What is an amino acid score?

It is important to take in good quality protein in a combination of foods that provide the necessary amino acids, in order to acquire the required proteins.

There is a method of determining nutritional value from the constituent ratio of specific foods containing essential amino acids. The numerical values calculated through this method are known as the “Amino Acid Score”. This indicates the level of each amino acid as a ratio (%) in relation to a reference value. Proteins that have an amino acid score of 100 for each essential amino acid are considered good quality proteins.

Those that do not reach 100 are known as “Limiting amino acids”. These are named in sequence from the lowest value and called “First-limiting amino acid”, “Second-limiting amino acid”, etc.

The amino acid score for soybeans is 100. Likewise, tofu, which is made from soybeans, also has an amino acid score of 100. {FAO/WHO/UNU (1985)}

Generally deficient amino acids

Amino acid scores for other foods