Journal of chromatography. B, Analytical technologies in the biomedical and life sciences, 2015
High throughput GC-MS methods for quantification of alkylresorcinols (AR), biomarkers of whole gr... more High throughput GC-MS methods for quantification of alkylresorcinols (AR), biomarkers of whole grain wheat and rye intake, in plasma and adipose tissue and their metabolites in urine were developed and optimised. Alkylresorcinols in plasma (200μL) and adipose tissues (10-50mg) were extracted with diethyl ether, whereas main AR metabolites such as DHBA and DHPPA and newly identified metabolites in urine (50μL) were extracted with ethyl acetate after enzymatic deconjugation. All extracts were purified on OASIS-MAX solid phase extraction cartridges. Plasma and adipose tissue sample extracts were then derivatised with trifluoroacetic anhydride and reconstituted in undecane, whereas AR metabolites in urine samples were derivatised with BSTFA+TMCS (99:1, v/v, 100μL). Prepared samples were quantified by GC-MS (EI-SIM). Analysis of all compounds in the different matrices showed good selectivity, sensitivity, linearity, precision (<15% within and between batches), adequate recovery (75-10...
The effects of dietary (+)-catechin (CAT) and BHT on plasma and tissue concentrations of alpha-to... more The effects of dietary (+)-catechin (CAT) and BHT on plasma and tissue concentrations of alpha-tocopherol (alpha-T), gamma-tocopherol (gamma-T) and cholesterol (C) were studied in male Sprague-Dawley rats. The rats were fed the compounds during a 4-wk period at concentrations of 2 g/kg in standardized diets, low but adequate in vitamin E, with 2 g/kg cholesterol. The CAT-regimen did not affect weight gain, feed intake or organ weights. BHT did not affect feed intake but lowered the body weight and the amount of liver lipids and increased the weights of livers and lungs relative to the body weight. Rats consuming CAT had 2.5-3.5-fold increased plasma, liver and lung alpha-T concentrations, but C concentrations remained unchanged. BHT-feeding resulted in 2.4- and 1.7-fold elevation in alpha-T but approximately 50% decrease in gamma-T concentrations in blood plasma and liver, respectively. BHT also lowered total C in the liver without affecting the concentration of C in the liver lipid...
Background:-Tocopherol has unique properties that may be ben- eficial in sustaining optimal human... more Background:-Tocopherol has unique properties that may be ben- eficial in sustaining optimal human health, but hepatic vitamin E metabolism enhances -tocopherol turnover. Objective: Our aim was to determine the extent to which dietary sesame lignans alter human - and -tocopherol metabolism and elimination as carboxyethyl hydroxychromanols (CEHCs). Design: Healthy participants (n 5 women and 5 men) in a ran- domized, crossover study (with 4-wk washout) consumed muffins prepared with either corn oil or unrefined sesame oil (sesamin, 94 mg; sesamolin, 42 mg), along with a capsule containing a 1:1 molar ratio of deuterium-labeled d6-- and d2--tocopherol acetates (50 mgeach).Plasmaandurinewerecollectedupto72h;unlabeledand labeled tocopherol and CEHC concentrations were determined by liquid chromatography-mass spectrometry. Results:Sesame oil muffin consumption in men, but not in women, decreased(P0.05)areasunderplasmad2--CEHCconcentration-
Six groups of rats were fed diets low, but adequate, in α‐tocopherol but high in γ‐tocopherol. Th... more Six groups of rats were fed diets low, but adequate, in α‐tocopherol but high in γ‐tocopherol. The six diets differed only in their contents (0, 0.25, 0.5, 1.0, 2.0, and 4.0 g/kg, respectively) of sesamin, a lignan from sesame oil. After four weeks ofad libitum feeding, the rats were sacrificed and the concentrations of α‐ and γ‐tocopherols were measured in the plasma, livers, and lungs. Sesamin‐feeding increased γ‐tocopherol and γ‐/α‐tocopherol ratios in the plasma (P<0.05), liver (P<0.001), and lungs (P<0.001). The increase was non‐significant for α‐tocopherol. Thus, sesamin appears to spare γ‐tocopherol in rat plasma and tissues, and this effect persists in the presence of α‐tocopherol, a known competitor to γ‐tocopherol. This suggests that the bioavailability of γ‐tocopherol is enhanced in phenol‐containing diets as compared with purified diets.
