高静压诱导酪蛋白胶束保护花色苷C环4位的自组装形成机制

花色苷是深色果蔬中重要的活性组分，结构中带正电的C环4位是导致其不稳定的关键靶点。酪蛋白常作为天然功能性壁材保护花色苷，但其胶束结构内部磷酸钙纳米簇团（CCP）的存在严重阻碍了与花色苷分子的充分结合。申请人前期研究发现，高静压可以诱导酪蛋白胶束形成带负电的自组装纳米颗粒。这为与带正电的花色苷结合并自组装形成保护体系提供了可能性，但具体形成机制尚不清楚。本项目提出“高静压诱导酪蛋白CCP解离（打开）→与花色苷静电相互作用（装载）→纳米颗粒重新聚集（自组装）”的科学猜想，利用钙离子结合法、光谱法和微观颗粒物性分析等方法，解析100 MPa至500 MPa高静压范围内酪蛋白胶束与花色苷相互作用的变化规律，阐明高静压诱导酪蛋白胶束保护花色苷C环4位的“打开-装载-自组装”形成机制。以期从分子层面解决现有酪蛋白与花色苷体系不稳定的关键科学问题，为提高花色苷功能性及拓展其新用途提供有效的科学依据。

Anthocyanins are important bioactive components in dark color fruits and vegetables, and the positively charged C4 position in the structure is the key target that leads to the instability of anthocyanins. Casein is often used as the natural functional wall material to protect anthocyanins, but the presence of calcium phosphate nanoclusters (CCP) in the micelles seriously hinders the full binding with anthocyanin molecules. Previous studies have found that high static pressure induced casein micelles to form negatively charged self-assembled nanoparticles. It is further speculated that the positively charged anthocyanins might be effectively combined by those nanoparticles and re-assembled to form a protective system, but the specific formation mechanism is still unclear. This project provides the hypothesis of "high pressure induced casein CCP dissociation (open) → electrostatic interaction with anthocyanins (loading) → nanoparticle re-aggregation (self-assembly)". It plans to use calcium ion dynamic binding measurements, spectroscopy methods and microscopic physical methods to analyze the potential interactions between casein micelles and anthocyanins during the high static pressure range of 100 MPa to 500 MPa. The study aims to clarify that casein micelles induced by high pressure can protect the C4 position anthocyanins based on "open-load-self-assembly" mechanism. It is expected to solve the scientific problem of the current unstable casein and anthocyanin system from the molecular level, which could provide effective scientific basis for improving the functionality of anthocyanins and expanding their new applications.