鱼皮明胶-海藻酸钠相行为调控的BITC乳液输送系统稳态化及控释机制研究

Protein/polysaccharide mixtures phase behaviors determine the stability and release characteristics of foods emulsion-based delivery systems. Our previous studies have fabricated the emulsion of fish skin gelatin (FSG)-benzyl isothiocyanate (BITC), which appeared to be stable. However, the controlled release of BITC in emulsion did not realized which limited the popularization and application of this emulsion. FSG-alginate (Alg) mixtures as carrier of lipophilic nutrients and BITC as active ingredient fabricate emulsion-based delivery system, nevertheless, how to regulate the phase behaviors of FSG-Alg mixtures to insure emulsion system stabilizing properties? What kind of controlled release mechanism of BITC is in the emulsion system? The answers of these questions remain uncertain. Therefore, this project will manipulate FSG-Alg compound behavior on stability mechanism of emulsion-based delivery system by analyzing the phase behaviors, conformational transition of FSG-Alg mixtures and emulsion characterization. The interfacial properties variations of emulsion-based delivery system at different stages of gastric and intestinal digestion will be studied through the multi-level GIT model. Simulated in vitro release and absorption mechanism at cellular level and in animals of BITC in emulsion-based delivery system will be evaluated by using the model of diffusion, Caco-2 cells as well as rat situ single-pass intestinal perfusion, and the controlled release mechanism of BITC will be finally clarified. The project aims to establish the longitudinal correlation between of compound device phase behaviors, interfacial properties and controlled release capability of emulsion-based delivery system. Consequently, the studies of this project will provide scientific theory-bases on the development of protein/polysaccharide mixtures in emulsion-based delivery systems.

蛋白质-多糖复合载体相行为可决定食品乳液输送系统的稳定性及释放特性。申请人前期构筑的鱼皮明胶（FSG）-异硫氰酸苄酯（BITC）乳液，具有较好的稳定性，但未能实现对BITC的可控释放，限制了其进一步推广应用。而以鱼皮明胶-海藻酸钠（Alg）作为复合载体构筑的BITC乳液输送系统，其相行为调控乳液输送系统稳态化及其控释机制尚不明确。因此，本项目拟通过对复合载体相行为、构象变化及乳液特征的整合分析，明确调控FSG-Alg相行为的乳液系统稳定机制；通过多级GIT模型，明确不同消化阶段乳液界面性质的变化规律；通过扩散模型、Caco-2细胞模型和大鼠肠灌注模型，明确乳液输送系统中BITC的释放特性及其在细胞和动物水平的吸收特性，最终阐明乳液输送系统中BITC的控释机制，建立“复合载体相行为-乳液界面特性-乳液控释能力”的纵向关联，为蛋白质-多糖复合载体乳液输送系统的发展提供科学理论依据。

以提高脂溶性活性物质在乳液输送系统中的稳定性与生物利用率为出发点，以扩大海洋源蛋白在食品领域中的应用范围为主要目的，申请人前期构筑的鱼皮明胶（FSG）-异硫氰酸苄酯（BITC）乳液具有较好的稳定性，但未能实现对BITC的可控释放，限制了其进一步推广应用。蛋白质-多糖复合载体相行为可决定食品乳液输送系统的稳定性及释放特性，本项目以鱼皮明胶-海藻酸钠（Alg）作为复合载体构筑BITC乳液输送系统，首先综合运用热力学、光谱学、界面力学、显微成像技术等研究手段解析FSG与Alg结合的相互作用力，揭示FSG与Alg复合体系的相行为及相互作用规律，明确调控FSG-Alg相行为的作用力为静电作用，FSG和Alg的复配比为4:1时二者结合度最高，复合体系的乳化性最佳，适合作为壁材进行乳液体系的制备；在此构筑条件下，FSG-Alg复合乳液输送系统具有更好的贮藏稳定性以及环境压力耐受稳定性；其次，基于多级GIT体外模拟消化模型，对FSG-Alg复合乳液输送系统界面性质、壳核结构、乳液特性进行解析，发现在消化期间Alg的存在避免了酶或胆盐直接接触到FSG或油相表面，Alg的丝状结构使复合乳液输送系统空间结构更加完整，对BITC的保护能力显著优于FSG乳液输送系统,可以起到更好的缓释作用；最后，基于大鼠外翻肠囊模型、大鼠肠灌注模型和小鼠动物模型，结合色谱技术等手段，明确了FSG-Alg复合乳液输送系统中BITC的释放特性和肠道吸收特性，结果表明，FSG-Alg复合乳液输送系统促使包埋在油相中的BITC尽可能多的被释放到胶束相中，提高了BITC的生物利用度及肠道细胞的转运能力，十二指肠的BITC吸收率最高。本项目不仅丰富了乳液复合载体的结构设计，也为蛋白质-多糖复合载体乳液输送系统的功能调控机制研究提供科学理论依据。