Table 2. Amino acid composition of the protein hydrolysate from the catfish by-product

Amino acids	Content (mg/g protein)
Arginine	30.24
Serine	5.04
Aspartic	42.85
Glutamic	38.40
Hydroxylproline	26.54
Glycine	40.92
Threonine	12.45
Alanine	39.88
Aminobutyric acid	2.82
Proline	18.83
Methionine	14.38
Valine	12.45
Phenylalanine	3.56
Cysteine/cystine	10.97
Isoleucine	3.56
Tyrosine	36.17
Leucine	7.41
Ornithine	46.11
Lysine	15.57
Histidine	12.01
Total non-essential amino acids	81.39
Total essential amino acids	338.77
Total amino acids	420.16