In the chemical score, the most limiting essential amino acid is compared to its amount in which standard protein?

• A. Egg protein
• B. Milk protein
• C. Soy protein
• D. Wheat protein

Answer: (A)

The chemical score tests how well a protein meets human essential amino acid needs by comparing each essential amino acid’s amount in the protein to its amount in a reference pattern. The limiting amino acid is the one with the smallest ratio to that reference, so the overall score is driven by that shortage. The standard reference protein used for this comparison is egg protein, chosen because it provides a high-quality, well-balanced profile of essential amino acids and good digestibility. So the most limiting amino acid is identified by comparing its content in the test protein to its amount in egg protein.