This work shows that fucosterol, Δ5‐avenasterol, and similar ethylidene‐side chain sterols can un... more This work shows that fucosterol, Δ5‐avenasterol, and similar ethylidene‐side chain sterols can undergo acid‐catalyzed isomerization to give a mixture of five isomers. Four isomers formed from fucosterol were analyzed, using gas chromatography‐mass spectrometry, and were characterized as Δ5‐avenasterol two Δ5,23‐stigmastadienols, and Δ5,24(250)‐stigmastadienol. When the unsaponifiables fraction from oat oil was subjected to acid hydrolysis, the two Δ5,23‐stigmastadienol isomers and Δ5,24(25)‐stigmastadienol were detected while fucosterol coeluted with sitosterol. Interisomerization of ethylidene‐side chain sterols represents a limitation to the use of the acid hydrolysis method in the determination of sterols in food and other plant materials rich in these sterols, e.g., oat lipids.
Journal of the Science of Food and Agriculture, 2002
Concentrations and compositions of total lipids (TL), fatty acids, tocopherols and tocotrienols, ... more Concentrations and compositions of total lipids (TL), fatty acids, tocopherols and tocotrienols, avenanthramides and free hydroxycinnamic acids were determined in groats and hulls from single samples of seven Swedish oat cultivars. Total antioxidant capacity (TAC) ...
Alkylresorcinols, phenolic lipids present in high amounts in wholegrain wheat and rye, are of int... more Alkylresorcinols, phenolic lipids present in high amounts in wholegrain wheat and rye, are of interest as potential biomarkers of the intake of these cereals. Alkylresorcinols are known to be absorbed by humans and animals, but little is known about their metabolism or resulting metabolites. A preliminary human study was carried out to identify alkylresorcinol metabolites in human urine. Urine samples, collected before and after a wheat-bran based meal, were deconjugated with beta-glucuronidase/sulphatase and then extracted with ethyl acetate. Extracts were separated by thin-layer chromatography, and fractions containing alkylresorcinols and possible metabolites were identified by retention on the plate compared to standard compounds, and staining with fast blue B. These fractions were further analysed by gas chromatography-mass spectrometry. Deconjugated human urine after the wheat-bran based meal contained two alkylresorcinol metabolites, 3,5-dihydroxybenzoic acid and 3-(3,5-dihydroxyphenyl)-1-propanoic acid, as well as smaller amounts of unchanged alkylresorcinols, confirming the hypothesis that alkylresorcinols are metabolised in humans via beta-oxidation of their alkyl chain.
The effects of various commercial hydrothermal processes (steaming, autoclaving, and drum drying)... more The effects of various commercial hydrothermal processes (steaming, autoclaving, and drum drying) on levels of selected oat antioxidants were investigated. Steaming and flaking of dehulled oat groats resulted in moderate losses of tocotrienols, caffeic acid, and the avenanthramide Bp (N-(4&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;-hydroxy)-(E)-cinnamoyl-5-hydroxy-anthranilic acid), while ferulic acid and vanillin increased. The tocopherols and the avenanthramides Bc (N-(3&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;,4&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;-dihydroxy-(E)-cinnamoyl-5-hydroxy-anthranilic acid) and Bf (N-(4&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;-hydroxy-3&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;-methoxy)-(E)-cinnamoyl-5-hydroxy-anthranilic acid) were not affected by steaming. Autoclaving of grains (including the hulls) caused increased levels of all tocopherols and tocotrienols analyzed except beta-tocotrienol, which was not affected. Vanillin and ferulic and p-coumaric acids also increased, whereas the avenanthramides decreased, and caffeic acid was almost completely eliminated. Drum drying of steamed rolled oats resulted in an almost complete loss of tocopherols and tocotrienols, as well as a large decrease in total cinnamic acids and avenanthramides. The same process applied to wholemeal made from groats from autoclaved grains resulted in less pronounced losses, especially for the avenanthramides which were not significantly affected.
