花生肽钙复合物钙结合特性及氨基酸组成研究

Calcium binding property and amino acid composition of peanut peptide calcium complex

利用花生分离蛋白通过酶解法制备花生肽,将花生肽脱酰胺处理,制备花生肽钙复合物。研究脱酰胺处理对花生肽钙结合量的影响,并分析花生肽钙复合物钙结合特性及氨基酸组成。结果表明:脱酰胺处理240 min后花生肽的钙结合量由82. 05 mg/g显著增加到135. 26 mg/g,表明脱酰胺处理可以显著提高花生肽的钙结合量;扫描电镜分析结果表明加钙反应后花生肽微观结构发生明显变化,由疏松片状结构聚合为颗粒状结构;傅里叶红外光谱分析结果表明花生肽肽链上的氨基及羧基是钙离子的主要结合位点,经脱酰胺处理羧基伸缩振动带进一步发生移动,表明脱酰胺后羧基上的氧原子与钙的配位作用得到增强,促进了花生肽钙结合量的提高;花生肽钙复合物中天冬氨酸含量为10. 76%,谷氨酸含量为23. 49%,表明酸性氨基酸含量是花生肽具有高钙结合量的重要因素。

Peanut peptide was prepared by enzymatic hydrolysis of peanut protein isolate.The peanut peptide calcium complex was prepared by deamidation of peanut peptide.The effect of deamidation on the calcium binding capacity of peanut peptide was studied,and the calcium binding property and amino acid composition of peanut peptide calcium complex were analyzed.The results showed that the calcium binding capacity of peanut peptide after deamidation for 240 min significantly increased from 82.05 mg/g to 135.26 mg/g,indicating that the deamidation treatment could significantly increase the calcium binding capacity of peanut peptide.The results of scanning electron microscopy showed that the microstructure of peanut peptide changed significantly after calcium addition,and it was polymerized into granular structure by loose sheet structure.The results of Fourier transform infrared spectroscopy showed that the amino and carboxyl groups on the peanut peptide chain were the main calcium binding site,after the deamidation treatment,the carboxyl group stretching vibration band further moved,indicating that the coordination of the oxygen atom on the carboxyl group and the calcium was enhanced after deamidation,which promoted the increase of the calcium binding capacity of the peanut peptide.The content of aspartic acid in peanut peptide calcium complex was 10.76%,and the content of glutamic acid was 23.49%,indicating that the acidic amino acid content was an important factor for high calcium binding capacity of peanut peptide.