Research Topics
| Michael RychlikSummaryCountry: Germany Publications
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Publications
Comparison of folate quantification in foods by high-performance liquid chromatography-fluorescence detection to that by stable isotope dilution assays using high-performance liquid chromatography-tandem mass spectrometryAchim Freisleben
, , Lichtenbergstrasse 4, D-85748 Garching, Germany
Anal Biochem 315:247-55. 2003....
Quantification of the mycotoxins patulin and ochratoxin A by stable isotope dilution assaysM Rychlik
Technical University Munich, Lichtenbergstr 4, 85748, Garching, Germany
Mycotoxin Res 21:263-9. 2005..In contrast to PAT, OTA was detectable in human blood and urine samples. Under the assumption that the majority of OTA is circulating in blood, an urinary excretion rate of about 1% of the whole body content per day was calculated...- Quantification of free coumarin and its liberation from glucosylated precursors by stable isotope dilution assays based on liquid chromatography-tandem mass spectrometric detectionMichael Rychlik
Lehrstuhl fur Lebensmittelchemie der Technischen Universitat Munchen, Lichtenbergstrasse 4, D 85748 Garching, Germany
J Agric Food Chem 56:796-801. 2008..In Ceylon cinnamon and cassia, the odorant occurred mainly in its free form, whereas in fenugreek seeds and woodruff, 68 and 88% of the total coumarin content was liberated from glucosylated precursors, respectively... - Pantothenic acid quantification: method comparison of a stable isotope dilution assay and a microbiological assayMichael Rychlik
Lehrstuhl fur Lebensmittelchemie der Technischen Universitat Munchen, Lichtenbergstr 4, D 85748 Garching, Germany
Int J Vitam Nutr Res 75:218-23. 2005..Furthermore, the data imply that microbial enzymes were able to cleave PA conjugates more effectively than pantetheinase and phosphatase treatment... - Quantitation of N2-[1-(1-carboxy)ethyl]folic acid, a nonenzymatic glycation product of folic acid, in fortified foods and model cookies by a Stable isotope dilution assayMichael Rychlik
Lehrstuhl fur Lebensmittelchemie der Technischen Universitat Munchen, Garching, Germany
J Agric Food Chem 53:5116-24. 2005..Therefore, CEF can be considered an important degradation product of FA in baked foods made from fructose. To retain a maximum amount of FA, products should rather be baked with sucrose than with reducing carbohydrates... - Absorption of the mycotoxin patulin from the rat stomachMichael Rychlik
Institute for Food Chemistry, Technical University Munich, Lichtenbergstr 4, 85748 Garching, Germany
Food Chem Toxicol 42:729-35. 2004..Thus our results show that even low concentrations of patulin penetrate the gastric wall. Toxic effects, however, are unlikely as most of the patulin is disintegrated... - Rapid degradation of the mycotoxin patulin in man quantified by stable isotope dilution assaysMichael Rychlik
Institut für Lebensmittelchemie der Technischen, Universitat Munchen, Lichtenbergstr 4 D 85748, Garching, Germany
Food Addit Contam 20:829-37. 2003..1% of the mycotoxin was detected after 2 min. It was concluded, therefore, that even high naturally occurring concentrations of patulin in foods are quickly degraded before reaching other tissues than the gastrointestinal tract... - Stable isotope dilution assays in mycotoxin analysisMichael Rychlik
Lehrstuhl für Lebensmittelchemie der Technischen, Universitat Munchen, Lichtenbergstr 4, 85748, Garching, Germany
Anal Bioanal Chem 390:617-28. 2008..As the commercial availability of these compounds continues to increase, SIDAs can be expected to find expanding use in mycotoxin analysis... - Pantothenic acid quantification by a stable isotope dilution assay based on liquid chromatography-tandem mass spectrometryMichael Rychlik
Institut für Lebensmittelchemie der Technischen Universität München, Lichtenbergstr 4, D 85748 Garching, Germany
