Department of Food Science , University of Tennessee , 2510 River Drive , Knoxville , Tennessee 37996 , United States.
J Agric Food Chem. 2019 Jun 12;67(23):6559-6568. doi: 10.1021/acs.jafc.9b01546. Epub 2019 May 28.
To deliver lactase in milk, dispersible capsules were fabricated by anti-solvent precipitation of zein to form a zein-lactase core and a shell of low-methoxyl sugar beet pectin cross-linked by Ca, involving electrostatic, hydrophobic, hydrogen-bonding, and Ca-bridging forces. At optimal conditions, an encapsulation efficiency of 93.0% and Z-average diameter of 652.7 nm were observed, and spherical particles smaller than 200 nm were observed in scanning electron microscopy. Contrasting with complete hydrolysis within 1 week by unencapsulated lactase, 50 units/mL encapsulated lactase resulted in 33.1 and 40.0% lactose hydrolysis in whole and skim milk, respectively, after 3 weeks of storage at 4 °C. In separate in vitro digestion assays, 50 units/mL encapsulated lactase resulted in 100% lactose hydrolysis in milk, contrasting with negligible activity by free lactase. These findings suggest the potential of the studied biopolymer particles to incorporate lactase in milk, prevent lactose hydrolysis during storage, and hydrolyze lactose in milk after ingestion.
为了在牛奶中递送乳糖酶，通过玉米醇溶蛋白的反溶剂沉淀来制备可分散胶囊，以形成玉米醇溶蛋白-乳糖酶核和由 Ca 交联的低甲氧基糖甜菜果胶壳，涉及静电、疏水、氢键和 Ca 桥接作用。在最佳条件下，观察到包封效率为 93.0%，Z 均直径为 652.7nm，扫描电子显微镜观察到小于 200nm 的球形颗粒。与未包封的乳糖酶在 1 周内完全水解形成对比，在 4°C 下储存 3 周后，50 个单位/mL 的包封乳糖酶分别导致全脂和脱脂牛奶中乳糖的水解率为 33.1%和 40.0%。在单独的体外消化测定中，50 个单位/mL 的包封乳糖酶导致牛奶中乳糖的水解率达到 100%，而游离乳糖酶的活性可以忽略不计。这些发现表明，所研究的生物聚合物颗粒具有在牛奶中包封乳糖酶、防止储存过程中乳糖水解以及在摄入后水解牛奶中乳糖的潜力。