Journal of the American Oil Chemists' Society, 1998
The antipolymerization effects of α‐ and γ‐tocopherols were compared in model systems composed of... more The antipolymerization effects of α‐ and γ‐tocopherols were compared in model systems composed of purified high‐oleic sunflower triacylglycerols at 180°C. γ‐Tocopherol was much more effective as an antipolymerization inhibitor than α‐tocopherol, partly due to lower oxidizability/disappearance. Purified triacylglycerols of sunflower, rapeseed, and high‐oleic sunflower oils were less stable than their nonpurified forms containing tocopherols. Results confirmed that tocopherols per se can act as antipolymerization agents in high‐oleic oils at frying temperatures. No synergism was observed when α‐ and γ‐tocopherols were present together although larger amounts of residuals were left for both tocols. Results suggested that high‐oleic/high‐γ‐tocopherol oils (such as high‐oleic canola and high‐oleic soybean oils) may provide better frying oils than high‐oleic/high‐α‐tocopherol oils (such as high‐oleic sunflower oil).
Journal of the American Oil Chemists' Society, 1994
Seeds from different collections of cultivatedSesamum indicum Linn and three related wild species... more Seeds from different collections of cultivatedSesamum indicum Linn and three related wild species [specifically,S. alatum Thonn.,S. radiatum Schum & Thonn. andS. angustifolium (Oliv.) Engl.] were studied for their oil contents and fatty acid composition of the total lipids. The oils from wild seeds were characterized by higher percentages of unsaponifiables (4.9, 2.6 and 3.7%, respectively) compared toS. indicum (1.4–1.8%), mainly due to their high contents of lignans. Total sterols accounted forca. 40, 22, 20 and 16% of the unsaponifiables of the four species, respectively. The four species were different in the relative percentages of the three sterol fractions (the desmethyl, monomethyl and dimethyl sterols) and in the percentage composition of each fraction. Campesterol, stigmasterol, sitosterol and Δ5‐avenasterol were the major desmethyl sterols, whereas obtusifoliol, gramisterol, cycloeucalenol and citrostandienol were the major monomethyl sterols, and α‐amyrin, β‐amyrin, cycl...
Free amino acids were extracted from cereal products using 50% ethanol to prevent solubilization ... more Free amino acids were extracted from cereal products using 50% ethanol to prevent solubilization of polysaccharides and other viscous polymers and to avoid starch gelatinization. The extracts were analyzed by GC after ion-exchange solid phase extraction and chloroformate derivatization using Ez-Faast technology (Phenomenex). Free amino acids in cereal products could be analyzed within 1h of extraction and determination, with good separation between peaks and repeatable retention times. Relative correction factor for each amino acid was established. The matrix did not affect the results and the method was repeatable for most of the amino acids (coefficient of variation was in the order of 10%). Different fractions and products of wheat, rye, oats and barely were analyzed. The bran contained more free amino acids than did the other analysed fractions of cereals. Fermentation seemed to consume free asparagine and aspartic acid and to use or release other amino acids.
