The preservative which is ultimately excreted in urine as hippuric acid is .

Options

A. Sodium benzoate
B. Sodium metabisulphite
C. Sodium propionate
D. Sodium sorbate

Answer

**Step-by-Step Solution:**

1. **Identify the Preservative**: The question asks for a preservative that is ultimately excreted in urine as hippuric acid. The common food preservative that fits this description is sodium benzoate.

2. **Chemical Structure of Sodium Benzoate**: Sodium benzoate has the chemical formula C6H5COONa. It is derived from benzoic acid (C6H5COOH) by neutralizing it with sodium hydroxide.

3. **Metabolism of Sodium Benzoate**: Once ingested, sodium benzoate is metabolized in the liver. During this process, it combines with glycine (an amino acid) to form hippuric acid.

4. **Chemical Structure of Hippuric Acid**: The chemical formula for hippuric acid is C6H5C(O)NHCH2COOH. It is the conjugate of benzoic acid and glycine.

5. **Excretion of Hippuric Acid**: After its formation, hippuric acid is excreted from the body through urine. This process is a way for the body to eliminate excess substances.

6. **Conclusion**: Therefore, the preservative that is ultimately excreted in urine as hippuric acid is sodium benzoate.

**Final Answer**: Sodium benzoate.

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