TY - JOUR A1 - Rohner, Fabian A1 - Frey, Simone K. A1 - Mothes, Ralf A1 - Hurtienne, Andrea A1 - Hartong, Simone A1 - Bosso, Patrice Emery A1 - Bui, Mai A1 - Schweigert, Florian J. A1 - Northrop-Clewes, Christine T1 - Quantification of vitamin A in palm oil using a fast and simple portable device method validation and comparison to high-performance liquid chromatography JF - International journal for vitamin and nutrition research N2 - Vitamin A deficiency continues to be a global public health problem. Fortification of oil with vitamin A is considered a cost-effective, feasible strategy to prevent this problem but quality control poses a challenge to program implementation. To overcome this, we have validated a newly developed device that quantitatively measures the content of retinyl palmitate in refined palm oil, is simple to use, and yields immediate results. Linearity of analysis rand from 2.5-30 mg retinol equivalents (RE)/kg of palm oil, with 2.5 mg RE/kg being the determination limit; inter- and intra-assay precision ranged from 1.4-7.1 To. Comparison with a high-performance Liquid chromatography method showed high agreement between the methods (R-2 = 0.92; Limits of Agreement: -1.24 mg to 2.53 mg RE/kg), and further comparisons illustrate that the new device is useful in low resource settings. This device offers a field- and user-friendly solution to quantifying the vitamin A content in refined palm oil. KW - Vitamin A KW - retinyl palmitate KW - fortification KW - monitoring KW - rapid test kit KW - palm oil Y1 - 2011 U6 - https://doi.org/10.1024/0300-9831/a000081 SN - 0300-9831 VL - 81 IS - 5 SP - 335 EP - 342 PB - Hogrefe CY - Bern ER - TY - JOUR A1 - Müller, Kerstin E. A1 - Altenkamp, Rainer A1 - Raila, Jens A1 - Schmidt, Daniel A1 - Dietrich, Robert A1 - Hurtienne, Andrea A1 - Wink, Michael A1 - Krone, Oliver A1 - Brunnberg, Leo A1 - Schweigert, Florian J. T1 - Plasma concentration of alpha-tocopherol in different free-ranging birds of prey JF - European journal of wildlife research N2 - In this study, we investigated the alpha-tocopherol plasma concentrations in healthy free-ranging nestlings of the white-tailed sea eagle (Haliaeetus albicilla) (n=32), osprey (Pandion haliaetus) (n=39), northern goshawk (Accipiter gentilis) (n=25), common buzzard (Buteo buteo) (n=31), and honey buzzard (Pernis apivorus) (n=18) as well as of free-ranging adults of the white-tailed sea eagle (n=10), osprey (n=31), and northern goshawk (n=45). alpha-Tocopherol plasma concentrations were determined by reverse-phase high-performance liquid chromatography. alpha-Tocopherol plasma concentrations in nestlings of osprey, white-tailed sea eagle, and northern goshawk did not differ significantly amongst the species, but the common buzzard and honey buzzard nestlings had significantly lower alpha-tocopherol plasma concentrations than nestlings of the other species (both P<0.001). Adult male ospreys and white-tailed sea eagles had significantly higher alpha-tocopherol concentrations compared to adult females (both P<0.005). Adult ospreys and northern goshawks had significantly higher alpha-tocopherol plasma concentrations compared to their nestlings (both P<0.001). In adult female northern goshawks, plasma concentrations of alpha-tocopherol increased significantly before egg laying (P<0.001). These results demonstrate alpha-tocopherol plasma concentrations in birds of prey to be species specific and influenced by age and reproductive status. KW - alpha-Tocopherol KW - Birds of prey KW - Plasma concentration Y1 - 2011 U6 - https://doi.org/10.1007/s10344-011-0516-z SN - 1612-4642 VL - 57 IS - 5 SP - 1043 EP - 1049 PB - Springer CY - New York ER - TY - JOUR A1 - Raila, Jens A1 - Enjalbert, Francis A1 - Mothes, Ralf A1 - Hurtienne, Andrea A1 - Schweigert, Florian J. T1 - Validation of a new point-of-care assay for determination of ss-carotene concentration in bovine whole blood and plasma JF - Veterinary clinical pathology N2 - Background: beta-Carotene is an important precursor of vitamin A, and is associated with bovine fertility. beta-Carotene concentrations in plasma are used to optimize beta-carotene supplementation in cattle, but measurement requires specialized equipment to separate plasma and extract and measure beta-carotene, either using spectrophotometry or high performance liquid chromatography (HPLC). Objective: The objective of this study was to validate a new 2-step point-of-care (POC) assay for measuring beta-carotene in whole blood and plasma. Methods: beta-carotene concentrations in plasma from 166 cows were measured using HPLC and compared with results obtained using a POC assay, the iCheck-iEx-Carotene test kit. Whole blood samples from 23 of these cattle were also evaluated using the POC assay and compared with HPLC-plasma results from the same 23 animals. The POC assay includes an extraction vial (iEx Carotene) and hand-held photometer (iCheck Carotene). Results: Concentrations of beta-carotene in plasma measured using the POC assay ranged