Simultaneous Determination of α‐Tocopheryl Acetate, Tocopherols and Tocotrienols by HPLC with Fluorescence Detection in Foods

Balz, Marion; Schulte, E.; Thier, Hans‐Peter

doi:10.1002/lipi.19930950603

Cited by 58 publications

(60 citation statements)

References 9 publications

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“…The concentration of a-tocopherol was determined by HPLC (Balz et al 1993). Tissue homogenate was saponified with NaOH in the presence of pyrogallol as an antioxidant.…”

Section: Sample Collection and Analysismentioning

confidence: 99%

Cobalt–deficiency–induced hyperhomocysteinaemia and oxidative status of cattle

et al. 2000

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In ruminants, Co is required for the synthesis of vitamin B 12 , which in turn is needed for the resynthesis of methionine by methylation of homocysteine and thus, cobalamin deficiency may induce hyperhomocysteinaemia which is brought into context with perturbations of the antioxidative-prooxidative balance. The present study was conducted to explore whether Co deficiency in cattle is also associated with homocysteine-induced disturbances of oxidative status. Co deficiency was induced in cattle by feeding two groups of animals on either a basal maize-silage-based diet that was moderately low in Co (83 g Co/kg DM), or the same diet supplemented with Co to a total of 200 g Co/kg DM, for 43 weeks. Co deficiency was apparent from a reduced vitamin B 12 status in serum and liver and an accumulation of homocysteine in plasma which was in excess of 4⋅8 times higher in Co-deprived cattle than in controls. The much increased level of circulating homocysteine did not indicate severe disturbances in antioxidantprooxidant balance as measured by individual markers of lipid peroxidation, protein oxidation, and the antioxidative defence system. There were no quantitative difference in plasma thiol groups, nor were there significant changes in concentrations of a-tocopherol, microsomal thiobarbituric acid-reactive substances and carbonyl groups in liver. However, there was a trend toward increased plasma carbonyl levels indicating a slight degradation of plasma proteins in the hyperhomocysteinaemic cattle. Analysis of the hepatic catalase (EC 1.11.1.6) activity revealed an 11 % reduction in Co-deficient cattle relative to the controls. These results indicate that long-term moderate Co deficiency may induce a severe accumulation of plasma homocysteine in cattle, but considerable abnormalities in oxidative status failed to appear.

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“…The concentration of a-tocopherol was determined by HPLC (Balz et al 1993). Tissue homogenate was saponified with NaOH in the presence of pyrogallol as an antioxidant.…”

Section: Sample Collection and Analysismentioning

confidence: 99%

Cobalt–deficiency–induced hyperhomocysteinaemia and oxidative status of cattle

et al. 2000

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“…In recent years, concentrations of vitamin E and carotenoids of several grain products and vegetables were characterized by determination via HPLC [3][4][5][6][7]. Besides the HPLC there are traditional simple and fast methods preferably in grain to detect the yellowness of carotenoid extracts by photometry according to the standard method of the International Association for Cereal Science and Technology [8].…”

Section: Introductionmentioning

confidence: 99%

Analysis of carotenoids and vitamin E in selected oilseeds, press cakes and oils

Franke

Fröhlich

Werner

et al. 2010

Euro J Lipid Sci & Tech

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Carotenoids and vitamin E in oils from the market -6 rapeseed and 6 sunflower oils, half of each cold pressed and refined -and in the oils of rape, sunflower, flax and safflower as well as the respective seeds and press cakes from a local oil mill were quantified by HPLC. Furthermore, a photometric determination of carotenoid content was tested and checked against the chromatographic method. In the cold pressed oils minor amounts of xanthophylls (all-E)-lutein and (all-E)-zeaxanthin were determined. With exception of traces of (all-E)-b-carotene in cold-pressed rapeseed oil this provitamin A active compound did not occur. Cold pressed rapeseed oils contained 0.5-1.5 mg total carotenoids/100 g which was manifold the content of the further oils. Vitamin E was found in all vegetable oils at plant-typic tocopherol patterns. The photometric determination of carotenoids resulted in significantly higher concentrations compared to the HPLC. This overestimation bases on the carotenoid pattern which was validated by comparison with known high-carotenoid materials, i.e. maize flour with an abundant amount of xanthophylls and carrots with an abundant amount of carotenes.

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“…Concentrations of individual tocopherols in plasma, liver, LDL, and dietary fats were determined using a high-performance liquid chromatography (HPLC) method [27]. After saponification with saturated sodium hydroxide solution, individual tocopherols were extracted with n-hexane and separated isocratically on a HP 1100 HPLC station (Hewlett Packard, Waldbronn, Deutschland) using a mixture of n-hexane and 1,4 dioxane (96:4, v/v) as mobile phase and a LiChrosorb Si 60 column (5 µm particle size, 250 mm length, 4 mm internal diameter, Merck Eurolab) and detected by fluorescence.…”

Section: Analysesmentioning

confidence: 99%

Effects of dietary fish oil and oxidized cholesterol on the concentration of 7β‐hydroxycholesterol in liver, plasma, low density lipoproteins and erythrocytes of rats at various vitamin E supply

Ringseis

Eder

2003

Euro J Lipid Sci & Tech

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Effects of dietary fish oil and oxidized cholesterol on the concentration of 7β β-hydroxycholesterol in liver, plasma, low density lipoproteins and erythrocytes of rats at various vitamin E supplyTwo experiments with rats were carried out to investigate the effect of dietary fish oil and oxidized cholesterol on the concentration of 7β-hydroxycholesterol, an oxysterol of mainly nonenzymatic origin, in liver, plasma, low density lipoproteins and erythrocytes of rats at different vitamin E supply. In Experiment 1, four groups of rats received diets with coconut oil or salmon oil (100 g/kg diet) and vitamin E concentrations of 40 or 240 mg α-tocopherol equivalents/kg. In Experiment 2, eight groups of rats received diets supplemented with pure or oxidized cholesterol (5 g/kg), coconut oil or salmon oil (100 g/kg diet) and vitamin E concentrations of 40 or 240 mg α-tocopherol equivalents/kg. Rats fed the salmon oil diets had significantly higher concentrations of 7β-hydroxycholesterol in liver, plasma, low density lipoproteins and erythrocytes than rats fed coconut oil diets. Rats fed the diets supplemented with oxidized cholesterol had significantly higher concentrations of 7β-hydroxycholesterol in all the samples analyzed than rats fed pure cholesterol. Increasing the dietary vitamin E concentration from 40 to 240 mg α-tocopherol equivalents/kg diet reduced the concentration of 7β-hydroxycholesterol in plasma; the concentrations of 7β-hydroxycholesterol in liver, low density lipoproteins and erythrocytes were not influenced by the dietary vitamin E concentration. The study suggests that diets with fish oil or oxidized cholesterol are critical with respect to the formation of 7β-hydroxycholesterol.

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Simultaneous Determination of α‐Tocopheryl Acetate, Tocopherols and Tocotrienols by HPLC with Fluorescence Detection in Foods

Cited by 58 publications

References 9 publications

Cobalt–deficiency–induced hyperhomocysteinaemia and oxidative status of cattle

Cobalt–deficiency–induced hyperhomocysteinaemia and oxidative status of cattle

Analysis of carotenoids and vitamin E in selected oilseeds, press cakes and oils

Effects of dietary fish oil and oxidized cholesterol on the concentration of 7β‐hydroxycholesterol in liver, plasma, low density lipoproteins and erythrocytes of rats at various vitamin E supply

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