Browsing by Person "Pospiech, Jonas"

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Mineral bioaccessibility and safety assessment of plant-based meat alternatives and targeted enrichment of essential nutrients in a cultured meat cell line model
(2025) Pospiech, Jonas; Frank, Jan
Plant-based meat alternatives (PBMA) and cultured meat have gained recognition as substitutes for conventional meat, and their consumption is expected to increase due to the limited sustainability of traditional meat production systems. Meat is a source of bioaccessible iron and zinc for the general population. Replacing it with plant-based substitutes requires ensuring adequate nutrient intake. However, PBMA are formulated using various plant-based ingredients, leading to substantial variations in nutrient content that can significantly affect the mineral bioaccessibility. Consequently, the replacement of meat with PBMA may influence the intake and status of these minerals at both individual and population levels. Moreover, the preparation of PBMA through pan-frying at temperatures exceeding 120 degrees celsius may lead to the formation of Maillard reaction products, including acrylamide and furanoic compounds, which may pose health risks when consumed in higher amounts. Consequently, this doctoral thesis assessed the bioaccessibility of iron and zinc from commercially available PBMA and investigated the formation of acrylamide and furanoic compounds during pan-frying at different temperatures. The results demonstrated that the PBMA analyzed did not pose a significant health risk to consumers due to their low concentrations of acrylamide and furanoic compounds after pan-frying. In addition, it was shown that even though the bioaccessibility of iron and zinc was impaired by the presence of absorption inhibitors, such as phytate, commercially available PBMA can still contribute to meet the daily recommendations of iron and zinc. The second part of the thesis explored the potential for enriching health-promoting compounds in a cultured meat cell model. A notable finding was the significant accumulation of the omega-3 fatty acid alpha-linolenic acid and ferrous sulfate (iron) without inducing lipid peroxidation, which highlights the potential of targeted enrichment strategies to enhance the nutritional profile of cultured meat, offering a promising approach for the development of healthier and more sustainable meat alternatives.
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.