TY - JOUR A1 - Islam, Khan Shaiful A1 - Khalil, Mahmoud A1 - Männer, K. A1 - Raila, Jens A1 - Rawel, Harshadrai Manilal A1 - Zentek, J. A1 - Schweigert, Florian J. T1 - Effect of dietary alpha-tocopherol on the bioavailability of lutein in laying hen JF - Journal of animal physiology and animal nutrition N2 - Lutein and its isomer zeaxanthin have gained considerable interest as possible nutritional ingredient in the prevention of age-related macular degeneration (AMD) in humans. Egg yolk is a rich source of these carotenoids. As an oxidative sensitive component, antioxidants such as -tocopherol (T) might contribute to an improved accumulation in egg yolk. To test this, chickens were fed lutein esters (LE) with and without -tocopherol as an antioxidant. After depletion on a wheat-soya bean-based lutein-poor diet for 21days, laying hens (n=42) were equally divided into three groups and fed the following diets for 21days: control (basal diet), a LE group (40mg LE/kg feed) and LE+T group (40mg LE plus 100mg T/kg feed). Eggs and blood were collected periodically. Carotenoids and -tocopherol in yolk and blood plasma were determined by HPLC. Egg yolk was also analysed for total carotenoids using a one-step spectrophotometric method (iCheck(())). Lutein, zeaxanthin, -tocopherol and total carotenoids in egg yolk were highest after 14days of feeding and decreased slightly afterwards. At the end of the trial, eggs of LE+T group contained higher amount of lutein (13.72), zeaxanthin (0.65), -tocopherol (297.40) and total carotenoids (21.6) compared to the LE group (10.96, 0.55, 205.20 and 18.0mg/kg, respectively, p<0.05). Blood plasma values of LE+T group contain higher lutein (1.3), zeaxanthin (0.06) and tocopherol (20.1) compared to LE group (1.02, 0.04 and 14.90mg/l, respectively, p<0.05). In conclusion, dietary -tocopherol enhances bioavailability of lutein reflecting higher content in egg yolk and blood plasma. Improved bioavailability might be due to increased absorption of lutein in the presence of tocopherol and/or a greater stability of lutein/zeaxanthin due to the presence of -tocopherol as an antioxidant. KW - carotenoids KW - tocopherol KW - egg yolk KW - bioavailability KW - HPLC KW - iCheck Y1 - 2016 U6 - https://doi.org/10.1111/jpn.12464 SN - 0931-2439 SN - 1439-0396 VL - 100 SP - 868 EP - 875 PB - Wiley-Blackwell CY - Hoboken ER - TY - JOUR A1 - Islam, Khan M. S. A1 - Khalil, Mahmoud Abd Elhamid A1 - Maenner, Klaus A1 - Raila, Jens A1 - Rawel, Harshadrai Manilal A1 - Zentek, Jürgen A1 - Schweigert, Florian J. T1 - Lutein Specific Relationships among Some Spectrophotometric and Colorimetric Parameters of Chicken Egg Yolk JF - The journal of poultry science N2 - Lutein is an essential dietary carotenoid with health benefits and is inter alia responsible for the colouration of egg yolk. The relationship between lutein accumulation and egg yolk colouration was therefore studied in more detail. After feeding a low-luteine diet for 21 days, 14 birds (Lohmann brown hens aged 20 weeks) were fed a diet containing marigold (80 mg lutein/kg feed) and 14 other birds were fed a diet containing oleoresin (45 mg lutein/kg feed) for 21 days; for both groups of birds, this feeding period was followed by withdrawal for 21 days. The Roche Yolk Colour Fan (RYCF) score (0 to 15, where higher values denote greater colour intensity; R-2=0.87; P<0.01) and redness (R-2=0.89; P<0.01) increased with increasing lutein content of egg yolk. Total carotenoid content had a poor relationship with lightness (R-2=0.13; P>0.05) and yellowness (R-2=0.12; P>0.05) of the yolk. It may be concluded that increased lutein is potentially responsible for an increased RYCF score and redness (a*), but decreased yellowness (b*) and lightness (L*), of egg yolk. KW - carotenoid KW - HPLC KW - iCheck KW - lutein KW - spectrophotometry KW - yolk Y1 - 2017 U6 - https://doi.org/10.2141/jpsa.0160065 SN - 1346-7395 VL - 54 SP - 271 EP - 277 PB - Japan Poultry Science Association CY - Tsukuba 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 -