玉米肽螯合钙纳米粒的制备及结构表征分析

Preparation and Structural Characterization of Corn Peptide Chelated Calcium Nanoparticles

为了探明玉米肽与钙离子螯合纳米粒的结构与特性,以小分子玉米肽(CPT)为钙离子螯合载体,采用有机溶剂沉淀法制备玉米肽纳米螯合钙(CPT-Ca)复合纳米粒,研究了其制备工艺、结构表征及体外抗氧化活性。结果表明,玉米肽螯合钙(CPT-Ca)的最佳制备条件为:玉米肽与氯化钙质量比40∶1,pH 7.0,螯合时间为60 min,温度为50℃,此条件下肽钙螯合率为(81.20±3.55)%。该螯合钙粒子的平均粒径为(396.0±8.0)nm,多分散系数为0.043,Zeta电位为(-22.6±0.7)mV,具有良好的纳米粒子微观结构特性;傅里叶红外光谱(FTIR)、紫外吸收光谱(UV)和X射线衍射图谱(XRD)显示,玉米肽上的氨基与羧基提供结合位点以配位键方式与钙离子结合,形成新的肽-钙螯合物;抗氧化实验表明,螯合钙具有较好的羟基和DPPH自由基清除自由基能力。玉米肽螯合钙纳米粒对于改善钙离子的结构分布和体内外传递吸收,开发新型玉米肽功能食品与钙离子补充剂具有重要作用。

In order to reveal the structure and properties of corn peptide chelated calcium nanoparticles,the small molecule corn peptide(CPT)was used as a calcium ion carrier and corn peptide nano chelated calcium composite nanoparticles(CPT-Ca)were prepared by organic solvent precipitation method.The preparation process,structural characterization,and in vitro antioxidant activity of CPT-Ca were studied.The results indicated that the optimal preparation conditions of CPT-Ca were as follows:the mass ratio of corn peptide to calcium chloride was 40∶1,pH value was 7.0,chelation time was 60 minutes,temperature was 50℃,and the chelation rate of calcium peptide was(81.20±3.55)%under these conditions.The average particle size of the nano chelated calcium was(396.0±8.0)nm,the polydispersity coefficient was 0.043,and the Zeta potential was(-22.6±0.7)mV,exhibiting excellent nanoscale microstructure characteristics;Fourier transform infrared spectroscopy(FTIR),ultraviolet absorption spectroscopy(UV)and X-ray diffraction(XRD)revealed that the amino and carboxyl groups on the corn peptide provided a binding site to bind with calcium ions in the way of coordinate covalent bond,forming a new peptide calcium chelation;antioxidant experiments indicated that CPT-Ca had good hydroxyl and DPPH free radical scavenging ability.Corn peptide chelated calcium nanoparticles play an important role in improving the structural distribution and in vivo and in vitro transmission and absorption of calcium ions,and in developing new corn peptide functional foods and calcium ion supplements.