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| Registros recuperados: 29 | |
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| 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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| 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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| 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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| 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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| Kapolna, Emese; Hillestrøm, Peter; Laursen, Kristian; Husted, Søren; Larsen, Erik H.. |
| Carrot (Daucus carota) shoots were enriched by selenium using foliar application. Solutions of sodium selenite or sodium selenate at 10 and 100 lg Se ml�1, were sprayed on the carrot leaves and the selenium content and uptake rate of selenium were estimated by ICP–MS analysis. Anion and cation exchange HPLC were tailored to and applied for the separation of selenium species in proteolytic extracts of the biological tissues using detection by ICP–MS or ESI–MS/MS. Foliar application of solutions of selenite or selenate at 100 lg Se ml�1 resulted in a selenium concentration of up to 2 lg Se g�1 (dry mass) in the carrot root whereas the selenium concentration in the controls was below the limit of detection at 0.045 lg Se g�1 (dry mass).... |
| Tipo: Journal paper |
Palavras-chave: Farming Systems; Food systems. |
| Ano: 2009 |
URL: http://orgprints.org/19083/4/19083.pdf |
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| 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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| Husted, Søren. |
| In AuthenticFood a wide range of analytical methods have been developed and validated for authentication of organic plant products. These have been applied to plant samples from Danish and Italian field trials and independent test-set samples. It has been shown that several analytical methods have the potential to authenticate the geographical and/or the agricultural origin of plant products. Elemental fingerprint analysis is particularly suitable for revealing where a plant has been grown due to the inherently different soil mineralogy of geographical locations across Europe. When zooming in on individual elements by stable isotope analysis it is also possible to reveal how a plant has been fertilized – especially when focusing on isotopes of specific... |
| Tipo: Report |
Palavras-chave: "Organics" in general Farming Systems Soil Values; Standards and certification Food systems. |
| Ano: 2015 |
URL: http://orgprints.org/29372/7/29372.pdf |
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| 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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| 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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| 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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| Registros recuperados: 29 | |
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