Reference
Amino Acid Profile
**Amino acid profile** is the specific proportion and quantity of the individual amino acids that make up a protein — particularly the ratio of essential amino acids (EAAs), which the body cannot synthesize, to non-essential amino acids (NEAAs), which it can.
Essential versus non-essential amino acids
Proteins are built from twenty amino acids. Nine of these are classified as essential, meaning they must be obtained from diet because the human body cannot produce them. The remaining amino acids are non-essential or conditionally essential. A protein’s amino acid profile records how much of each is present, usually expressed per 100 grams of protein.
The branched-chain amino acids — leucine, isoleucine, and valine — sit within the essential group. Leucine is the primary amino acid trigger for muscle protein synthesis, which is why the leucine content of a profile draws particular attention.
What makes a protein complete
A protein is called complete when it supplies all nine essential amino acids in amounts adequate to meet human requirements. A protein lacking sufficient quantity of one or more EAAs is incomplete, and the EAA in shortest supply relative to the reference pattern is its limiting amino acid. Many plant proteins are limited in lysine or in the sulfur amino acids methionine and cysteine.
How amino acid profiles are scored
Two methods translate a profile into a quality score. The PDCAAS (Protein Digestibility-Corrected Amino Acid Score) compares a food’s amino acid profile against a reference requirement pattern and corrects for digestibility, with results truncated at a maximum of 1.00. The DIAAS (Digestible Indispensable Amino Acid Score), proposed by the FAO in 2013, uses ileal digestibility and does not truncate scores. Two proteins can share an identical PDCAAS yet differ in how they stimulate muscle protein synthesis, because the underlying profiles and absorption kinetics are not the same.
Potato protein’s profile
Potato protein isolate contains all nine essential amino acids. Roughly 37% of its amino acids are essential, compared with about 43% for whey protein isolate (Amino Acids, 2018, PMID:30167963). Its amino acid score has been reported at 65% (PMID:34507729), while its DIAAS has been reported as high as 100 (Food Science & Nutrition, Herreman et al., 2020, PMID:33133540) — placing it among the higher-quality plant proteins. For a broader overview of the ingredient, see what potato protein is.
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