Browsing by Person "Pospiech, Jonas"

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Plant-based burger patties are a source of bioaccessible iron and zinc
(2025) Pospiech, Jonas; Kruger, Johanita; Frank, Jan
Background: The consumption of plant-based meat alternatives has increased substantially in recent years. However, due to the presence of absorption inhibitors, such as phytate, oxalate, and condensed tannins, the uptake of zinc and iron from plant foods may be low. We therefore quantified minerals (Fe, Zn), inhibitors (phytate, oxalate, condensed tannins), and enhancers (ascorbic acid, carotenoids) of mineral absorption in pea protein-, soy protein-, soy flour-, and sunflower protein-based burger patties and the resulting bioaccessibility of the contained iron and zinc conducting in vitro digestion experiments. Results: The soy flour-based burger had nearly complete bioaccessibility for zinc (105 ± 6 %) and iron (101 ± 11 %), while the three other plant burgers had significantly lower bioaccessibilities (zinc, 9–12 %; iron, 43–57 %). The phytate but not the oxalate and condensed tannin contents of the patties were negatively correlated with the bioaccessibility of iron and zinc (p < 0.05). Conclusion: Plant-based meat alternatives may be an important source of bioaccessible iron and zinc, if they contain low amounts of phytate, and may contribute to an adequate supply of these minerals. Conclusion: Plant-based meat alternatives may be an important source of bioaccessible iron and zinc, if they contain low amounts of phytate, and may contribute to an adequate supply of these minerals.
Prumnopitys andina fruit extract activates liver X receptors after in vitro digestion
(2022) Jiménez‐Aspee, Felipe; Pospiech, Jonas; Bauer, Sarah; Sus, Nadine; Kufer, Thomas A.; Frank, Jan
Scope: 20-Hydroxyecdysone (20E) is the main phytochemical present in the fresh arils of Prumnopitys andina. 20E is reported to have anabolic effects by modulation of gene transcription by interaction with nuclear receptors. Our aim is to evaluate the in vitro bioaccessibility, transepithelial transport of 20E, and the capacity of P. andina fruit extract and 20E to activate selected mammalian nuclear receptors in transiently transfected human cells after simulated gastrointestinal digestion. Results: 20E shows good stability, solubility, and micellization after in vitro digestion. 20E is taken up by Caco-2 cells, but poorly transported through the epithelial cell membrane, possibly due to P-glycoprotein-mediated efflux. In transiently transfected HepG2 cells, the fruit extract significantly induces the signal intensity for the liver X receptor (LXR)-α and -β by 1.6 and 1.4-fold, respectively. In contrast, the treatment with 20E, irrespective of its concentration, did not change the activity of both LXR receptors. No effects are observed for the pregnane X receptor or the constitutive androstane receptor. Conclusion: Our findings show that components of the digested P. andina extract other than 20E are responsible for the effects on LXR-α and -β. Our findings open new perspectives on the potential role of P. andina fruits in cholesterol metabolism and inflammatory diseases.