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| Registros recuperados: 29 | |
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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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| 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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| 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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| 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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| Husted, Søren; Persson, D.P.; Laursen, K.H.; Hansen, T.H.; Pedas, P.; Schiller, M.; Hegelund, J.N.; Schjørring, J.K.. |
| Inductively coupled plasma-mass spectrometry (ICP-MS) is the state-of-the-art technique for multi-elemental analysis of plant tissue. It provides a powerful tool in functional genomics, linking altered elemental profiles of mutants with gene expression and function. In addition, with its unmatched sensitivity, ICP-MS enables characterization of the substrate specificity and regulation of membrane transport proteins. Digestion of plant tissue has traditionally represented a bottleneck due to the low capacity of commercially available equipment. However, recent developments in micro-scaled digestion, combined with semi-quantitative analysis and chemometrics, have enabled high-throughput multi-elemental profiling and multivariate classification of large... |
| Tipo: Journal paper |
Palavras-chave: Food systems; Knowledge management. |
| Ano: 2011 |
URL: http://orgprints.org/19089/1/Review.pdf |
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| 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 |
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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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| 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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| 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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| Registros recuperados: 29 | |
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