from 0.40 to 15.84 mg/L (n = 166). No differences were observed between methods for assay of plasma (mean +/- SD; n = 166): HPLC-plasma 4.23 +/- 2.35 mg/L; POC-plasma 4.49 +/- 2.36 mg/L. Similar good agreement was found when plasma analyzed using HPLC was compared with whole blood analyzed using the POC system (n = 23): HPLC-plasma 3.46 +/- 2.12 mg/L; POC-whole blood 3.67 +/- 2.29 mg/L. Conclusions: Concentrations of beta-carotene can be measured in blood and plasma from cattle easily and rapidly using a POC assay, and results are comparable to those obtained by the highly sophisticated HPLC method. Immediate feedback regarding beta-carotene deficiency facilitates rapid and appropriate optimization of beta-carotene supplementation in feed. KW - Biomarker KW - HPLC KW - method comparison KW - nutritional supplements KW - vitamin A Y1 - 2012 U6 - https://doi.org/10.1111/j.1939-165X.2012.00400.x SN - 0275-6382 VL - 41 IS - 1 SP - 119 EP - 122 PB - Wiley-Blackwell CY - Malden ER - TY - JOUR A1 - Mueller, K. A1 - Raila, Jens A1 - Altenkamp, Rainer A1 - Schmidt, D. A1 - Dietrich, R. A1 - Hurtienne, Andrea A1 - Wink, M. A1 - Krone, O. A1 - Brunnberg, Leo A1 - Schweigert, Florian J. T1 - Concentrations of retinol, 3,4-didehydroretinol, and retinyl esters in plasma of free-ranging birds of prey JF - Journal of animal physiology and animal nutrition N2 - This study investigated vitamin A compounds in the plasma of healthy free-ranging Central European raptors with different feeding strategies. Plasma samples of nestlings of white-tailed sea eagle [white-tailed sea eagle (WTSE), Haliaeetus albicilla) (n = 32), osprey (Pandion haliaetus) (n = 39), northern goshawk (Accipiter gentilis) (n = 25), common buzzard (Buteo buteo) (n = 31), and honey buzzard (Pernis apivorus) (n = 18) and adults of WTSE (n = 10), osprey (n = 31), and northern goshawk (n = 45) were investigated with reversed-phase-high-performance liquid chromatography (RP-HPLC). In WTSE, northern goshawks and common buzzards retinol were the main plasma component of vitamin A, whilst in ospreys and honey buzzards, 3,4-didehydroretinol predominated. The median of the retinol plasma concentration in the nestlings group ranged from 0.12 to 3.80 mu M and in the adult group from 0.15 to 6.13 mu M. Median plasma concentrations of 3,4-didehydroretinol in nestlings ranged from 0.06 to 3.55 mu M. In adults, northern goshawks had the lowest plasma concentration of 3,4-didehydroretinol followed by WTSE and ospreys. The plasma of all investigated species contained retinyl esters (palmitate, oleate, and stearate). The results show considerable species-specific differences in the vitamin A plasma concentrations that might be caused by different nutrition strategies. KW - birds of prey KW - plasma KW - retinol KW - 3,4-didehydroretinol KW - retinyl esters Y1 - 2012 U6 - https://doi.org/10.1111/j.1439-0396.2011.01219.x SN - 0931-2439 VL - 96 IS - 6 SP - 1044 EP - 1053 PB - Wiley-Blackwell CY - Hoboken ER - TY - JOUR A1 - Schweigert, Florian J. A1 - Hurtienne, Andrea A1 - Bathe, Katharina T1 - Improved extraction procedure for carotenoids from human milk Y1 - 2000 SN - 0300-9831 ER - TY - JOUR A1 - Schweigert, Florian J. A1 - Klinger, Jeannine A1 - Hurtienne, Andrea A1 - Zunft, Hans-Joachim Franz T1 - Vitamin A, carotenoid and vitamin E plasma concentrations in children from Laos in relation to sex and growth failure Y1 - 2003 UR - http://www.nutritionj.com/content/2/1/17 ER - TY - JOUR A1 - Löhrke, B. A1 - Vierguth, T. A1 - Kanitz, W. A1 - Göllnitz, K. A1 - Becker, F. A1 - Hurtienne, Andrea A1 - Schweigert, Florian J. T1 - High milk yield in dairy cows associated with oxidant stress Y1 - 2004 SN - 1328-925X ER - TY - JOUR A1 - Lohrke, B. A1 - Viergutz, L. A1 - Kanitz, W. A1 - Becker, F. A1 - Gollnitz, K. A1 - Hurtienne, Andrea A1 - Schweigert, Florian J. T1 - Relationship between oxidant stress and milk productivity in dairy cows N2 - An imbalance between formation and detoxification of oxygen radicals leads to oxidant stress that may increase in more intense oxidative metabolism caused by a high intake of metabolizable energy to provide metabolic intermediates for the milk synthesis and secretion. This hypothesis was tested using dairy cows and the concentration of hydroperoxides in lipids (LHP) extracted from circulative lipoprotein particles of low and very low density (LDL and VLDL/chylomicrons) as oxidant stress indicator. The particles were prepared by ultracentrifugation of serum obtained by coccygeal bleeding (13 cows, 1. parity, n=8 and 2. parity, n=5, lactation stage, 53 +/- 1.4 days post partum) and purified by precipitation. Concentrations of LHP-LDL/mg Lipoprotein correlated significantly with daily milk yield (r = 0.73, P = 0.004) or daily milk energy output (r = 0.77, P = 0.003) in contrast to LHP of VLDL/chylomicron particles. Thus, some evidence was obtained for an almost linear, positive relationship between milk productivity and oxidant stress occurring in LDL Y1 - 2005 SN - 0005-9366 ER -