Analyst 128:832-7. 2003.... - Application of stable isotope dilution assays based on liquid chromatography-tandem mass spectrometry for the assessment of folate bioavailabilityMichael Rychlik
Institut für Lebensmittelchemie der Technischen Universität München, Lichtenbergstrasse 4, D 85748 Garching, Germany
J Chromatogr B Analyt Technol Biomed Life Sci 792:167-76. 2003..The relative bioavailability of folate following meal A exceeded significantly the suggested value of 50% for food folates by taking the dose-normalized area under the curve (AUC) following ingestion of meal B as reference... - Synthesis of four carbon-13-labeled type a trichothecene mycotoxins and their application as internal standards in stable isotope dilution assaysStefan Asam
, Lichtenbergstrasse 4, D-85748 Garching, Germany
J Agric Food Chem 54:6535-46. 2006..Diacetoxyscirpenol was detected on potatoes, whereas monoacetoxyscirpenol was not present in the analyzed samples... - Concentrations of total glutathione and cysteine in wheat flour as affected by sulfur deficiency and correlation to quality parametersJulia Reinbold
Deutsche Forschungsanstalt fur Lebensmittelchemie, Lichtenbergstrasse 4, D 85748 Garching, Germany
J Agric Food Chem 56:6844-50. 2008..Thus, the low concentration of GSH and Cys in flour from S-deficient wheat had a similar effect on the technological properties as the altered composition of gluten proteins... - Specific and sensitive quantification of folate vitamers in foods by stable isotope dilution assays using high-performance liquid chromatography-tandem mass spectrometryAchim Freisleben
, , Lichtenbergstrasse 4, 85748 Garching, Germany
Anal Bioanal Chem 376:149-56. 2003..Using the new method, folate contents were determined in meat, cereals, and vegetables. Data were in good agreement with literature data, except results for broccoli, which were much lower than reported in previous studies... - Quantification of 1,8-cineole and of its metabolites in humans using stable isotope dilution assaysKathie Horst
Lehrstuhl fur Lebensmittelchemie, Technische Universitat Munchen, Garching, Germany
Mol Nutr Food Res 54:1515-29. 2010..Summing up the urinary excretion over 10 h, 2-hydroxycineole, the 9-isomer, the 3-isomer and the 7-isomer accounted for 20.9, 17.2, 10.6 and 3.8% of the cineole dose, respectively... - Stable isotope dilution assays of alternariol and alternariol monomethyl ether in beveragesStefan Asam
Technische Universitat Munchen, Lehrstuhl fur Lebensmittelchemie, Garching, Germany
J Agric Food Chem 57:5152-60. 2009..However, the developed SIDA has proven to be optimally suited for further studies on alternariol and alternariol methyl ether content in food samples to obtain further insight into possible health hazards for the consumer... - Quantitation of folates and their catabolites in blood plasma, erythrocytes, and urine by stable isotope dilution assaysSabine Mönch
Lehrstuhl fur Lebensmittelchemie, Technische Universitat Munchen, Garching, Germany
Anal Biochem 398:150-60. 2010..The sum of folate catabolites increased by a factor of 2 in the urine of the latter volunteer, compared with that resulting when only water was dosed... - Effects of processing and of storage on the stability of pantothenic acid in sea buckthorn products (Hippophaë rhamnoides L. ssp. rhamnoides) assessed by stable isotope dilution assayDerek Gutzeit
Central Institute of the Bundeswehr Medical Service Munich, Ingolstädter Landstrasse 102, 85748 Garching, Hochbrück, Germany
J Agric Food Chem 55:3978-84. 2007..The processing effects of juice production and subsequent concentration revealed a decrease of about 6-7% in the juice and of 23% in the juice concentrate... - Quantification of ochratoxin A in foods by a stable isotope dilution assay using high-performance liquid chromatography-tandem mass spectrometryMichael Lindenmeier
, Lichtenbergstr. 4, D-85748 Garching, Germany
J Chromatogr A 1023:57-66. 2004..However, three samples of raisins exceeded the legal limit of 10 microg/kg and highlighted the need for further controlling the contamination with the mycotoxin... - Changes of folates, dietary fiber, and proteins in wheat as affected by germinationPeter Koehler
