中文摘要：

为探究鳕鱼骨明胶多肽螯合钙的较佳制备工艺及其消化吸收稳定性,以螯合率为指标对鳕鱼骨明胶多肽与CaCl2的螯合工艺进行了优化,并利用体外胃肠模拟消化系统考察了产物在胃肠道环境中螯合率的变化情况。通过Box-Behnken试验设计与响应面分析,优化后螯合工艺确定为酶解时间1.5h、肽钙质量比8∶1、pH5.5、螯合温度50℃、螯合时间1h,最终螯合率可达93.47%。扫描电子显微镜结果显示,鳕鱼骨明胶多肽与Ca^2＋螯合后由粗糙的纤维状结构变为光滑的球状颗粒;傅里叶变换红外光谱显示Ca^2＋和鱼骨明胶肽的氨基端与羧基端相结合。体外模拟消化实验证明,钙肽螯合物在模拟胃液中结构易受破坏,螯合率从60.74%降低到3.64%;在模拟肠液中螯合率随着时间的延长,由10.74%上升至53.38%（120 min）。研究结果为水产加工副产物的高值化利用及鱼骨明胶多肽螯合钙这一新型补钙制剂的开发提供了理论支持与技术参考。

英文摘要：

The preparation and digestion stability of calcium-chelated cod bone gelatin peptides were investigated in this study.The optimal parameters for chelating cod bone gelatin polypeptides with CaCl2 were obtained by using a 3-factor 3-level Box-Behnken experimental design with response surface methodology as follows： after the gelatin was hydrolyzed at 50 ℃ for 1.5 h,the hydrolysate and CaCl2 were mixed at 50 ℃ at a mass ratio of 8：1 for 1 h and adjusted to pH 5.5.Then,after reaction,the samples were collected by precipitating the calcium-chelated cod bone gelatin polypeptides with pure ethanol,and dehydrated by vacuum freeze drying.The chelating rate was 93.47%.Scanning electron microscope showed that the microstructure of cod bone gelatin polypeptides changed dramatically after chelated with Ca^2＋,turning from coarse fibers into smooth spherical granules.Fourier transform infrared spectroscopy analysis suggested that after chelated with Ca^2＋,the spectra of gelatin peptides and its calcium-chelated form changed dramatically,indicating the occurrence of chelating reaction between gelatin peptides and Ca^2＋.The calcium chelating rate of cod bone gelatin polypeptides decreased from 60.74% to 3.64% after simulated gastric digestion（p H 2.0） for 120 min because H^＋ competed for the binding sites with Ca^2＋,causing damage to the calcium-chelated form.The chelating rate increased from 10.74% to 53.38% after 120 min simulated intestinal digestion.However,there was almost 50% of free Ca^2＋ in the system,suggesting that the chelated structure is sensitive to the gastric environment but remains relatively stable in the intestinal system.The results of this study can provide theoretical support and technical reference for the development of new calcium supplements and for the high-value utilization of aquatic product processing byproducts.