Interactions between &amp;amp;amp;amp;amp;amp;amp;#33-tocopherol (&amp;amp;amp;amp;amp;am... more Interactions between &amp;amp;amp;amp;amp;amp;amp;#33-tocopherol (&amp;amp;amp;amp;amp;amp;amp;#33-TOH) and lipid hydroperoxides (LOOH) during the oxidation of methyl linoleate were studied in a model system using the response surface methodology statistical technique. When no &amp;amp;amp;amp;amp;amp;amp;#33-TOH is present, LOOH had only slight pro-oxidative effects on the oxidation of methyl linoleate. High initial levels of &amp;amp;amp;amp;amp;amp;amp;#33-TOH caused increased consumption and loss of efficiency for this antioxidant. The
Journal of chromatography. B, Analytical technologies in the biomedical and life sciences, 2015
High throughput GC-MS methods for quantification of alkylresorcinols (AR), biomarkers of whole gr... more High throughput GC-MS methods for quantification of alkylresorcinols (AR), biomarkers of whole grain wheat and rye intake, in plasma and adipose tissue and their metabolites in urine were developed and optimised. Alkylresorcinols in plasma (200μL) and adipose tissues (10-50mg) were extracted with diethyl ether, whereas main AR metabolites such as DHBA and DHPPA and newly identified metabolites in urine (50μL) were extracted with ethyl acetate after enzymatic deconjugation. All extracts were purified on OASIS-MAX solid phase extraction cartridges. Plasma and adipose tissue sample extracts were then derivatised with trifluoroacetic anhydride and reconstituted in undecane, whereas AR metabolites in urine samples were derivatised with BSTFA+TMCS (99:1, v/v, 100μL). Prepared samples were quantified by GC-MS (EI-SIM). Analysis of all compounds in the different matrices showed good selectivity, sensitivity, linearity, precision (<15% within and between batches), adequate recovery (75-10...
The effects of dietary (+)-catechin (CAT) and BHT on plasma and tissue concentrations of alpha-to... more The effects of dietary (+)-catechin (CAT) and BHT on plasma and tissue concentrations of alpha-tocopherol (alpha-T), gamma-tocopherol (gamma-T) and cholesterol (C) were studied in male Sprague-Dawley rats. The rats were fed the compounds during a 4-wk period at concentrations of 2 g/kg in standardized diets, low but adequate in vitamin E, with 2 g/kg cholesterol. The CAT-regimen did not affect weight gain, feed intake or organ weights. BHT did not affect feed intake but lowered the body weight and the amount of liver lipids and increased the weights of livers and lungs relative to the body weight. Rats consuming CAT had 2.5-3.5-fold increased plasma, liver and lung alpha-T concentrations, but C concentrations remained unchanged. BHT-feeding resulted in 2.4- and 1.7-fold elevation in alpha-T but approximately 50% decrease in gamma-T concentrations in blood plasma and liver, respectively. BHT also lowered total C in the liver without affecting the concentration of C in the liver lipid...
Background:-Tocopherol has unique properties that may be ben- eficial in sustaining optimal human... more Background:-Tocopherol has unique properties that may be ben- eficial in sustaining optimal human health, but hepatic vitamin E metabolism enhances -tocopherol turnover. Objective: Our aim was to determine the extent to which dietary sesame lignans alter human - and -tocopherol metabolism and elimination as carboxyethyl hydroxychromanols (CEHCs). Design: Healthy participants (n 5 women and 5 men) in a ran- domized, crossover study (with 4-wk washout) consumed muffins prepared with either corn oil or unrefined sesame oil (sesamin, 94 mg; sesamolin, 42 mg), along with a capsule containing a 1:1 molar ratio of deuterium-labeled d6-- and d2--tocopherol acetates (50 mgeach).Plasmaandurinewerecollectedupto72h;unlabeledand labeled tocopherol and CEHC concentrations were determined by liquid chromatography-mass spectrometry. Results:Sesame oil muffin consumption in men, but not in women, decreased(P0.05)areasunderplasmad2--CEHCconcentration-
Six groups of rats were fed diets low, but adequate, in α‐tocopherol but high in γ‐tocopherol. Th... more Six groups of rats were fed diets low, but adequate, in α‐tocopherol but high in γ‐tocopherol. The six diets differed only in their contents (0, 0.25, 0.5, 1.0, 2.0, and 4.0 g/kg, respectively) of sesamin, a lignan from sesame oil. After four weeks ofad libitum feeding, the rats were sacrificed and the concentrations of α‐ and γ‐tocopherols were measured in the plasma, livers, and lungs. Sesamin‐feeding increased γ‐tocopherol and γ‐/α‐tocopherol ratios in the plasma (P<0.05), liver (P<0.001), and lungs (P<0.001). The increase was non‐significant for α‐tocopherol. Thus, sesamin appears to spare γ‐tocopherol in rat plasma and tissues, and this effect persists in the presence of α‐tocopherol, a known competitor to γ‐tocopherol. This suggests that the bioavailability of γ‐tocopherol is enhanced in phenol‐containing diets as compared with purified diets.
