Question

Identify the factors that decrease the stability of egg foams;
(A). Acidity
(B). Fat content
(C). Salt content
(D). Sugar
Choose the most appropriate answer from the options given below:

• A. (B) and (C) only
• B. (A), (B) and (D) only
• C. (A), (B), (C) and (D)
• D. (B), (C) and (D) only

Hint:

To remember egg foam chemistry:
\textbf{Stabilizers (Friends):} Acid (cream of tartar), Sugar. They make the foam stronger.
\textbf{Destabilizers (Foes):} Fat (yolk), Salt. They make the foam weaker.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
Egg foam stability refers to the ability of the whipped foam (meringue) to hold its structure and not collapse or leak liquid (weep) over time. Various ingredients can either help or hinder this stability. The question asks which factors decrease stability.
Step 3: Detailed Explanation:
Let's analyze the effect of each factor:
- (A) Acidity: The addition of an acid (like cream of tartar or lemon juice) increases foam stability. The acid helps to denature the egg white proteins and allows them to form a stronger, more stable network around the air bubbles.
- (B) Fat content: Fat is highly detrimental to both the formation and stability of egg foams. Even a tiny trace of fat (e.g., from a speck of egg yolk) will interfere with the ability of the proteins to form a cohesive film around the air bubbles, causing the foam to be weak and collapse easily. Therefore, fat decreases stability.
- (C) Salt content: Adding salt to egg whites decreases foam stability. Although salt can decrease the time it takes to form a foam, it weakens the protein structure, making the foam less stable and more likely to weep over time.
- (D) Sugar: Sugar has a major stabilizing effect on egg foams. It should be added after the foam has reached a soft peak stage. The sugar dissolves in the liquid phase of the foam, increasing its viscosity and protecting the protein structure from over-coagulation. This results in a very strong, stable, and glossy meringue. Therefore, sugar increases stability.
The factors that decrease stability are fat and salt.
Step 4: Final Answer:
Fat content and salt content both decrease the stability of egg foams. Therefore, option (A) which includes (B) and (C) only, is the correct answer.