How Does Citric Acid Affect The Denaturation Of Ovalbumin

Introduction:
I decided to try to cook meringue. While researching how to cook meringue, I learned that meringue is created from the denaturation of ovalbumin, the main protein in egg whites. Denaturation is when a protein’s structure is disrupted. Ovalbumin is denatured by heat. In my science class, I had learned that heat and pH affect the denaturation of protein. I became curious about how changing the pH would affect the denaturation of ovalbumin when cooking meringue. So I decided to add lemon juice to egg whites and heat the egg whites. The citric acid in the lemon juice would lower the pH of the egg whites. I tried to find the answer to the question, “How does citric acid affect the denaturation of the protein ovalbumin in egg whites by heat?”
In amino acids, hydrogen atoms and oxygen atoms are held together by hydrogen bonds. These hydrogen bonds give proteins their shape. Denatured occurs if some of the protein’s hydrogen bonds are broken and the protein’s shape changes. Hydrogen bonds break when exposed to heat and acids.

Hypothesis:
Citric acid will cause ovalbumin to denature faster than it would have without it.

Variables:
The independent value is the presence of lemon juice. The dependent value is the amount of time taken for ovalbumin to denature.

Safety Issues:
The eggs may harm someone who is allergic to eggs. I will keep the eggs away from everyone in the room to prevent someone from being too close to them and having an allergic reaction. Also, raw eggs may have bacteria on them. I will wear gloves to protect myself from bacteria.

Materials:
200 mL water
1 250 mL beaker
1 ring stand
1 bunsen burner
2 test tubes
6 eggs
1 cup lemon juice