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R J Beamish - One of the best experts on this subject based on the ideXlab platform.

R Scott J Lacombe - One of the best experts on this subject based on the ideXlab platform.

  • natural abundance Carbon Isotope Ratio analysis and its application in the study of diet and metabolism
    Nutrition Reviews, 2020
    Co-Authors: R Scott J Lacombe, Richard P Bazinet
    Abstract:

    Due to differences in Carbon assimilation pathways between plants, there are subtle but distinct variations in the Carbon Isotope Ratios of foods and animal products throughout the food supply. Although it is well understood that the Carbon Isotope Ratio composition of the diet influences that of the consumers' tissues, the application of natural abundance Carbon Isotope Ratio analysis in nutrition has long been underappreciated. Over the past decade, however, several studies have investigated the utility of Carbon Isotope Ratio analysis for evaluation of nutritional biomarker status, primarily focusing on its application as an objective indicator of sugar and animal protein intake. More recently, research investigating the application of natural abundance measurements has been extended to study fatty acid metabolism and has yielded encouraging results. Collectively, data from large-scale observational studies and experimental animal studies highlight the potential for Carbon Isotope Ratio analysis as an additional and effective tool to study diet and metabolism. The purpose of this review is to provide an overview of natural abundance Carbon Isotope Ratio analysis, its application to studying nutrition, and an update of the research in the field.

  • turnover of brain dha in mice is accurately determined by tracer free natural abundance Carbon Isotope Ratio analysis
    Journal of Lipid Research, 2020
    Co-Authors: R Scott J Lacombe, Chichiu Lee, Richard P Bazinet
    Abstract:

    The brain is highly enriched in the long-chain omega-3 (n-3) PUFA DHA. Due to the limited capacity for local DHA synthesis in the brain, it relies on a continual supply from the circulation to replenish metabolized DHA. Previous studies investigating brain DHA turnover and metabolism have relied on Isotope tracers to determine brain fatty acid kinetics; however, this approach is cumbersome and costly. We applied natural abundance Carbon Isotope Ratio analysis via high-precision gas chromatography combustion Isotope Ratio mass spectrometry, without the use of labeled tracers, to determine the half-life of brain DHA in mice following a dietary switch experiment. Mice fed diets containing either α-linolenic acid (ALA) or DHA as the sole dietary n-3 PUFA were switched onto diets containing ALA, DHA, or ALA + DHA at 6 weeks of age, while control mice were maintained on their respective background diet. We measured brain DHA Carbon Isotope Ratios (reported as δ13CDHA signatures) over a 168-day time course. Brain δ13CDHA signatures of control mice maintained on background diets over the time course were stable (P > 0.05). Brain δ13CDHA signatures of mice switched to the DHA or ALA + DHA diet from the ALA diet changed over time, yielding brain incorpoRation half-lives of 40 and 34 days, respectively. These half-lives determined by natural abundance Carbon Isotope Ratio analysis were consistent with estimates from kinetic Isotope tracer studies. Our results demonstrate the feasibility of natural abundance Carbon Isotope Ratio analysis in the study of fatty acid metabolism without the use of isotopically labeled fatty acid tracers.

Richard P Bazinet - One of the best experts on this subject based on the ideXlab platform.

  • natural abundance Carbon Isotope Ratio analysis and its application in the study of diet and metabolism
    Nutrition Reviews, 2020
    Co-Authors: R Scott J Lacombe, Richard P Bazinet
    Abstract:

    Due to differences in Carbon assimilation pathways between plants, there are subtle but distinct variations in the Carbon Isotope Ratios of foods and animal products throughout the food supply. Although it is well understood that the Carbon Isotope Ratio composition of the diet influences that of the consumers' tissues, the application of natural abundance Carbon Isotope Ratio analysis in nutrition has long been underappreciated. Over the past decade, however, several studies have investigated the utility of Carbon Isotope Ratio analysis for evaluation of nutritional biomarker status, primarily focusing on its application as an objective indicator of sugar and animal protein intake. More recently, research investigating the application of natural abundance measurements has been extended to study fatty acid metabolism and has yielded encouraging results. Collectively, data from large-scale observational studies and experimental animal studies highlight the potential for Carbon Isotope Ratio analysis as an additional and effective tool to study diet and metabolism. The purpose of this review is to provide an overview of natural abundance Carbon Isotope Ratio analysis, its application to studying nutrition, and an update of the research in the field.

