两种酪蛋白磷酸肽阻止钙沉淀形成的比较研究

A Comparative Study on the Prevention of Calcium Precipitation by Two Types of Casein Phosphopeptides

摘要:

酪蛋白磷酸肽（casein phosphopeptides，CPP）是以牛乳酪蛋白为原料，含有成簇的磷酸丝氨酸的生物活性肽。本文通过比较两种不同氮磷摩尔比（N/P）的CPP样品抑制钙离子形成沉淀的功能以及pH值、温度和CPP浓度对其的影响，并与柠檬酸和木糖醇的协同作用进行比较研究。结果表明：CPP浓度是CPP作用效果的主要影响因素，pH值对CPP影响较大，其次是柠檬酸和木糖醇的添加。温度对CPP作用效果几乎没有影响；柠檬酸和木糖醇与两种CPP之间都有一定的协同作用并且两种CPP与柠檬酸的协同作用效果接近。且浓度越高，效果越好。在抑制金属离子沉淀，pH、CPP浓度和木糖醇协同作用上CPPⅡ的作用效果较好，但温度对其两者都没有影响。两种CPP样品都具有良好的功能性质，但氮磷摩尔比（N/P）低的CPPⅡ性质更优。本试验为我国研究开发富含CPP的功能性食品以及营养保健食品提供理论基础。

Abstract:

Casein phosphopeptides (CPPs) are biologically active peptides derived from milk casein that contain phosphoserine clusters. The ability of two CPP samples with different nitrogen/phosphorus (N/P) molar ratios to inhibit precipitation induced by calcium ions was compared, and the effect of pH, temperature, and CPP concentration on the inhibition, and synergistic effects of CPPs with citric acid and xylitol were assessed. The results show that the CPP concentration was the main influencing factor of CPP effectiveness, with pH having the largest effect on CPP, followed by addition of citric acid and xylitol. Temperature had nearly no effect on CPP activity; citric acid and xylitol had a certain synergistic effect on the two types of CPPs, and the synergistic effects of citric acid with the two types of CPPs were similar; effectiveness increased with increasing concentration. With respect to inhibition of metal ion precipitation, pH, CPP concentration, and xylitol synergism had better effectiveness on CPP II activity, but temperature had no effect on either of the CPPs. Both the types of CPPs had good functional properties, but CPP II, which had a lower N/P molar ratio, was better. This study provided a theoretical basis for research and development of CPP-rich functional and nutritional health foods in China.