School of Chemical and Environmental Engineering, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou, Jiangsu 215123, China.
Food Funct. 2022 Jan 24;13(2):978-989. doi: 10.1039/d1fo02993b.
Microencapsulation is a promising technique to improve the bioavailability and mask the unpleasant smell of DHA oils. Yet, how the encapsulated DHA oils are 'released' and 'digested' within the gastrointestinal tract (GIT) and the effect of the wall material and source of DHA have been largely unknown. Here, two commercial DHA microcapsules from algae oil (A-DHA) and tuna oil (T-DHA) with 100% whey protein (WP) and 80% casein and 20% WP (C-WP) as wall materials were evaluated respectively. The release ratio was nearly linearly increased to 77.7% and 41.7% after the simulated gastric phase for T-DHA and A-DHA microcapsules, respectively. In contrast to A-DHA microcapsules for which the release of DHA approached equilibrium in the later intestinal phase, a decline in the release ratio was shown for T-DHA microcapsules perhaps due to the interaction of T-DHA with bile salts resulting in the formation of micelles. The more stable release behaviors might suggest a better performance of A-DHA coated by WP, which enables sustainable release during GIT digestion. This is supported by the better ability to resist gastric proteolysis for A-DHA microcapsules. Additionally, T-DHA (27.5%) showed a lower lipid digestibility than A-DHA (68.5%) in the end due to their structure difference. Significantly positive correlations were found for both microcapsules between DHA release ratio and protein hydrolysis. This study has provided quantitative information on the release and digestion of DHA microcapsules as influenced by the wall protein and DHA source. The findings are practically meaningful for future formulation of DHA microcapsules with controlled release rates at target sites of the GIT.
微胶囊化是一种有前途的技术，可以提高 DHA 油的生物利用度并掩盖其难闻的气味。然而，封装的 DHA 油在胃肠道（GIT）内是如何“释放”和“消化”的，以及壁材的来源和 DHA 的来源的影响在很大程度上是未知的。在这里，分别评估了来自藻类油（A-DHA）和金枪鱼油（T-DHA）的两种商业 DHA 微胶囊，其壁材分别为 100%乳清蛋白（WP）和 80%酪蛋白和 20%WP（C-WP）。模拟胃阶段后，T-DHA 和 A-DHA 微胶囊的释放率分别几乎线性增加到 77.7%和 41.7%。与 A-DHA 微胶囊不同，其在后期肠阶段 DHA 的释放接近平衡，T-DHA 微胶囊的释放率下降，这可能是由于 T-DHA 与胆汁盐相互作用导致胶束形成。更稳定的释放行为可能表明 WP 包覆的 A-DHA 具有更好的性能，这使其能够在 GIT 消化过程中持续释放。这得到了 A-DHA 微胶囊更能抵抗胃蛋白水解的支持。此外，由于结构差异，T-DHA（27.5%）的脂质消化率低于 A-DHA（68.5%）。对于两种微胶囊，DHA 的释放率与蛋白质水解之间都存在显著的正相关关系。这项研究提供了关于壁蛋白和 DHA 来源影响 DHA 微胶囊释放和消化的定量信息。这些发现对于未来在 GIT 的目标部位控制 DHA 微胶囊的释放速率的配方具有实际意义。
