Abstract Calcium ions (Ca2+) can alter the molecular structure of proteins and polysaccharides through electrostatically binding to negatively charged groups. In this study, the zein-propylene glycol alginate (PGA)-tea saponin (TS) ternary complex particles induced by different Ca2+ levels (1–10 mM) were fabricated and characterized for the delivery of resveratrol. Fluorescence spectrum and circular dichroism analysis were applied to investigate the effect of Ca2+ on the micro-environment and secondary structure of zein in the complex particles. The hydrogen bonds, hydrophobic effects and electrostatic interactions contributed to the formation of the complex particles. Environmental stability evaluation showed that the stability of the complex particles and retention rate of resveratrol were enhanced by the addition of Ca2+ at the lower concentration (≤4 mM). Besides, the level of Ca2+ could modulate the digestion behavior of the complex particles and achieve the better sustained-release of resveratrol at the Ca2+ level of 2 mM. However, the aggregation of complex particles occurred through bridging flocculation induced by the high level of Ca2+ (>6 mM). These results indicated that Ca2+ induction has a great potential for the fabrication and application of food-grade complex particles loaded with nutraceuticals.

中文翻译：

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钙离子对玉米醇溶蛋白-海藻酸丙二醇酯-茶皂素三元复合颗粒的稳定性、微观结构和体外消化命运的影响，用于递送白藜芦醇

摘要 钙离子 (Ca2+) 可以通过与带负电荷的基团静电结合来改变蛋白质和多糖的分子结构。在这项研究中，由不同 Ca2+ 水平（1-10 mM）诱导的玉米醇溶蛋白-丙二醇藻酸盐 (PGA)-茶皂素 (TS) 三元复合颗粒被制造并表征为白藜芦醇的递送。应用荧光光谱和圆二色性分析研究Ca2+对复合颗粒中玉米蛋白微环境和二级结构的影响。氢键、疏水作用和静电相互作用促成了复杂颗粒的形成。环境稳定性评价表明，加入较低浓度（≤4 mM）的Ca2+可提高复合颗粒的稳定性和白藜芦醇的保留率。此外，Ca2+ 的水平可以调节复合颗粒的消化行为，并在 2 mM 的 Ca2+ 水平下实现更好的白藜芦醇缓释。然而，复杂颗粒的聚集是通过高水平 Ca2+ (>6 mM) 诱导的桥接絮凝发生的。这些结果表明，Ca2+ 诱导在制备和应用负载营养食品的食品级复合颗粒方面具有​​巨大潜力。复杂颗粒的聚集是通过高水平 Ca2+ (>6 mM) 诱导的桥接絮凝发生的。这些结果表明，Ca2+ 诱导在制备和应用负载营养食品的食品级复合颗粒方面具有​​巨大潜力。复杂颗粒的聚集是通过高水平 Ca2+ (>6 mM) 诱导的桥接絮凝发生的。这些结果表明，Ca2+ 诱导在制备和应用负载营养食品的食品级复合颗粒方面具有​​巨大潜力。