  • turnover of brain dha in mice is accurately determined by tracer free natural abundance Carbon Isotope Ratio analysis
    Journal of Lipid Research, 2020
    Co-Authors: R Scott J Lacombe, Chichiu Lee, Richard P Bazinet
    Abstract:

    The brain is highly enriched in the long-chain omega-3 (n-3) PUFA DHA. Due to the limited capacity for local DHA synthesis in the brain, it relies on a continual supply from the circulation to replenish metabolized DHA. Previous studies investigating brain DHA turnover and metabolism have relied on Isotope tracers to determine brain fatty acid kinetics; however, this approach is cumbersome and costly. We applied natural abundance Carbon Isotope Ratio analysis via high-precision gas chromatography combustion Isotope Ratio mass spectrometry, without the use of labeled tracers, to determine the half-life of brain DHA in mice following a dietary switch experiment. Mice fed diets containing either α-linolenic acid (ALA) or DHA as the sole dietary n-3 PUFA were switched onto diets containing ALA, DHA, or ALA + DHA at 6 weeks of age, while control mice were maintained on their respective background diet. We measured brain DHA Carbon Isotope Ratios (reported as δ13CDHA signatures) over a 168-day time course. Brain δ13CDHA signatures of control mice maintained on background diets over the time course were stable (P > 0.05). Brain δ13CDHA signatures of mice switched to the DHA or ALA + DHA diet from the ALA diet changed over time, yielding brain incorpoRation half-lives of 40 and 34 days, respectively. These half-lives determined by natural abundance Carbon Isotope Ratio analysis were consistent with estimates from kinetic Isotope tracer studies. Our results demonstrate the feasibility of natural abundance Carbon Isotope Ratio analysis in the study of fatty acid metabolism without the use of isotopically labeled fatty acid tracers.

Selim Biyik - One of the best experts on this subject based on the ideXlab platform.

  • detection of adulterated honey produced by honeybee apis mellifera l colonies fed with different levels of commercial industrial sugar c and c plants syrups by the Carbon Isotope Ratio analysis
    Food Chemistry, 2014
    Co-Authors: Ahmet Umut Guler, Hasan Kocaokutgen, Ali Vaiz Garipoglu, Hasan Onder, Deniz Ekinci, Selim Biyik
    Abstract:

    In the present study, one hundred pure and adulterated honey samples obtained from feeding honeybee colonies with different levels (5, 20 and 100 L/colony) of various commercial sugar syrups including High Fructose Corn Syrup 85 (HFCS-85), High Fructose Corn Syrup 55 (HFCS-55), Bee Feeding Syrup (BFS), Glucose Monohydrate Sugar (GMS) and Sucrose Sugar (SS) were evaluated in terms of the δ(13)C value of honey and its protein, difference between the δ(13)C value of protein and honey (Δδ(13)C), and C4% sugar Ratio. Sugar type, sugar level and the sugar type*sugar level interaction were found to be significant (P<0.001) regarding the evaluated characteristics. AdulteRations could not be detected in the 5L/colony syrup level of all sugar types when the δ(13)C value of honey, Δδ(13)C (protein-honey), and C4% sugar Ratio were used as criteria according to the AOAC standards. However, it was possible to detect the adulteRation by using the same criteria in the honeys taken from the 20 and 100 L/colony of HFCS-85 and the 100L/colony of HFCS-55. AdulteRation at low syrup level (20 L/colony) was more easily detected when the fructose content of HFCS syrup increased. As a result, the official methods (AOAC, 978.17, 1995; AOAC, 991.41, 1995; AOAC 998.12, 2005) and Internal Standard Carbon Isotope Ratio Analysis could not efficiently detect the indirect adulteRation of honey obtained by feeding the bee colonies with the syrups produced from C3 plants such as sugar beet (Beta vulgaris) and wheat (Triticium vulgare). For this reason, it is strongly needed to develop novel methods and standards that can detect the presence and the level of indirect adulteRations.