Deutsche Forschungsanstalt fur Lebensmittelchemie, Hans Dieter Belitz Institut für Mehl und Eiweissforschung, and Lehrstuhl für Lebensmittelchemie der Technischen Universität München, Lichtenbergstrasse 4, D 85748 Garching, Germany
J Agric Food Chem 55:4678-83. 2007..Prolonged germination times of up to 168 h led to a substantial increase of total dietary fiber and to a strong increase of the soluble dietary fiber by a factor of 3, whereas the insoluble fiber decreased by 50%... - Syntheses of labeled vitamers of folic acid to be used as internal standards in stable isotope dilution assaysAchim Freisleben
, Lichtenbergstrasse 4, D-85748 Garching, Germany
J Agric Food Chem 50:4760-8. 2002..The mass spectrometric studies confirmed that the compounds could be used as internal standards in stable isotope dilution assays... - Study of the metabolism of estragole in humans consuming fennel teaAnnette Zeller
Lehrstuhl fur Lebensmittelchemie der Technischen Universitat Munchen, Lichtenbergstrasse 4, D 85748 Garching, Germany
Chem Res Toxicol 22:1929-37. 2009..The presence of a sulfuric acid conjugate of estragole could not be confirmed, possibly due to its high reactivity and lability... - Folate content in sea buckthorn berries and related products (Hippophaë rhamnoides L. ssp. rhamnoides): LC-MS/MS determination of folate vitamer stability influenced by processing and storage assessed by stable isotope dilution assayDerek Gutzeit
Central Institute of the Bundeswehr Medical Service Munich, Garching Hochbrück, Germany
Anal Bioanal Chem 391:211-9. 2008..The juice showed almost identical degradation of 5-methyltetrahydrofolate of about 17-20% at 25 degrees C and 40 degrees C after 7 days of storage. [figure: see text].. - Use of isotope-labeled aflatoxins for LC-MS/MS stable isotope dilution analysis of foodsChristian Cervino
Institute of Hydrochemistry, Technische Universitat Munchen, Munchen, Germany
J Agric Food Chem 56:1873-9. 2008..The method was successfully applied to determine trace levels of aflatoxins in diverse food matrices such as peanuts, nuts, grains, and spices. Aflatoxin contents in these samples ranged from about 0.5 to 6 microg/kg... - Pantothenate synthetase is essential but not limiting for pantothenate biosynthesis in ArabidopsisRafal Jonczyk
Lehrstuhl fur Genetik, Technische Universitat Munchen, Am Hochanger 8, 85350 Freising, Germany
Plant Mol Biol 66:1-14. 2008..The data indicate that the pantothenate and CoA contents follow distinct developmental programs and that both transcriptional and posttranslational control mechanisms are important for CoA homeostasis... - A 90-day safety study in Wistar rats fed genetically modified rice expressing snowdrop lectin Galanthus nivalis (GNA)Morten Poulsen
Department of Toxicology and Risk Assessment, Danish Institute for Food and Veterinary Research, Mørkhøj Bygade 19, DK 2860 Søborg, Denmark
Food Chem Toxicol 45:350-63. 2007.... - A 90-day safety study of genetically modified rice expressing Cry1Ab protein (Bacillus thuringiensis toxin) in Wistar ratsMalene Schrøder
Department of Toxicology and Risk Assessment, Danish Institute for Food and Veterinary Research, Mørkhøj Bygade 19, DK 2860 Søborg, Denmark
Food Chem Toxicol 45:339-49. 2007..Nevertheless the experiences from this study lead to the overall conclusion that safety assessment for unintended effects of a GM crop cannot be done without additional test group(s)... - Safety testing of GM-rice expressing PHA-E lectin using a new animal test designMorten Poulsen
Department of Toxicology and Risk Assessment, Danish Institute for Food and Veterinary Research, Mørkhøj Bygade 19, DK 2860 Søborg, Denmark
Food Chem Toxicol 45:364-77. 2007..The spiking procedure has facilitated the interpretation of the results of the study and transferred it into a valuable tool for the future safety testing of genetically modified foods...