双亲性淀粉胶束运载多不饱和脂肪酸体系构建及消化机制

EPA, DHA and DPA are important polyunsaturated fatty acids (PUFA) that are widely found in deep-sea fish oils and algae oils. They play an outstanding role in lowering serum triacylglycerols, anti-cancer, anti-inflammatory, and promoting growth and development, etc. However, the extremely susceptible to oxidation due to the high degree of unsaturation and poor solubility in the aqueous phase resulting in their low bioavailability. Privious study has found that the octenyl succinic anhydride- modified short glucans (OSA-SGC) can spontaneously form micelles and have potential applications for delivering hydrophobic active ingredients. In this project, we intend to obtain a PUFA loaded nanocarrier system by incorporating PUFA into the OSA-SGC self-aggragated micelles. The effect of molecular characteristics, component concentration and proportion on the loading capacity and the oxidative stability of PUFA would be systematically investigated by using DLS, SEM, TEM, FTIR and other technical analysis methods in order to reveal the formation mechanism of PUFA-OSA-SGC micelles; Experiments will be conducted to simulate in vitro gastrointestinal digestion in order to investigate the effects of OSA-SGC and PUFA molecular properties and their interactions on the digestibility of PUFA, and to explain the digestion behaviour of the micelles; Finally, the Caco-2 monolayer cell model are to be established to study the absorption characteristics of the carrier system. The aim is to improve the oxidation stability and bioavailability of PUFA.

EPA、DHA、DPA是广泛存在于深海鱼油、藻油中的重要多不饱和脂肪酸（PUFA），在降血脂、抗癌、抗炎、促进生长发育等方面发挥突出的功效。但由于其高度不饱和性，极易发生氧化劣变，且在水相体系中溶解性差，因而生物利用度低。前期研究发现辛烯基琥珀酸酐修饰的短直链淀粉（OSA-SGC）具有自组装形成胶束的特性，可装载疏水的活性成分。本项目拟采用OSA-SGC为基质，构建PUFA-OSA-SGC纳米胶束运载体系。结合DLS、SEM、TEM、FTIR等技术手段系统研究分子特性、组分浓度和比例等对PUFA装载率、氧化稳定性的影响，揭示PUFA-OSA-SGC纳米胶束形成机理；模拟体外消化实验，探究OSA-SGC与PUFA分子特性及其相互作用对PUFA消化率的影响，阐释纳米胶束消化规律；并结合Caco-2单层细胞模型，研究该运载体系的吸收特性，旨在提高PUFA的稳定性和生物利用率。

经辛烯基琥珀酸酐疏水改性的淀粉及其衍生物在装载功能性脂质及其成分方面具有优良的性能。本项目首先以辛烯基琥珀酸改性淀粉酯（OSA淀粉）为基质，研究了其在装载富含多不饱和脂肪酸的脂质方面的应用，结合动态光散射（DLS）、傅里叶红外光谱（FT-IR）、扫描电镜（SEM）、透射电镜（TEM）、等温滴定量热仪（ITC）、耗散型石英晶体微天平（QCM）等技术手段，对OSA淀粉在稳定中性脂质乳液、制备微胶囊中的应用进行了探索，通过优化影响乳液稳定性及脂质氧化稳定性的条件，确定了制备藻油乳液、微胶囊的最佳工艺参数；之后通过将传统的脂肪酸富集手段与制备液相色谱相结合，研究了从海豹油中分离纯化二十二碳五烯酸（DPA）的工艺，得到纯度为90%以上的脂肪酸纯品，为后续改性淀粉稳定弱极性的脂肪酸提供基础原料；继而研究了不同来源及不同聚合度所得脱支淀粉经疏水改性后的分子组成、结构及功能性方面的差异，为构建适合于包载功能性脂质及其组分的胶束体系提供了理论基础。经研究表明，脱支不同程度的淀粉在形成淀粉胶束上具有显著差异，糯米淀粉容易形成胶束，且在形成胶束的过程中能够实现对多不饱和脂质的装载，提高脂质稳定性。本研究为进一步探究胶束中组分及胶束基质相互作用及进一步探究其消化规律奠定了坚实的工作基础，同时对于提高胶束在稳定食品功能组分方面的应用提供了重要的理论依据。项目资助期间，发表SCI 3篇，国内权威性学术期刊2篇，待发表2篇。培养硕士生2名，其中一名已经取得硕士学位，1名在读。项目资助经费23万元，支出18.5083万元，各项支出基本与预算相符。剩余4.4917万元，用于本项目的研究后续支出。