  • detection of adulterated honey produced by honeybee apis mellifera l colonies fed with different levels of commercial industrial sugar c3 and c4 plants syrups by the Carbon Isotope Ratio analysis
    Food Chemistry, 2014
    Co-Authors: Ahmet Umut Guler, Hasan Kocaokutgen, Ali Vaiz Garipoglu, Hasan Onder, Deniz Ekinci, Selim Biyik
    Abstract:

    Abstract In the present study, one hundred pure and adulterated honey samples obtained from feeding honeybee colonies with different levels (5, 20 and 100 L/colony) of various commercial sugar syrups including High Fructose Corn Syrup 85 (HFCS-85), High Fructose Corn Syrup 55 (HFCS-55), Bee Feeding Syrup (BFS), Glucose Monohydrate Sugar (GMS) and Sucrose Sugar (SS) were evaluated in terms of the δ 13 C value of honey and its protein, difference between the δ 13 C value of protein and honey (Δδ 13 C), and C 4 % sugar Ratio. Sugar type, sugar level and the sugar type * sugar level interaction were found to be significant ( P 13 C value of honey, Δδ 13 C (protein–honey), and C 4 % sugar Ratio were used as criteria according to the AOAC standards. However, it was possible to detect the adulteRation by using the same criteria in the honeys taken from the 20 and 100 L/colony of HFCS-85 and the 100 L/colony of HFCS-55. AdulteRation at low syrup level (20 L/colony) was more easily detected when the fructose content of HFCS syrup increased. As a result, the official methods (AOAC, 978.17, 1995; AOAC, 991.41, 1995; AOAC 998.12, 2005) and Internal Standard Carbon Isotope Ratio Analysis could not efficiently detect the indirect adulteRation of honey obtained by feeding the bee colonies with the syrups produced from C 3 plants such as sugar beet ( Beta vulgaris ) and wheat ( Triticium vulgare ). For this reason, it is strongly needed to develop novel methods and standards that can detect the presence and the level of indirect adulteRations.

Torsten C Schmidt - One of the best experts on this subject based on the ideXlab platform.

  • Carbon Isotope Ratio measurements of glyphosate and AMPA by liquid chromatography coupled to Isotope Ratio mass spectrometry
    Analytical and Bioanalytical Chemistry, 2013
    Co-Authors: Dorothea Kujawinski, J. Benjamin Wolbert, Lijun Zhang, Maik Jochmann, David Widory, Nicole Baran, Torsten C Schmidt
    Abstract:

    The interest in compound-specific Isotope analysis for product authenticity control and source differentiation in environmental sciences has grown rapidly during the last decade. However, the isotopic analysis of very polar analytes is a challenging task due to the lack of suitable chromatographic sepaRation techniques which can be used coupled to Isotope Ratio mass spectrometry. In this work, we present the first method to measure Carbon Isotope compositions of the widely applied herbicide glyphosate and its metabolite aminomethylphosphonic acid (AMPA) by liquid chromatography coupled to Isotope Ratio mass spectrometry. We demonstrate that this analysis can be carried out either in cation exchange or in reversed-phase sepaRation modes. The reversed-phase sepaRation yields a better performance in terms of resolution compared with the cation exchange method. The measurement of commercial glyphosate herbicide samples show its principal applicability and reveals a wide range of δ^13C values between −24 and −34 ‰ for different manufacturers. The absolute minimum amounts required to perform a precise and accurate determination of Carbon Isotope compositions of glyphosate and AMPA were in the sub-microgram range. The method proposed is sensitive enough to further perform the experiments that are necessary to better understand the Carbon Isotope fractionation associated to the natural degradation of glyphosate into AMPA. Furthermore, it can be used for contaminant source allocation and product authenticity as well.

  • flow injection analysis Isotope Ratio mass spectrometry for bulk Carbon stable Isotope analysis of alcoholic beverages
    Journal of Agricultural and Food Chemistry, 2009
    Co-Authors: Maik Jochmann, Dirk Steinmann, Manuel Stephan, Torsten C Schmidt
    Abstract:

    A new method for bulk Carbon Isotope Ratio determination of water-soluble samples is presented that is based on flow injection analysis−Isotope Ratio mass spectrometry (FIA-IRMS) using an LC IsoLink interface. Advantages of the method are that (i) only very small amounts of sample are required (2−5 μL of the sample for up to 200 possible injections), (ii) it avoids complex sample prepaRation procedures such as needed for EA-IRMS analysis (only sample dilution and injection,) and (iii) high throughput due to short analysis times is possible (∼15 min for five replicates). The method was first tested and evaluated as a fast screening method with industrially produced ethanol samples, and additionally the applicability was tested by the measurement of 81 alcoholic beverages, for example, whiskey, brandy, vodka, tequila, and others. The minimal sample concentRation required for precise and reproducible measurements was around 50 μL L−1 ethanol/water (1.71 mM Carbon). The limit of repeatability was determined t...