College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, China.
Xinjiang Key Laboratory of Biological Resources and Genetic Engineering, College of Life Science and Technology, Xinjiang University, Urumqi, 830017, China.
Food Chem. 2025 Feb 1;464(Pt 2):141693. doi: 10.1016/j.foodchem.2024.141693. Epub 2024 Oct 18.
The poor techno-functional properties of walnut protein isolate (WPI) limit its application as carrier to improve bioavailability of curcumin. In this study, WPI was modified by pH-shifting (PS) and protein-glutaminase (PG). Changes on the physicochemical and structural characteristics of WPI and effects on complexation with curcumin were investigated. Treatment of PS plus PG increased electrostatic repulsion of WPI with altered secondary and tertiary structure. Solubility of WPI was greatly improved from 18.09% to 52.90%. The increased flexibility resulted in reduced particle size and increased exposure of hydrophobic groups. The improved amphiphilicity of WPI provided more binding sites for complexation with curcumin. Encapsulation efficiency of curcumin was increased from 32.50% to 94.48%. Interestingly, the formed complexes were able to protect curcumin from degradation with improved storage stability and bioaccessibility. Thus, PS plus PG could serve as effective modification strategy for utilization of WPI as a promising delivery vehicle for hydrophobic bioactives.
核桃蛋白分离物（WPI）的技术功能性质较差，限制了其作为载体提高姜黄素生物利用度的应用。在本研究中，通过 pH 移位（PS）和蛋白谷氨酰胺酶（PG）对 WPI 进行改性。研究了 WPI 的物理化学和结构特性的变化及其与姜黄素络合的影响。PS 加 PG 的处理增加了 WPI 的静电斥力，并改变了二级和三级结构。WPI 的溶解度从 18.09%大幅提高到 52.90%。增加的灵活性导致粒径减小，疏水性基团暴露增加。WPI 的两亲性提高，为与姜黄素络合提供了更多的结合位点。姜黄素的包封效率从 32.50%提高到 94.48%。有趣的是，形成的复合物能够保护姜黄素免受降解，提高了储存稳定性和生物利用度。因此，PS 加 PG 可以作为 WPI 的有效改性策略，用于开发用于疏水性生物活性物质的有前途的输送载体。
