Why is use of aspartame limited to cold foods and soft drinks?

Explanation

### Step-by-Step Solution:

1. **Understanding Aspartame**: Aspartame is an artificial sweetener that is significantly sweeter than cane sugar, approximately 100 times sweeter. It is commonly used in various food products, especially in cold foods and soft drinks.

2. **Chemical Structure**: Aspartame is a methyl ester of a dipeptide formed from two amino acids: aspartic acid and phenylalanine. The structure consists of a chain where aspartic acid is linked to phenylalanine.

3. **Stability at Temperature**: The key reason for the limited use of aspartame in hot foods is its chemical stability. Aspartame is unstable at high temperatures, which means that when exposed to cooking temperatures, it can break down and lose its sweetness.

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