It was observed that the viscosity of “Kimizu” decreased when egg yolk was mixed with the starch paste. Experiments were carried out to find out its reasons, and the following results were obtained.
1) The viscosity of the starch paste decreased remarkably when egg yolk was mixed with the starch paste of 70°C.
2) By mixing egg yolk, the starch paste which had contained sugar or salt decreased its viscosity, on the other hand that which had contained vinegar increased the viscosity.
3) In cases where oleic acid or lecithin was added to the starch paste, there was no change in the viscocity of the paste. When α-amylase was added, the viscosity decreased.
4) Amount of reducing sugar in starch mixed with egg yolk solusion was maximum at 50°C, pH 6.9.
5) The thin layer chromatogram detected maltose in the starch mixed with egg yolk or α-amylase.
As a result of these studies, it is supposed that the changes in the viscosity of the starch paste mixed with egg yolk are caused by α-amylase in the egg yolk.
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