Table 1.

Outcomes from the iterative PDCAAS calculations devised to identify the highest percentage of each type of collagen peptides that may be incorporated in the standard American diet, while maintaining dietary protein quality.

Commonly Consumed Dietary Sources of Collagen Peptides	PDCAAS Equals 1.0 (“High” Dietary Protein Quality)		PDCAAS Equals 0.75 (“Good” Dietary Protein Quality)
	Collagen (%)	First Limiting Amino Acid	Collagen (%)	First Limiting Amino Acid
Porcine, sample A [27]	39%	Tryptophan	54%	Tryptophan
Porcine, sample B [27]	39%	Tryptophan	54%	Tryptophan
Porcine, sample C [27]	39%	Tryptophan	54%	Tryptophan
Porcine, sample D [27]	36%	Cysteine + methionine	54%	Tryptophan
Bovine (GELITA AG)	39%	Cysteine + methionine	54%	Tryptophan
Marine [28]	39%	Tryptophan	54%	Tryptophan