食品中很多亲脂性活性成分具有良好的保健作用，但低水平的口服生物利用度，使其生物活性的发挥受到很大限制。姜黄素作为代表性的食品亲脂性活性成分，前期研究表明其口服生物利用度与周围食品基质的组成与结构有关。本项目通过多种体外模型，系统研究食品中主要组分的种类、含量以及结构组织对姜黄素的口服生物利用度的影响。通过改变姜黄素形态、脂滴大小、浓度、组成以及界面性质、添加蛋白质、碳水化合物、矿物质，制备不同成分与结构组成的姜黄素微乳系统，以模拟食品基质模型。利用模拟胃肠道环境与caco-2细胞模型，通过物理、化学、生物学分析，系统研究姜黄素在胃肠道环境中的化学改性、生物可接收度与吸收效率并有效地筛选影响它们的主要因子。该研究为食品基质特征对姜黄素等脂溶性活性成分口服生物利用度的影响提供广泛理论基础，填补理论空白；同时为选择保健膳食组合以及亲脂活性成分功能食品的开发提供理论支持。

Curcumin is a lipophilic bioactive molecule whose ingestion has been associated with various health-promoting effects, including a strong anti-inflammatory response. However, the potential health benefits of curcumin are currently limited because of its low and variable oral bioavailability, which has been attributed to its chemical instability, low aqueous solubility, poor absorption, and rapid metabolism. Preliminary studies show that the oral bioavailability of curcumin depends on the composition and structure of the food matrix surrounding it. The purpose of this project is to systematically study the influence of the type, amount, and structural organization of major food components on the oral bioavailability of curcumin using in vitro model. Curcumin will be incorporated into emulsions designed to simulate complex food matrices. Model food matrices with well-defined compositions and structures will be prepared: curcumin form (soluble versus crystalline); lipid droplet size, concentration, composition, and interfacial properties; protein, carbohydrate, and mineral content addition. The physicochemical fate of curcumin within a simulated GIT (mouth, stomach, small intestine) will be investigated to establish the major factors impacting its bioaccessibility. HPLC will be used to establish chemical transformations of curcumin within the GIT. A cell culture model (caco-2) will be used to establish intestinal absorption of curcumin. Model food matrices with different compositions and structures will be studied to identify the most important matrix characteristics that influence the bioaccessibility, chemical transformation, and absorption of curcumin. The significance of the proposed research is that it would provide fundamental knowledge that is currently lacking about the role of food matrix characteristics on the bioavailability of an important lipophilic food component (curcumin). Successful completion of this project would provide knowledge that could be used by nutritionists to advise food consumers on the best food combinations to consume to promote health and wellness, and by food manufacturers to design effective functional food products.

本项目按照申请计划书的既定内容，成功完成了预期的研究目标。取得的具体研究成果如下：（1）通过改变乳液形态、脂滴大小、浓度、组成以及界面性质，添加蛋白质、碳水化合物、矿物质，制备了不同成分与结构组成的食品基质模型，并对多种重要的亲脂性活性成分（多甲氧基黄酮、姜黄素、紫檀芪及类胡萝卜素）进行包埋。（2）利用模拟胃肠道环境与 caco-2 细胞模型，系统研究了不同乳液传递系统在胃肠道中的物理化学性质变化，并发现乳液传递系统包埋的脂溶性活性成分肠道内吸收机制：口腔、胃和小肠中的酶、盐离子、pH值等均会破坏乳液的稳定性；乳液中的脂质纳米颗粒，在小肠中三酰基甘油酯被分解为1分子的单酰基甘油酯和2分子的脂肪酸，同胆汁盐形成混合胶束，包裹着亲脂性活性成分穿过粘液层，到达小肠细胞表面从而吸收。（3）开展了不同成分和结构组成的乳液传递系统对亲脂性活性成分生物可接受度、生物利用度及代谢的影响研究，结果发现：乳液中的油相对亲脂性活性成分的生物可接受度和生物利用率影响显著，对于脂肪酸类，长链脂肪酸优于短链脂肪酸；不同的油脂类型（橄榄油和亚麻籽油）对亲脂性活性成分传输效果不同，橄榄油优于亚麻籽油；传递系统的成分影响其防止亲脂性活性成分姜黄素降解的能力（脂质纳米乳液≈玉米蛋白纳米悬浮液＞纳米脂质体），在提高其生物利用度方面，以纳米乳液为最好，且不同传递体系混合使用，要优于单一系统；不同油相构建的纳米乳液传递系统，影响亲脂性活性成分紫檀芪体内代谢，橄榄油传递系统中紫檀芪II相代谢产物显著少于亚麻籽油传递系统，由于代谢产物与原型化合物生物活性不同，因此油相组成会进一步影响其生理功能的发挥。该研究为食品基质特征对脂溶性活性成分口服生物利用度的影响提供广泛理论基础，为设计更有效的功能性食品、促进健康饮食提供科学指导。相关研究成果已发表论文10篇，其中SCI 9篇；申请国家专利3项，授权2项。