Preparing Preferable Soft-boiled Eggs: Effects of Temperature and Holding Time on the Coagulation of Soft-boiled Egg

Abstract

This study was conducted for analysing the effects of temperature and holding time (at the same temperature) on the coagulation of eggs while preparing soft-boiled eggs having preferable tastes.

The obtained results are outlined below:

— Upon setting whole eggs in thermostat water at 65°C, 68°C, and 70°C, the corresponding time periods required for the temperature of eggs' centres to reach the water temperature are found to be 27 min, 28 min, and 30 min, respectively. Furthermore, the egg whites retain their fluidity at other temperatures, whereas the heights of egg yolks vary according to the associated water temperature.

— At 65°C, the egg white is found to be in liquid state, and its fluidity is retained even after 210 min, though decreased as the holding time. However, the egg white at 68°C has reduced fluidity owing to the longer holding time. At 70°C and after 30 min, fluidity of the egg white is not observed.

— The heights of egg yolks at 65°C and 68°C tend to increase upon increasing the holding time. However, no significant difference is observed at 70°C.

Hence, it can be concluded that the coagulation states of the egg white and egg yolk are affected by the associated temperature and holding time, respectively. Based on these results, indicators can be developed for preparing preferable soft-boiled eggs.