Abstract To improve the stability of zein core-shell structure microcapsule and realize intestine-specific release of lipophilic bioactive compounds, the β-carotene-loaded microcapsule was prepared by zein cross-linked with citric acid (CA) for the first time. The antioxidant activity of β-carotene was not affected by preparation process. Compared to uncross-linked microcapsule (UCM), the CA cross-linked microcapsule (CCM) had higher β-carotene encapsulation efficiency (94.4% vs. 91.4%), greater shell thickness (161 nm vs. 140 nm) and denser shell structure. Additionally, the CCM had better stability under thermal, freeze-thaw and ionic strength treatments. The fourier transform infrared spectra (FTIR) and circular dichroism (CD) analysis showed that there existed hydrogen bonding and interactions between zein and CA, and differential scanning calorimetry (DSC) and X-ray diffraction (XRD) data revealed the thermal stability and crystallinity intensity of zein/CA complex were improved. The CCM was more stable in simulated gastric fluids and β-carotene bioaccessibility was significantly improved in simulated intestine fluids (72.4% vs. 48.5%).

中文翻译：

---

柠檬酸交联玉米蛋白微胶囊作为亲脂性生物活性化合物的高效肠道特异性口服给药系统

摘要 为提高玉米醇溶蛋白核壳结构微胶囊的稳定性，实现亲脂性生物活性化合物的肠道特异性释放，首次将玉米醇溶蛋白与柠檬酸（CA）交联制备了负载β-胡萝卜素的微胶囊。β-胡萝卜素的抗氧化活性不受制备工艺的影响。与未交联微胶囊 (UCM) 相比，CA 交联微胶囊 (CCM) 具有更高的 β-胡萝卜素包封效率（94.4% 对 91.4%）、更大的壳厚度（161 nm 对 140 nm）和更致密的壳结构. 此外，CCM 在热、冻融和离子强度处理下具有更好的稳定性。傅里叶变换红外光谱（FTIR）和圆二色性（CD）分析表明玉米醇溶蛋白与CA之间存在氢键和相互作用，差示扫描量热法 (DSC) 和 X 射线衍射 (XRD) 数据表明玉米醇溶蛋白/CA 复合物的热稳定性和结晶度强度有所提高。CCM 在模拟胃液中更稳定，β-胡萝卜素生物可及性在模拟肠液中显着提高（72.4% 对 48.5%）。