Table 3. Amino acid contents of skipjack tuna viscera, tuna viscera protein hydrolysate and yeast extract (g/100 g sample)

Amino acid	Skipjack tuna viscera	Tuna viscera protein hydrolysate	Yeast extract
Aspartic acid	1.91 ± 0.04	0.0028 ± 0.0007	3.12 ± 0.07
Glutamic acid	2.80 ± 0.10	0.0067 ± 0.0016	6.95 ± 0.15
Serine	0.88 ± 0.05	0.0015 ± 0.0002	1.41 ± 0.02
Histidine1)	1.33 ± 0.18	0.0290 ± 0.0012	0.42 ± 0.03
Glycine	0.91 ± 0.04	0.0007 ± 0.0000	1.81 ± 0.12
Threonine1)	1.87 ± 0.06	0.0100 ± 0.0008	1.05 ± 0.05
Arginine	1.07 ± 0.19	0.0051 ± 0.0010	1.97 ± 0.04
Alanine	0.98 ± 0.07	0.0013 ± 0.0002	1.63 ± 0.08
Tyrosine	0.82 ± 0.19	0.0008 ± 0.0002	0.98 ± 0.02
Cysteine	1.01 ± 0.16	0.0085 ± 0.0011	2.35 ± 0.06
Valine1)	1.05 ± 0.05	0.0029 ± 0.0005	1.73 ± 0.04
Methionine1)	0.56 ± 0.14	0.0019 ± 0.0005	0.76 ± 0.03
Phenylalanine1)	0.86 ± 0.14	0.0016 ± 0.0003	1.43 ± 0.04
Isoleucine1)	0.89 ± 0.10	0.0023 ± 0.0003	1.56 ± 0.02
Leucine1)	1.28 ± 0.08	0.0039 ± 0.0004	2.76 ± 0.05
Lysine1)	ND	ND	0.72 ± 0.01

Values are presented as mean ± SD (n = 3).
Essential amino acid.
ND, not detect.