Improvement of functional properties of egg white proteins through phosphorylation by dry-heating in the presence of phosphate.

通过在磷酸盐存在下干热进行磷酸化，改善蛋清蛋白的功能特性。

基本信息

批准号：
14560226
负责人：
AOKI Takayoshi
金额：
$ 2.3万
依托单位：
Kagoshima University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2002
资助国家：
日本
起止时间：
2002 至 2004
项目状态：
已结题

项目摘要

Protein phosphorylation has been used to improve the functional properties of food proteins. Furthermore, it is possible to make a functional protein enhancing calcium absorption. Recently, as the roles of phosphate groups in physiological and immune function have been reported, it is expected that these functional properties of protein also could be added by phosphorylation. Therefore, EWP was phosphorylated by dry-heating in the presence of orthophosphate or pyrophosphate(PP). The phosphorus content of EWP was 1.05% when it was dry-heated at pH 4.0 and 85℃ for 5 days in the presence of PP, which was higher than that of casein. The electrophoretic mobility of EWP depended on the phosphorylation level. The introduced phosphate bonds were stable at pH 2-10. The results from ^<31>P NMR and dephosphorylation of PP-phosphorylated proteins by treatment with enzyme, acid or alkaline also supported the existence of the N-P bond. The emulsifying activity and emulsion stability were increased by phosphorylation. The digestibility of PP-EWP was increased, and the calcium phosphate-solubilizing ability of EWP was given by phosphorylation. Even being heated at 95℃ for 10 min, the soluble protein was more than 95% in 0.1% PP-EWP solution (pH 7.0), suggesting significantly improved heat stability. Furthermore, the gelling properties of PP-EWP were improved, and a transparent and firmer heat-induced gel with better water hold-capacity was obtained. It is expected that PP-EWP may enhances calcium absorption in small intestine because it solubilized calcium phosphate.In conclusion, phosphorylation by dry-heating in the presence of pyrophosphate is an effective method to improve the functional properties of EWP

蛋白质磷酸化已被用来改善食品蛋白质的功能特性，此外，最近，随着磷酸基团在生理和免疫功能中的作用的报道，人们期望这些功能蛋白质能够增强钙的吸收。蛋白质的功能特性也可以通过磷酸化来实现，因此，在正磷酸盐或焦磷酸盐(PP)存在下，将EWP进行干热磷酸化，此时EWP的磷含量为1.05%。在 PP 存在下，在 pH 4.0 和 85℃ 下干热 5 天，EWP 的电泳迁移率取决于引入的磷酸键，结果在 pH 2-10 下稳定。来自 31 P NMR和通过用酶、酸或碱处理的PP-磷酸化蛋白质的去磷酸化也支持N-P键的存在。磷酸化提高了PP-EWP的乳化活性和乳化稳定性，磷酸化赋予了EWP溶解磷酸钙的能力，即使在95℃下加热10min，可溶性蛋白仍大于95。 % 在 0.1% PP-EWP 溶液（pH 7.0）中，表明热稳定性显着提高，此外，PP-EWP 的胶凝性能也得到改善。 PP-EWP 可以溶解磷酸钙，从而获得透明且更坚固的热诱导凝胶，具有更好的持水能力，因此预计 PP-EWP 可以增强小肠中的钙吸收。焦磷酸盐是改善EWP功能特性的有效方法