Values; Standards and certification Food systems.
Ano: 2009 URL: http://orgprints.org/19149/1/Laursen_2009.pdf
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Økologien sætter fingeraftryk Organic Eprints
Laursen, Kristian Holst; Husted, Søren.
Økologien sætter fingeraftryk
Tipo: Newspaper or magazine article Palavras-chave: Food systems; Knowledge management.
Ano: 2010 URL: http://orgprints.org/20032/3/20032.pdf
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OrgTrace – No Difference in Levels of Bioactive Compounds found in Crops from Selected Organic and Conventional Cultivation Systems Organic Eprints
Knuthsen, Pia; Soeltoft, Malene; Laursen, Kristian Holst; Bysted, Anette; Madsen, Katja H; Nielsen , John; Halekoh, Ulrich; Husted, Søren.
The objective of the present study was to compare the content of selected bioactive compounds in organically and conventionally grown crops, and to evaluate if the ability of the crops to synthesize selected secondary metabolites was systematically affected by growth systems across different growth years as well as soil types. The results showed that contents of neither polyacetylenes and carotenoids in carrots, flavonoids in onions, nor phenolic acids in carrots and potatoes were significantly influenced by growth system. Thus it could not be concluded that the organically grown crops had higher contents of bioactive compounds than the conventionally grown. This indicates that giving preference to organic products because they contain more bioactive...
Tipo: Conference paper, poster, etc. Palavras-chave: Food security; Food quality and human health.
Ano: 2011 URL: http://orgprints.org/19815/3/19815.pdf
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Overdreven tillid til jordbundsanalysen Organic Eprints
Husted, Søren; Yngvesson, J.P.A.; Laursen, Kristian Holst; Pedas, P..
Overdreven tillid til jordbundsanalysen
Tipo: Newspaper or magazine article Palavras-chave: Knowledge management.
Ano: 2008 URL: http://orgprints.org/19151/1/19151.pdf
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På sporet af det økologiske fingeraftryk Organic Eprints
Laursen, Kristian Holst.
På sporet af det økologiske fingeraftryk.
Tipo: Web product Palavras-chave: "Organics" in general Values; Standards and certification Food systems.
Ano: 2009 URL: http://orgprints.org/19155/1/19155.pdf
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På sporet af det økologiske fingeraftryk II Organic Eprints
Laursen, Kristian Holst.
På sporet af det økologiske fingeraftryk.
Tipo: Web product Palavras-chave: "Organics" in general Values; Standards and certification Food systems.
Ano: 2009 URL: http://orgprints.org/20023/1/20023.pdf
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Simultaneous iron, zinc, sulphur and phosphorus speciation analysis of barley grain tissues using SEC-ICP-MS and IP-ICP-MS Organic Eprints
Persson, Daniel Pergament; Hansen, Thomas Hesselhøj; Laursen, Kristian Holst; Schjørring, J.K.; Husted, Søren.
The increasing prevalence of iron (Fe) and zinc (Zn) deficiencies in human populations worldwide has stressed the need for more information about the distribution and chemical speciation of these elements in cereal products. In order to investigate these aspects, barley grains were fractionated into awns, embryo, bran and endosperm and analysed for Fe and Zn. Simultaneously, phosphorus (P) and sulfur (S) were determined since these elements are major constituents of phytic acid and proteins, respectively, compounds which are potentially involved in Fe and Zn binding. A novel analytical method was developed in which oxygen was added to the octopole reaction cell of the ICP-MS. This approach greatly improved the sensitivity of sulfur, measured as 48SO+....
Tipo: Journal paper Palavras-chave: Food systems.
Ano: 2009 URL: http://orgprints.org/19157/7/19157.pdf
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The OrgTrace project: Content, Bioavailability and Health Effects of Trace Elements and Bioactive Components of Food Products Cultivated in Organic and Conventional Agricultural Systems Organic Eprints
Husted, Søren; Laursen, Kristian Holst; Larsen, Erik Huusfeldt; Kapolna, Emese; Knuthsen, Pia; Søltoft, Malene; Bügel, Susanne; Mark, Alicja Budek; Lauridsen, Charlotte; Jacobsen, Maja; Jørgensen, Henry; Halekoh, Ulrich; Kristensen, Kristian.
Trace elements, bioactive secondary metabolites and vitamins are among the most important quality parameters in plants. Yet, very little information is available on their content, bioavailability and health effects in organically grown plant food products. The main objective of OrgTrace is to study the impact of different agricultural management practices relevant for organic farming on the ability of cereal and vegetable crops to absorb trace elements from the soil and to synthesize bioactive compounds (secondary metabolites, antioxidant vitamins and phytates) with health promoting effects. Based on different plant products produced in OrgTrace, diets were composed and the bioavailabilities of health promoting substances were analyzed in a human...
Tipo: Conference paper, poster, etc. Palavras-chave: "Organics" in general; Farming Systems; Soil; Food systems.
Ano: 2011 URL: http://orgprints.org/18877/4/18877.pdf
Registros recuperados: 21
Primeira ... 12 ... Última
 

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