Question

1.) The increased opacity that occurs when egg white is heated is caused by

A) sonic vibrations

B) rapid change in pH

C) the increasing solubility of the protein

D) decreasing solubility of the protein

E) none of the above

2. As eggs deteriorate, the pH of the egg white

A) is lowered

B) is raised

C) disappears

D) denatures

E) none of the above

3. If a starch-thickened pudding thins instead of thickening some after egg yolk has been added, the problem is caused by

A) inadequate heating to inactivate the alpha-amylase in the starch

B) adding a little egg white, too

C) failing ti beat the yolk first

D) inadequate heating to inactivate the alpha-amylase in the yolk

E) too much sugar

Answer 1

1.D. decreasing solubility of the proteins.

When egg whites are heated ,the proteins in the egg get denatured and loss of solubility .Egg coagulates and changes colour from transparent to opaque.This is the reason for the increased opacity .

2.B.is raised

The pH of the egg white is alkaline (7.6) normally and as the egg deteriorates the pH is raised till 9.2.