PDCAAS
PDCAAS stands for Protein Digestibility-Corrected Amino Acid Score. It is the FDA's official method for ranking the quality of a protein, scoring from 0 to 1. Whey, casein, egg and soy all score the maximum 1.0; rice and pea score 0.7 to 0.8; collagen and gelatin score very low.
Why It Matters
PDCAAS is what shows up on most protein labels when 'protein quality' is mentioned. It rewards complete proteins that are easy to digest and penalizes incomplete proteins (like collagen and grain-only formulas). PDCAAS has limitations (it caps at 1.0 and overrates some proteins) but it is still a useful first filter.
How to Spot It on a Label
PDCAAS is rarely on the front of a label. The clue is usually in the marketing: 'highest-quality protein' or 'complete protein score' usually means PDCAAS 1.0. Blended plant proteins (pea plus rice) can reach 1.0 because the amino gaps cancel out.
Examples from real products
Related Terms
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