This work shows that fucosterol, Δ5‐avenasterol, and similar ethylidene‐side chain sterols can un... more This work shows that fucosterol, Δ5‐avenasterol, and similar ethylidene‐side chain sterols can undergo acid‐catalyzed isomerization to give a mixture of five isomers. Four isomers formed from fucosterol were analyzed, using gas chromatography‐mass spectrometry, and were characterized as Δ5‐avenasterol two Δ5,23‐stigmastadienols, and Δ5,24(250)‐stigmastadienol. When the unsaponifiables fraction from oat oil was subjected to acid hydrolysis, the two Δ5,23‐stigmastadienol isomers and Δ5,24(25)‐stigmastadienol were detected while fucosterol coeluted with sitosterol. Interisomerization of ethylidene‐side chain sterols represents a limitation to the use of the acid hydrolysis method in the determination of sterols in food and other plant materials rich in these sterols, e.g., oat lipids.
Journal of the Science of Food and Agriculture, 2002
Concentrations and compositions of total lipids (TL), fatty acids, tocopherols and tocotrienols, ... more Concentrations and compositions of total lipids (TL), fatty acids, tocopherols and tocotrienols, avenanthramides and free hydroxycinnamic acids were determined in groats and hulls from single samples of seven Swedish oat cultivars. Total antioxidant capacity (TAC) ...
Alkylresorcinols, phenolic lipids present in high amounts in wholegrain wheat and rye, are of int... more Alkylresorcinols, phenolic lipids present in high amounts in wholegrain wheat and rye, are of interest as potential biomarkers of the intake of these cereals. Alkylresorcinols are known to be absorbed by humans and animals, but little is known about their metabolism or resulting metabolites. A preliminary human study was carried out to identify alkylresorcinol metabolites in human urine. Urine samples, collected before and after a wheat-bran based meal, were deconjugated with beta-glucuronidase/sulphatase and then extracted with ethyl acetate. Extracts were separated by thin-layer chromatography, and fractions containing alkylresorcinols and possible metabolites were identified by retention on the plate compared to standard compounds, and staining with fast blue B. These fractions were further analysed by gas chromatography-mass spectrometry. Deconjugated human urine after the wheat-bran based meal contained two alkylresorcinol metabolites, 3,5-dihydroxybenzoic acid and 3-(3,5-dihydroxyphenyl)-1-propanoic acid, as well as smaller amounts of unchanged alkylresorcinols, confirming the hypothesis that alkylresorcinols are metabolised in humans via beta-oxidation of their alkyl chain.
The effects of various commercial hydrothermal processes (steaming, autoclaving, and drum drying)... more The effects of various commercial hydrothermal processes (steaming, autoclaving, and drum drying) on levels of selected oat antioxidants were investigated. Steaming and flaking of dehulled oat groats resulted in moderate losses of tocotrienols, caffeic acid, and the avenanthramide Bp (N-(4&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;-hydroxy)-(E)-cinnamoyl-5-hydroxy-anthranilic acid), while ferulic acid and vanillin increased. The tocopherols and the avenanthramides Bc (N-(3&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;,4&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;-dihydroxy-(E)-cinnamoyl-5-hydroxy-anthranilic acid) and Bf (N-(4&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;-hydroxy-3&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;-methoxy)-(E)-cinnamoyl-5-hydroxy-anthranilic acid) were not affected by steaming. Autoclaving of grains (including the hulls) caused increased levels of all tocopherols and tocotrienols analyzed except beta-tocotrienol, which was not affected. Vanillin and ferulic and p-coumaric acids also increased, whereas the avenanthramides decreased, and caffeic acid was almost completely eliminated. Drum drying of steamed rolled oats resulted in an almost complete loss of tocopherols and tocotrienols, as well as a large decrease in total cinnamic acids and avenanthramides. The same process applied to wholemeal made from groats from autoclaved grains resulted in less pronounced losses, especially for the avenanthramides which were not significantly affected.
