Bao Zhijie, Zhang Penglin, Sun Na, Lin Songyi
National Engineering Research Center of Seafood, School of Food Science and Technology, Dalian Polytechnic University, Dalian 116034, China.
Foods. 2021 Oct 25;10(11):2565. doi: 10.3390/foods10112565.
With the current study, we aimed to determine the characteristics and calcium absorption capacity of egg white peptide-calcium complex (EWP-Ca) and determine the effect of sterilization on EWP-Ca to study the possibility of EWP-Ca as a new potential calcium supplement. The results of SEM and EDS showed a high calcium chelating ability between EWP and calcium, and the structure of EWP-Ca was clustered spherical particles due its combination with calcium. The FTIR and Raman spectrum results showed that EWP could chelate with calcium by carboxyl, phosphate, and amino groups, and peptide bonds may also participate in peptide-calcium binding. Moreover, the calcium absorption of EWP-Ca measured by the intestinal everted sac model in rats was 32.38 ± 6.83 μg/mL, significantly higher than the sample with CaCl and the mixture of EWP and Ca ( 0.05) revealed appropriate calcium absorption capacity. The fluorescence spectra and CD spectra showed that sterilization caused a decrease in the content of α-helix and β-sheet and a significant increase in β-turn ( 0.05). Sterilization changed the EWP-Ca structure and decreased its stability; the calcium-binding capacity of EWP-Ca after sterilization was decreased to 41.19% ( 0.05). Overall, these findings showed that EWP could bind with calcium, form a peptide-calcium chelate, and serve as novel carriers for calcium supplements.
在本研究中，我们旨在确定蛋清肽 - 钙复合物（EWP-Ca）的特性和钙吸收能力，并确定杀菌对EWP-Ca的影响，以研究EWP-Ca作为一种新型潜在钙补充剂的可能性。扫描电子显微镜（SEM）和能谱分析（EDS）结果表明，EWP与钙之间具有较高的钙螯合能力，并且由于EWP与钙的结合，EWP-Ca的结构为聚集的球形颗粒。傅里叶变换红外光谱（FTIR）和拉曼光谱结果表明，EWP可通过羧基、磷酸基团和氨基与钙螯合，肽键也可能参与肽 - 钙的结合。此外，通过大鼠肠外翻囊模型测得的EWP-Ca的钙吸收量为32.38±6.83μg/mL，显著高于氯化钙样品以及EWP与钙的混合物（P<0.05），表明其具有适当的钙吸收能力。荧光光谱和圆二色光谱（CD）表明，杀菌导致α-螺旋和β-折叠含量降低，β-转角显著增加（P<0.05）。杀菌改变了EWP-Ca的结构并降低了其稳定性；杀菌后EWP-Ca的钙结合能力降至41.19%（P<0.05）。总体而言，这些发现表明EWP可以与钙结合，形成肽 - 钙螯合物，并作为钙补充剂的新型载体。
