Microfluidics is characterized by the manipulation of fluids in submillimeter channels and has great application potential in encapsulation. To further extend the application of microfluidics in food industries, a 3D printed microfluidic device is used to encapsulate vitamin A and improve its stability. Two natural macromolecules, sodium alginate and gelatin, are added to water as the continuous phase to generate monodisperse emulsion. Under different flow rate ratios, the diameter of droplets decreases with the increase of continuous flow rate. However, at the same flow rate ratio, varying the dispersed and continuous flow rates does not significantly change the diameter and size distribution of emulsion collected. The prepared O/W (oil/water) single emulsion can form microgel particles and avoid degradation of vitamin A by simulated gastric acid; the encapsulated vitamin A will not be released until particles reach simulated intestinal tract. In the simulated digestion in vitro, no vitamin A is released for 2 h in the acidic environment; under an alkaline or neutral environment such as those in intestinal fluids, vitamin A can be released from the microgel particles within 2.5 h. Using the presented approach, emulsions encapsulating vitamin A have been prepared and can potentially be applied to encapsulate other oil-soluble substances in the food industry.

微流体的特点是在亚毫米通道中操纵流体，在封装方面具有巨大的应用潜力。为了进一步扩展微流控技术在食品行业的应用，采用 3D 打印微流控装置封装维生素 A 并提高其稳定性。将两种天然大分子海藻酸钠和明胶作为连续相加入水中，生成单分散乳液。在不同的流量比下，液滴的直径随着连续流量的增加而减小。然而，在相同的流速比下，改变分散和连续流速不会显着改变所收集乳液的直径和尺寸分布。制备的O/W（油/水）单乳剂可形成微凝胶颗粒，避免维生素A被模拟胃酸降解；在颗粒到达模拟肠道之前，包裹的维生素 A 不会被释放。在体外模拟消化中，在酸性环境下2h不释放维生素A；在碱性或中性环境（如肠液）下，维生素A可在2.5小时内从微凝胶颗粒中释放出来。使用所提出的方法，已经制备了包裹维生素 A 的乳液，并且有可能应用于包裹食品工业中的其他油溶性物质。