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Publications (5)13.57 Total impact

  • Article: Enrichment of eggs with n−3 polyunsaturated fatty acids: Effects of vitamin E supplementation
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    ABSTRACT: Eggs enriched with n−3 polyunsaturated fatty acids (PUFA) could contribute to dietary intake of these healthful fatty acids (FA). Because n−3 PUFA are highly susceptible to peroxidation, a first part of the study with Leghorn laying hens was carried out to investigate the influence of different levels of fish oil (0, 0.7, 1.4, 2.8, or 5.6%, respectively) in the diet on n−3 PUFA, cholesterol, vitamin E, and lipid peroxidation product contents in eggs. Addition of fish oil to a complete diet based on wheat, rye, tapioca, and soybean constituents containing 11 IU vitamin E/kg resulted in increased n−3 PUFA content in egg yolk, mainly due to accumulation of docosahexaenoic acid. Cholesterol was not altered up to 2.8% fish oil in the diet. The vitamin E content of the yolk was insufficient for the protection of PUFA from peroxidation. Addition of up to 2.8% fish oil to laying hen diets increased the n−3 PUFA content of yolks with a concomitant imbalance between vitamin E and PUFA, leading to increased levels of cytotoxic aldehydic lipid peroxidation products such as malondialdehyde (MDA). In a second part of the studies, the balance between vitamin E, PUFA, and lipid peroxidation was analyzed during the period of storage of n−3 PUFA-enriched eggs produced after feeding the laying hens with 1.5% fish oil diets with different concentrations of vitamin E (0, 5, 10, 20, 40, 80, 160 IU/kg). Storage of eggs resulted in a marked loss of vitamin E in yolk. In stored eggs, the cytotoxic lipid peroxidation products MDA, 4-hydroxynonenal, and 4-hydroxyhexenal were reduced in response to vitamin E supplementation. To prevent the increase of cytotoxic aldehydic lipid peroxidation during production and storage of n−3 PUFA-enriched eggs, a high vitamin E supplementation with at least 80 IU vitamin E/kg is needed.
    Lipids 04/2012; 36(8):833-838. · 2.13 Impact Factor
  • Article: Letter to the Editor regarding the review paper by Dersjant-Li and Peisker.
    Peter P Hoppe
    J Anim Physiol a Anim Nutr 08/2010; 94(4):547-8. · 0.86 Impact Factor
  • Article: Novel lycopene metabolites are detectable in plasma of preruminant calves after lycopene supplementation.
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    ABSTRACT: Appropriate animal models such as preruminant calves are necessary to study the complex physiological functions of carotenoids and to relate them to possible health effects in humans. In this study, the bioavailability and metabolism of lycopene from 2 dietary supplements were compared. LycoVit containing synthetic lycopene and Lyc-O-Mato containing natural tomato oleoresin were administered to 2 groups of preruminant calves (each n = 8) for 14 d in daily doses of 15 mg of lycopene. Plasma was analyzed for carotenoids before the intervention period, directly after, and each day for 5 d after the end of the intervention. All-trans and 5-cis lycopene, and 3 lycopene metabolites not previously found in calf plasma were detected. These metabolites contributed 52% of the total lycopene content measured at the end of the intervention period. Based on spectroscopic data, they might be hydrogenation products, which are formed from all-trans and/or 5-cis lycopene. In the LycoVit group, total lycopene concentrations were approximately 300% higher (286 +/- 89 nmol/L) than in the Lyc-O-Mato group (72 +/- 33 nmol/L) (P < 0.001). This indicates that, unlike in humans, lycopene from LycoVit and Lyc-O-Mato does not have equal bioavailabilities in preruminant calves. Therefore, the preruminant calf may not be a suitable animal model with which to study the biological and physiological effects of lycopene.
    Journal of Nutrition 12/2005; 135(11):2616-21. · 3.92 Impact Factor
  • Article: Synthetic and tomato-based lycopene have identical bioavailability in humans.
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    ABSTRACT: Bioavailability studies with lycopene have focused on natural sources. A synthetic source has recently become available. To determine the relative bioavailabilities of synthetic and tomato-based lycopene in free living volunteers in a single-blind, randomized, placebo-controlled, parallel trial. Three groups (n=12/group) of healthy, normolipemic male and female subjects with a mean baseline serum lycopene concentration of 0.36 micro mol/L took a dose of 15 mg/day total lycopene for 28 days from either Lycovit 10% (beadlets, BASF, Germany) or Lyc-O-Mato (beads, LycoRed Natural Products, Israel) or a placebo (without lycopene) together with the main meal. The increase in serum lycopene from baseline was used as the parameter of bioavailability. Synthetic and tomato-lycopene resulted in significant increases above baseline of serum total lycopene by 0.58 and 0.57 micro mol/L, trans-lycopene by 0.34 and 0.41 micro mol/L, and total-cis-lycopene by 0.24 and 0.16 micro mol/L, whereas no significant changes were found in the placebo treatment. The mean serum total lycopene response to synthetic and natural lycopene was not significantly different. Neither lycopene source affected the other serum carotenoids, viz. alpha-carotene, beta-carotene, beta-cryptoxanthin, zeaxanthin and lutein. We conclude that synthetic and natural lycopene are equivalent sources of lycopene and that there is no interaction with other circulating carotenoids.
    European Journal of Nutrition 11/2003; 42(5):272-8. · 2.75 Impact Factor
  • Article: Serum response of ponies to beta-carotene fed by grass meal or a synthetic beadlet preparation with and without added dietary fat.
    Journal of Nutrition 07/2002; 132(6 Suppl 2):1774S-5S. · 3.92 Impact Factor