Improvement of foaming property of egg white protein by phosphorylation through dry-heating in the presence of pyrophosphate.
Egg white protein (EWP) was phosphorylated by dry-heating in the presence of pyrophosphate at pH 4 and 85 degrees C for 1 d, and the foaming properties of phosphorylated EWP (PP-EWP) were investigated. The phosphorus content of EWP increased to 0.71% as a result of phosphorylation. To estimate the foaming properties of EWP, the foams were prepared by 2 methods: bubbling of the 0.1% (w/v) protein solution and whipping of the 10% (w/w) protein solution with an electric mixer. The foaming power, which was defined as an initial conductivity of foam from 0.1% (w/v) protein solution, was a little higher in PP-EWP than in native EWP (N-EWP), and the foaming stability of PP-EWP was much higher than that of dry-heated EWP (DH-EWP) and N-EWP. The microscopic observation of foams from the 10% (w/w) solution showed that the foams of PP-EWP were finer and more uniform than those of N- and DH-EWP. Although there were no significant differences in the specific gravity and overrun of the foams between PP- and DH-EWP (P < 0.05), the specific gravity and overrun of the foams from PP-EWP were smaller and higher, respectively, than that of the foams from N-EWP. The drainage volume was smaller in the foams from PP-EWP than in those from N- and DH-EWP. These results demonstrated that phosphorylation of EWP by dry-heating in the presence of pyrophosphate improved the foaming properties, and that it was more effective for the foam stability than for the foam formation.
Hayashi
Y
Y
United Graduate School of Agricultural Sciences, Kagoshima Univ., Japan.
Nagano
S
S
Enomoto
H
H
Li
C-P
CP
Sugimoto
Y
Y
Ibrahim
H R
HR
Hatta
H
H
Takeda
C
C
Aoki
T
T
D011756:Diphosphates / Q000737:chemistry*; D004527:Egg Proteins / Q000737:chemistry*; D005524:Food Technology; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D010766:Phosphorylation; D012212:Rheology; D012995:Solubility; D013997:Time Factors
D011756:Diphosphates; D004527:Egg Proteins