β-Carotene Absorption and Metabolism
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| Language: | English |
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The Ohio State University / OhioLINK
2011
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| Online Access: | http://rave.ohiolink.edu/etdc/view?acc_num=osu1313548706 |
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ndltd-OhioLink-oai-etd.ohiolink.edu-osu1313548706 |
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NDLTD |
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English |
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Analytical Chemistry Biochemistry Food Science Nutrition &946 -Carotene bioaccessibility apocarotenoids &946 -carotene absorption and metabolism BCO1 BCO2 |
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Analytical Chemistry Biochemistry Food Science Nutrition &946 -Carotene bioaccessibility apocarotenoids &946 -carotene absorption and metabolism BCO1 BCO2 Fleshman, Matthew Kintz β-Carotene Absorption and Metabolism |
| author |
Fleshman, Matthew Kintz |
| author_facet |
Fleshman, Matthew Kintz |
| author_sort |
Fleshman, Matthew Kintz |
| title |
β-Carotene Absorption and Metabolism |
| title_short |
β-Carotene Absorption and Metabolism |
| title_full |
β-Carotene Absorption and Metabolism |
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β-Carotene Absorption and Metabolism |
| title_full_unstemmed |
β-Carotene Absorption and Metabolism |
| title_sort |
β-carotene absorption and metabolism |
| publisher |
The Ohio State University / OhioLINK |
| publishDate |
2011 |
| url |
http://rave.ohiolink.edu/etdc/view?acc_num=osu1313548706 |
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AT fleshmanmatthewkintz bcaroteneabsorptionandmetabolism |
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1719430192869408768 |
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ndltd-OhioLink-oai-etd.ohiolink.edu-osu13135487062021-08-03T06:03:33Z β-Carotene Absorption and Metabolism Fleshman, Matthew Kintz Analytical Chemistry Biochemistry Food Science Nutrition &946 -Carotene bioaccessibility apocarotenoids &946 -carotene absorption and metabolism BCO1 BCO2 <p>β-Carotene is the most potent provitamin A carotenoid and has potential antioxidant properties. A better understanding of bioaccessibility, absorption, and metabolism of β-carotene may help alleviate symptoms and diseases related to vitamin A deficiency. To better understand β-carotene absorption, we have studied β-carotene in fruits and vegetables, its bioaccessibility from food sources through in vitro digestion, and absorption by humans in a controlled feeding study. We also studied the metabolism of β-carotene by measuring the presence of β-apocarotenoids in foods, mice, and humans, as well as the conversion of newly absorbed β-carotene to its retinoid metabolites. </p><p>The first study was conducted to determine the β-carotene content and its bioaccessibility/bioavailability in orange-fleshed melons. Orangedew melons have less consumer risk for food borne illness and have significantly more β-carotene than cantaloupes grown under the same conditions. Micellerization of β-carotene during simulated digestion of orange-fleshed melons was approximately 3.2%. We also detected and quantified β-apocarotenoids in the melons. </p><p>The second study was conducted to investigate in humans the variability in β-carotene absorption and its conversion to vitamin A and to compare the efficiency of absorption of β-carotene with that of cholesterol. Ten men consumed a 5 mg dose of deuterium labeled β-carotene (d8-βC), with 6 subjects repeating the dose 2 months later. For this study, we developed a method that provides a simple sample extraction for both retinoids and β-carotene that included minimal sample handling, and allows us to detect and quantify newly absorbed d8-β-carotene, as well as its d4-retinyl ester metabolites. The method allowed us to accurately measure d8-β-carotene absorption, and its extent of conversion to d4-retinyl esters. There was marked inter-individual variability in β-carotene absorption and conversion to retinyl-esters. In contrast, intra-individual variability in β-carotene absorption and its conversion to retinyl esters was low. β-Carotene and cholesterol may share specific intestinal transporters, but there was no correlation between an individual’s efficiency of absorption of β-carotene and his efficiency of absorption of cholesterol (r=-0.09; p=0.81). </p><p>The third study was conducted to determine the β-apocarotenoid levels in commonly consumed products containing β-carotene, such as fruits and vegetables, as well as in murine serum and liver, and human plasma. β-Apocarotenoids are present in our diets but their absorption, metabolism, and biological roles are largely unknown. Using HPLC-MS, we were able to detect and quantify β-apo-13-carotenone, β-apo-14’-carotenal, β-apo-12’-carotenal, β-apo-10’-carotenal, β-apo-8’-carotenal and β-carotene in several fruits and vegetables. In vitro digestion studies have shown that β-apocarotenoids are micellerized to a greater extent than β-carotene. We have shown here that they are present in considerable amounts in the diet and that they may be absorbed in addition to being generated in vivo. We have also shown that these β-apocarotenoids are present in the liver and serum of β-carotene fed mice and in human plasma. We have uncovered new aspects of β-carotene absorption and metabolism that should be considered in future β-carotene studies, such as conversion of β-carotene to specific retinyl esters, low intra-individual variability of β-carotene absorption, and the presence of β-apocarotenoids in all β-carotene containing samples.</p> 2011-09-26 English text The Ohio State University / OhioLINK http://rave.ohiolink.edu/etdc/view?acc_num=osu1313548706 http://rave.ohiolink.edu/etdc/view?acc_num=osu1313548706 unrestricted This thesis or dissertation is protected by copyright: all rights reserved. It may not be copied or redistributed beyond the terms of applicable copyright laws. |