AIMS: The aims of the present work were to encapsulate curcumin in denaturated whey protein isolate and investigate the physicochemical and morphological properties of whey protein isolate‐based nanoparticles (WPI‐NPs). METHODS: Scanning electron microscopy (SEM) was used to investigate the morphological properties of WPI‐NPs. The crystalline structure of the developed NPs was evaluated by using an X‐ray diffraction technique. Antiradical activity of pure and loaded curcumin was also tested. in vitro release of curcumin into the simulated stomach and small intestine was evaluated. The stability of pure and encapsulated curcumin against pH and oxidation was compared. RESULTS: WPI‐NPs had a spherical shape‐like structure with smooth surface. The encapsulation efficiency of curcumin in WPI‐NPs was found to be 93.1%, demonstrating that the encapsulation system used in the present work was effective to entrap curcumin molecules. WPI‐NPs showed more stability at pH 7, indicating that the developed system is suitable for application of beverages with neutral pH. Furthermore, the encapsulation of curcumin into nanoparticles led to improvement of the oxidation stability of curcumin from 10% to 70%. The developed nanoparticles improved the release of curcumin in the simulated gastrointestinal tract. The release of curcumin in simulated gastric medium was low, but in the intestine, most of the curcumins were released in the early hours. The release of curcumin followed non‐Fickian mechanism in the intestine and stomach environment. CONCLUSION: The developed encapsulation system can be introduced as a viable strategy to improve the bioavailability of curcumin. PRACTICAL APPLICATIONS: Considering the diverse biological activity of curcumin and high oxidation stability of WPI‐NPs, the developed nanoparticles can be used as a valuable additive compound in food and pharmaceutical systems, especially in beverages with neutral pH.

中文翻译：

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乳清蛋白包裹姜黄素的稳定性和生物活性评估

目的：本工作的目的是将姜黄素包裹在变性乳清蛋白分离物中，并研究基于乳清蛋白分离物的纳米颗粒（WPI-NPs）的理化和形态特性。方法：使用扫描电子显微镜（SEM）来研究 WPI-NPs 的形态学特性。通过使用 X 射线衍射技术评估开发的 NPs 的晶体结构。还测试了纯姜黄素和负载姜黄素的抗自由基活性。姜黄素在体外释放到模拟胃和小肠中的情况进行了评估。比较了纯姜黄素和包封姜黄素对 pH 和氧化的稳定性。结果：WPI-NPs 具有球形结构，表面光滑。姜黄素在 WPI-NPs 中的包封率为 93.1%，证明本工作中使用的封装系统可有效捕获姜黄素分子。WPI-NPs 在 pH 7 下表现出更高的稳定性，表明所开发的系统适用于中性 pH 饮料的应用。此外，将姜黄素包裹在纳米颗粒中使姜黄素的氧化稳定性从 10% 提高到 70%。开发的纳米颗粒改善了姜黄素在模拟胃肠道中的释放。姜黄素在模拟胃介质中的释放量较低，但在肠道中，大部分姜黄素在早期释放。姜黄素在肠道和胃环境中的释放遵循非菲克机制。结论：开发的封装系统可以作为一种可行的策略来提高姜黄素的生物利用度。