The Effect of Copper Ion on the Quality of Whipped Egg White

Abstract

The whipped egg white with sugar (Meringue), prepared in copper bowl has been said to have good quality. The mechanism of the effect of copper bowl was examined in this study to the whipped egg white without sugar. Although the whipped egg white prepared in the copper bowl showed the almost the same density with those prepared in the glass bowl and stainless steel bowl, it is superior in the stability of the whipped egg white to the others. The whipped egg white prepared in the copper bowl contained about 27 times more copper compared with those in the egg white. Therefore, in order to examine the role of copper, the characterization of the whipped egg white added 1 mg% of copper powder, glass powder as control or CuCl₂ was performed. The whipped egg white by addition CuCl₂ showed the similar properties with those prepared in the copper bowl, which means that the copper ion (Cu²⁺) played an important role to stabilize the whipped egg white. Copper ion might prevent the egg white protein from S-S bond formation during whipping. Then, the characterization of whipped egg white prepared with 1 mg% of 2-mercaptoethanol was performed in order to examine the role of S-S bond. 2-Mercaptoethanol increased the stability of the whipped egg white. In addition, the form in the whipped egg white prepared in the copper bowl and those with 2-mercaptoethanol were relatively uniform in size and shape by microscope observation (×200) comparing with those in glass bowl and stainless steel bowl, which might be concerned with the stability of the whipped egg white.