卵黄高磷蛋白酶解和脱磷对乳化性的影响研究

Effect of Protease Digestion and Dephosphorylation on High Emulsifying Properties of Hen Egg Yolk Phosvitin

卵黄高磷蛋白被发现比别的食品蛋白质的乳化性尤其乳液稳定性高。蛋白酶和磷酸酯酶可使乳化活性和乳液稳定性明显降低;卵黄高磷蛋白的蛋白酶水解导致大肽链(高磷酸化核心区50～210个肽)和小肽链裂解(N-端1～49个肽和C-端211～217个肽);不含小肽的肽不具备优秀的乳化特性,蛋白质中一部分小肽在乳化特性中扮演着重要角色;磷酸酯酶处理后,卵黄高磷蛋白中磷酸酯的静电排斥力对乳化性有显著影响;磷酸充分作用后的残基的这部分蛋白质对高乳化特性至关重要。

The emulsifying properties, particularly the emulsion stability of phosvitin was found to be higher than those ofother food proteins. The emulsifying activity and emulsion stability were greatly decreased by protease and phosphatasetreatment. The protease digestion of phosvitin resulted in the peptide cleavage of large fragment (a highly phosphorylated coreregion, 50 to 210 peptide) and small fragments (N-terminal 1 to 49 and C-terminal 211 to 217 peptides). The large fragmentlacking the small fragments did not show the excellent emulsifying properties, suggesting that small fragments of protein moietyplay an important role in emulsifying , properties. On the other hand, the effect of phosphatase treatment showed that electrostaticrepulsive force of phosphate in phosvitin has a significant affect on its emulsifying properties and that the protein moiety withabundant phosphorylated residues is also considered to be essential for the high emulsifying properties.