基于S/O/W技术构建钙-脂质微球的稳定、流变机理及其控释规律解析

The design of new delivery systems for food nutrients to improve the solubility, bioavailability and reduce fat content is the aim of developing the healthy food. The formation of CaCO3 loaded microparticles based on the form of solid/oil/water (S/O/W) emulsion is a promising method to increase the solubility of CaCO3, the rheological properties and deliver mineral elements. The Ca loaded microparticles may have an appreciable influence upon the stability, rheological properties and the release of nutrients in the digestive tract. The Ca loaded microparticles was fabricated by suspending CaCO3 (S phase) in the melted anhydrous milk fat, medium chain fatty acid, soybean oil dissolved with emulsifier using ultrasound. The S/O suspension was emulsified in the aqueous phase with sodium caseinate or gelatin with flaxseed gum by complex coacervation through microfluidizer. The formation rule of Ca loaded microparticles was established based on the relationship between droplet size distribution, shear rheological properties and physical stability. The effect of ultrasound on the dispersity of S/O, thermodynamic and kinetic interactions between protein and flaxseed gum, microstructure, NMR analysis, microrheology, and Brown Motion, shearing rheology and tribology were determined to obtain the mechanisms of the stability and rheologcial properties. The in vitro digestion of Ca loaded microparticles was also studied. The relationship between the formation of peptide and the interaction between Ca2+ and peptide was established. Theoretically, the research can lay the foundation for the formation of Ca loaded microparticles based on S/O/W techniques. In addition, it can also provide a new technique for designing novel healthy food delivery system.

提高营养素的溶解性、生物利用率与实现脂质替代，是健康食品发展亟需解决的难点。基于S/O/W技术构建矿物质-脂质微球，是实现脂质替代与矿物质输送的新途径。针对S/O/W钙-脂质微球提高钙溶解性、脂质流变与靶向释放的科学问题，拟以碳酸钙为S相，明胶、酪蛋白酸钠/亚麻籽胶为W相，结合超声波强化扩散S/O与微射流技术，构建S/O/W钙-脂质微球，基于微球粒径分布、流变与稳定性，探索S/O/W钙-脂质微球形成规律；结合超声对S与O相扩散，W相分子间热力学、动力学相互作用，微观结构、NMR核磁共振，布朗运动轨迹、剪切流变、微流变与摩擦学分析，探明S/O/W钙-脂质微球稳定与流变学机制；研究碳酸钙胃液转化Ca2+控释动力学，通过W相在模拟胃液中形成多肽与钙溶液结合情况，初步探讨W相消化水解多肽的促钙消化机理与脂质控释规律。本研究可望揭示构建新型S/O/W载体机理，为研制新型传递系统提供理论和技术基础。

固相营养素由于分散稳定性差，很难在食品基质中传递。因此，开发新型食品营养素传递系统载体，提高分散稳定性和生物可及性，是健康食品发展亟需解决的难点问题。基于S/O/W技术构建矿物质-脂质微球，是实现矿物质输送的新途径。本项目采用稳定性、流变学、微观结构、界面吸附特性、分子间相互作用以及体外模拟消化释放特性分析等技术手段，以碳酸钙为S相，大豆油、猪油为O相，酪蛋白酸钠、酪蛋白酸钠-明胶、酪蛋白酸钠-黄原胶、酪蛋白酸钠-明胶-黄原胶、海藻酸丙二醇酯-黄原胶为W相，构建S/O/W钙-脂质微球。发现S/O/W钙-脂质微球的稳定性和在胃中的释放规律取决于外层水相体系的影响；明胶能够通过氢键和疏水相互作用与酪蛋白酸钠二元复合形成更致密的三维网络结构且降低界面张力；黄原胶则通过更强烈的氢键和疏水相互作用与酪蛋白酸钠二元复合形成了更加致密的三维网络结构，特别是形成的丝状连接更强化了空间结构，增强了界面膜的粘弹性；在酪蛋白酸钠与明胶、黄原胶三元复合的外层水相体系中，三元混合的协同作用大于二元混合体系强度，界面张力降低且体系粘弹性增加；海藻酸丙二醇酯的加入，降低了单一黄原胶在油水界面的表面张力，改善了其乳化特性。本项目成果明确了S/O/W钙-脂质微球构建关键控制点，阐释了W相组成对其稳定性与靶向缓释规律的影响，揭示了构建新型S/O/W载体的机理，提高了碳酸钙的分散稳定性，降低了碳酸钙在胃消化阶段胃液转化钙离子的速率，减缓了对胃的刺激，为解决固相营养素输送载体的难题提供理论支持和技术基础，具有良好的应用前景。