疏水化β-葡聚糖自组装纳米水凝胶对亲脂性多酚的增溶及控释机制

The role of the interaction between polyphenols and polysaccharides in controlling flavour, texture, nutritional and functional qualities of foods attracted much attention in recent years. Unlike the lucubrated study on the interactions between polyphenols and proteins, the study on the interactions between polyphenols and polysaccharides is scant and their influencing mechanism on foods is still remain in secret. Based on our previous researches on the interaction between β-glucan and hydrophilic polyphenols (tea polyphenols), this study was designed to investigate the solution behavior of hydrophobic β-glucan and its interaction with the lipophilic polyphenols. The key aim of this work was to elucidate the molecular mechanisms of solubilization and colon-targeted control release of hydrophobic polyphenols by self-assembly nano-scale hydrogel formed with hydrophobic β-glucan. The main research content are as follows:1) Directional construction mechanism of the self-assembly nano-scale hydrogel with hydrophobic β-glucan. 2) Structure-activity relationship and dynamics of the solubilization of lipophilic polyphenols by the nano-scale hydrogel. 3) Characterization of lipophilic polyphenol bearing nano-scale hydrogel for food application and colon-targeted control releases. This study can provide a new sight in improving food quality through the interactions of food ingredients, can offer experimental evidence to the changes of the existing form and behavior of polysaccharides and polyphenols in foods, and is valuable in the development of innovative food additives and efficient utilization of functional food components.

最近多酚-多糖的相互作用在调控食品风味、质地、营养及功能方面的作用得到极大重视。与多酚-蛋白质相互作用已得到深入研究不同，多酚-多糖相互作用的研究极为薄弱，其对食品的影响及作用机制尚不明确。本研究在对水溶性β-葡聚糖与亲水性多酚相互作用的前期研究基础上，开展疏水化β-葡聚糖与亲脂性多酚的相互作用，重点以阐明疏水化β-葡聚糖自组装纳米水凝胶对亲脂性多酚的增溶及结肠靶向控释分子机制为目标，主要进行如下研究：1）纳米级疏水化β-葡聚糖自组装水凝胶定向构建机制；2）疏水化β-葡聚糖自组装纳米水凝胶对亲脂性多酚增溶的构效关系及动力学；3）荷载亲脂性多酚疏水化β-葡聚糖纳米水凝胶的食品应用特性及肠道控释行为。该研究能为明确食品成分间的相互作用并对食品品质的有效调控提供新的视角；为食品中多糖与多酚的形态及行为变化提供实验证据；同时对开发新型食品添加剂及食品功能成分的高效利用技术与方法具有重要的参考价值。

本项目研究了OS-燕麦β-葡聚糖酯(OS-β-GE)胶束与亲脂性多酚的相互作用，并就荷载多酚的OS-β-GE胶束的稳定性、靶向性及生物利用率进行研究，获得如下研究结论和成果：. (1) 反应条件对OS-β-GE的取代度有显著影响。当反应时间4.66 h，反应温度45.6 ℃，OS-β-G浓度2.18 mg/mL时合成的产物的取代度最高。. (2) OS-β-GE结构及环境因素对其自聚集行为有重要影响。不同取代度和重均分子质量的OS-β-GE的临界胶束浓度（CMC）和胶束粒径分为0.206~0.039 mg/mL 和175~600 nm。胶束呈球形且表面带负电荷。随取代度升高，OS-β-GE的CMC随之降低。外部环境因素(pH、温度、离子强度和聚合物浓度)对其自聚集行为也会产生显著影响，但规律各不一样。. (3) OS-β-GE结构及操作条件对其荷载姜黄素的量有明显影响。随OS-β-GE取代度增加，姜黄素荷载量先升高后降低；随着OS-β-GE重均分子质量增加，姜黄素荷载量逐渐升高。取代度为0.0199和重均分子质量为1.68×105 g/mol的OS-β-GE具有最大姜黄素荷载量(4.21μg/mg)。姜黄素荷载量随输入功率的提高而增大，且明显依赖于聚合物浓度、环境pH和温度等因素。当在输入功率4.4 W，温度35.7 ℃，pH5.9，OS-β-GE浓度2.57 mg/mL，搅拌96 h时可获得最大姜黄素荷载量（21.16 µg/mL）。姜黄素以无定形态荷载于OS-β-GE颗粒中。. (4) 亲脂性多酚的结构对其在OS-β-GE胶束中的增溶影响显著。类黄酮和香豆酸异构体在OS-β-GE胶束中的荷载量顺序为：黄酮醇>黄酮>异黄酮>黄烷酮和邻位香豆酸>间位香豆酸>对位香豆酸。没食子酰化使EC和EGC的荷载量显著降低。. (5) 荷载姜黄素的OS-β-GE胶束具有良好的食品加工稳定性和结肠靶向性。OS-β-GE胶束能显著提高姜黄素对可见光、紫外线和热的稳定性。荷载于胶束中的姜黄素在25 ℃的贮藏稳定性显著低于4 ℃时的。荷载于胶束中的姜黄素在胃与小肠中有较高的稳定性且释放缓慢，而在结肠中能快速释放，具有结肠靶向性。. (6) 本项目标注累计发表论文34篇，其中SCI收录论文18篇，国内核心期刊论文16篇；获得国家发明专利授权1项。