为减少绿豆淀粉生产过程中严重的生态环境污染和蛋白质资源浪费,合成了绿豆肽-钙螯合物(MBP-Ca)作为一种新型高效的钙补充剂。在最佳条件下(pH=6,温度=45°C,绿豆肽质量比(MBP)/CaCl2=4:1,MBP浓度=20mg/mL,时间=60分钟),所得MBP-Ca的钙螯合率为86.26%。MBP-Ca,与MBP不同,是一种富含谷氨酸(32.74%)和天冬氨酸(15.10%)的新化合物。钙离子主要通过羧基氧与MBP结合,羰基氧,和氨基氮原子形成MBP-Ca。钙离子诱导的分子内和分子间相互作用导致MBP的折叠和聚集。钙离子与MBP螯合反应后,β-折叠在MBP二级结构中的百分比增加了1.90%,肽的大小增加了124.42nm,MBP致密光滑的表面结构转化为破碎的粗块。在不同的温度下,pH值,和胃肠模拟消化条件,与常规钙补充剂CaCl2相比,MBP-Ca显示出增加的钙释放速率。总的来说,MBP-Ca有望作为一种替代的膳食钙补充剂,具有良好的钙吸收和生物利用度。
To reduce grievous ecological environment pollution and protein resource waste during mung bean starch production, mung bean peptides-calcium chelate (MBP-Ca) was synthesized as a novel and efficient calcium supplement. Under the optimal conditions (pH = 6, temperature = 45 °C, mass ratio of mung bean peptides (MBP)/CaCl2 = 4:1, MBP concentration = 20 mg/mL, time = 60 min), the obtained MBP-Ca achieved a calcium chelating rate of 86.26%. MBP-Ca, different from MBP, was a new compound rich in glutamic acid (32.74%) and aspartic acid (15.10%). Calcium ions could bind to MBP mainly through carboxyl oxygen, carbonyl oxygen, and amino nitrogen atoms to form MBP-Ca. Calcium ions-induced intra- and intermolecular interactions caused the folding and aggregation of MBP. After the chelation reaction between calcium ions and MBP, the percentage of β-sheet in the secondary structure of MBP increased by 1.90%, the size of the peptides increased by 124.42 nm, and the dense and smooth surface structure of MBP was transformed into fragmented and coarse blocks. Under different temperatures, pH, and gastrointestinal simulated digestion conditions, MBP-Ca exhibited an increased calcium release rate compared with the conventional calcium supplement CaCl2. Overall, MBP-Ca showed promise as an alternative dietary calcium supplement with good calcium absorption and bioavailability.