Improvement of Functional Properties of Egg White Protein through Glycation and Phosphorylation by Dry-heating

Egg white protein (EWP) was glycated with maltopentaose (MP) through the Maillard reaction and subsequently phosphorylated by 85°C dry-heating at pH 4.0 for 1 d in the presence of pyrophosphate.The functional properties of glycated, phosphorylated EWP were compared with those of native EWP and with EWP which was phosphorylated by dry-heating in the presence of pyrophosphate under the same conditions.The phosphorus content of EWP was increased to ~0.60% by phosphorylation, and to ~0.74% by glycation with MP and subsequent phosphorylation.The electrophoretic mobility of EWP increased through phosphorylation.The stability of EWP against heat-induced insolubility at pH 7.0 was considerably improved by phosphorylation alone and further by phosphorylation after glycation.The anti-ovalbumin antibody response was reduced significantly by glycation and phosphorylation, and further reduced by phosphorylation after glycation.The anti-ovomucoid antibody response was reduced significantly by glycation, phosphorylation and phosphorylation after glycation.The calcium phosphate-solubilizing ability of EWP was enhanced by both phosphorylation methods.