is collagen a complete protein
Protein Quality. Collagen is not a complete protein because it is lacking in the amino acid tryptophan. A Protein Digestibility Corrected Amino Acid Score (PDCAA) of a complete protein is 1.0.ollagen is a protein found in the muscle and connective tissue of animals. Hydrolyzed collagen protein supplements are typically made from the bones and skin of cows, horses or pigs.