Brüls-Gill Mariska, Boerkamp Vincent J P, Hohlbein Johannes, van Duynhoven John P M
Laboratory of Biophysics, Wageningen University and Research, Stippeneng 4, 6708 WE, Wageningen, the Netherlands.
Laboratory of Self-Organizing Soft Matter, Department of Chemical Engineering and Chemistry & Institute for Complex Molecular Systems, Eindhoven University of Technology, P.O. Box 513, 5600 MB, Eindhoven, the Netherlands.
Curr Res Food Sci. 2024 Aug 5;9:100817. doi: 10.1016/j.crfs.2024.100817. eCollection 2024.
The growing trend of substituting animal-based proteins with plant-based proteins requires more understanding of the functionality and stability of vegan mayonnaises, especially regarding their susceptibility to lipid and protein oxidation. Here, we investigate the spatial and temporal dynamics of lipid and protein oxidation in emulsions stabilized with legume ((hydrolyzed) soy, pea, and faba bean) protein isolates (hSPI, SPI, PPI, FPI). We assessed lipid oxidation globally by NMR and locally by confocal laser scanning microscopy using the oxidation-sensitive fluorescent dye BODIPY 665/676. Further, we assessed local protein oxidation by employing protein autofluorescence and the fluorescently labeled radical spin-trap CAMPO-AFDye 647. Oxidation of oil in droplets was governed by the presence of tocopherols in the oil phase and pro-oxidant transition metals that were introduced via the protein isolates. Non-stripped oil emulsions stabilized with PPI and hSPI displayed higher levels of lipid hydroperoxides as compared to emulsions prepared with SPI and FPI. We attribute this finding to higher availability of catalytically active transition metals in PPI and hSPI. For stripped oil emulsions stabilized with SPI and FPI, lipid hydroperoxide concentrations were negligible in the presence of ascorbic acid, indicating that this agent acted as antioxidant. For the emulsions prepared with PPI and hSPI, lipid hydroperoxide formation was only partly inhibited by ascorbic acid, indicating a role as prooxidant. Interestingly, we observed protein-lipid aggregates in all emulsions. The aggregates underwent fast and extensive co-oxidation, which was also modulated by transition metals and tocopherols originating from the oil phase. Our study demonstrates the potential of spatiotemporal imaging techniques to enhance our understanding of the oxidation processes in emulsions stabilized with plant proteins.
用植物性蛋白质替代动物性蛋白质的趋势日益增长，这就需要我们对纯素蛋黄酱的功能和稳定性有更多的了解，尤其是它们对脂质和蛋白质氧化的敏感性。在此，我们研究了用豆类（水解大豆、豌豆和蚕豆）分离蛋白（hSPI、SPI、PPI、FPI）稳定的乳液中脂质和蛋白质氧化的时空动态。我们通过核磁共振全局评估脂质氧化，并使用对氧化敏感的荧光染料BODIPY 665/676通过共聚焦激光扫描显微镜局部评估脂质氧化。此外，我们通过利用蛋白质自发荧光和荧光标记的自由基自旋捕集剂CAMPO-AFDye 647评估局部蛋白质氧化。油滴中的油氧化受油相中生育酚和通过分离蛋白引入的促氧化过渡金属的影响。与用SPI和FPI制备的乳液相比，用PPI和hSPI稳定的未脱脂油乳液显示出更高水平的脂质氢过氧化物。我们将这一发现归因于PPI和hSPI中催化活性过渡金属的可用性更高。对于用SPI和FPI稳定的脱脂油乳液，在存在抗坏血酸的情况下，脂质氢过氧化物浓度可忽略不计，这表明该试剂起到了抗氧化剂的作用。对于用PPI和hSPI制备的乳液，抗坏血酸仅部分抑制脂质氢过氧化物的形成，表明其起到了促氧化剂的作用。有趣的是，我们在所有乳液中都观察到了蛋白质-脂质聚集体。这些聚集体经历了快速而广泛的共氧化，这也受到来自油相的过渡金属和生育酚的调节。我们的研究证明了时空成像技术在增强我们对植物蛋白稳定乳液中氧化过程理解方面的潜力。