Journal of the American Oil Chemists' Society, 1998
The antipolymerization effects of α‐ and γ‐tocopherols were compared in model systems composed of... more The antipolymerization effects of α‐ and γ‐tocopherols were compared in model systems composed of purified high‐oleic sunflower triacylglycerols at 180°C. γ‐Tocopherol was much more effective as an antipolymerization inhibitor than α‐tocopherol, partly due to lower oxidizability/disappearance. Purified triacylglycerols of sunflower, rapeseed, and high‐oleic sunflower oils were less stable than their nonpurified forms containing tocopherols. Results confirmed that tocopherols per se can act as antipolymerization agents in high‐oleic oils at frying temperatures. No synergism was observed when α‐ and γ‐tocopherols were present together although larger amounts of residuals were left for both tocols. Results suggested that high‐oleic/high‐γ‐tocopherol oils (such as high‐oleic canola and high‐oleic soybean oils) may provide better frying oils than high‐oleic/high‐α‐tocopherol oils (such as high‐oleic sunflower oil).
Journal of the American Oil Chemists' Society, 1994
Seeds from different collections of cultivatedSesamum indicum Linn and three related wild species... more Seeds from different collections of cultivatedSesamum indicum Linn and three related wild species [specifically,S. alatum Thonn.,S. radiatum Schum & Thonn. andS. angustifolium (Oliv.) Engl.] were studied for their oil contents and fatty acid composition of the total lipids. The oils from wild seeds were characterized by higher percentages of unsaponifiables (4.9, 2.6 and 3.7%, respectively) compared toS. indicum (1.4–1.8%), mainly due to their high contents of lignans. Total sterols accounted forca. 40, 22, 20 and 16% of the unsaponifiables of the four species, respectively. The four species were different in the relative percentages of the three sterol fractions (the desmethyl, monomethyl and dimethyl sterols) and in the percentage composition of each fraction. Campesterol, stigmasterol, sitosterol and Δ5‐avenasterol were the major desmethyl sterols, whereas obtusifoliol, gramisterol, cycloeucalenol and citrostandienol were the major monomethyl sterols, and α‐amyrin, β‐amyrin, cycl...
Free amino acids were extracted from cereal products using 50% ethanol to prevent solubilization ... more Free amino acids were extracted from cereal products using 50% ethanol to prevent solubilization of polysaccharides and other viscous polymers and to avoid starch gelatinization. The extracts were analyzed by GC after ion-exchange solid phase extraction and chloroformate derivatization using Ez-Faast technology (Phenomenex). Free amino acids in cereal products could be analyzed within 1h of extraction and determination, with good separation between peaks and repeatable retention times. Relative correction factor for each amino acid was established. The matrix did not affect the results and the method was repeatable for most of the amino acids (coefficient of variation was in the order of 10%). Different fractions and products of wheat, rye, oats and barely were analyzed. The bran contained more free amino acids than did the other analysed fractions of cereals. Fermentation seemed to consume free asparagine and aspartic acid and to use or release other amino acids.
Interactions between &amp;amp;amp;amp;amp;amp;amp;#33-tocopherol (&amp;amp;amp;amp;amp;am... more Interactions between &amp;amp;amp;amp;amp;amp;amp;#33-tocopherol (&amp;amp;amp;amp;amp;amp;amp;#33-TOH) and lipid hydroperoxides (LOOH) during the oxidation of methyl linoleate were studied in a model system using the response surface methodology statistical technique. When no &amp;amp;amp;amp;amp;amp;amp;#33-TOH is present, LOOH had only slight pro-oxidative effects on the oxidation of methyl linoleate. High initial levels of &amp;amp;amp;amp;amp;amp;amp;#33-TOH caused increased consumption and loss of efficiency for this antioxidant. The
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