PDCAAS (Protein Digestibility Corrected Amino Acid Score)

An earlier protein quality evaluation method, now recommended to be replaced by DIAAS per FAO/WHO. PDCAAS measures amino acid content corrected for digestibility relative to a reference amino acid pattern but caps its score at 1.0 — which can overstate the quality of plant proteins with limiting amino acids by not capturing deficiencies relative to a complete protein. DIAAS is more precise for distinguishing protein quality between animal and plant sources.