Table 3. Effects of different drying methods on AA composition of TCH

AA	Sample (g/100 g protein)
AA	FD	OD	VD
Aspartic acid^NS	5.33 ± 0.02	5.36 ± 0.02	5.42 ± 0.07
Glutamic acid	10.25 ± 0.09^C	10.57 ± 0.04^B	10.80 ± 0.10^A
Serine	3.23 ± 0.03^B	3.17 ± 0.02^C	3.45 ± 0.03^A
Histidine^*	7.07 ± 0.06^B	7.64 ± 0.04^A	6.41 ± 0.06^C
Glycine	14.69 ± 0.30^B	15.52 ± 0.10^A	15.61 ± 0.17^A
Threonine^*	3.13 ± 0.05^B	3.13 ± 0.05^B	3.24 ± 0.04^A
Arginine^NS	7.75 ± 0.03	7.75 ± 0.04	7.85 ± 0.07
Alanine	7.32 ± 0.08^B	7.65 ± 0.05^A	7.76 ± 0.08^A
Tyrosine^NS	1.23 ± 0.23	1.00 ± 0.01	1.15 ± 0.03
Cysteine	20.67 ± 0.10^A	19.40 ± 0.09^B	19.95 ± 0.62^A
Valine^*	3.04 ± 0.05^A	2.87 ± 0.19^AB	2.59 ± 0.27^B
Methionine^*	1.88 ± 0.15^A	1.63 ± 0.02^B	1.76 ± 0.03^AB
Phenylalanine^NS	2.15 ± 0.23	1.99 ± 0.02	2.01 ± 0.05
Isoleucine^*	1.69 ± 0.19^A	1.63 ± 0.01^A	1.40 ± 0.05^B
Leucine^*NS	3.29 ± 0.13	3.30 ± 0.03	3.34 ± 0.07
Lysine^*NS	4.14 ± 0.19	4.37 ± 0.03	4.25 ± 0.05
Proline^NS	3.13 ± 0.32	3.02 ± 0.02	3.02 ± 0.07
EAA	24.24 ± 0.06^A	24.57 ± 0.06^A	22.99 ± 0.09^B
HAA^NS	55.72 ± 0.34	55.02 ± 0.06	55.43 ± 0.20
AAA	3.38 ± 0.00^A	2.99 ± 0.01^B	3.17 ± 0.01^A
NCAA	15.58 ± 0.05^B	15.93 ± 0.02^AB	16.22 ± 0.02^A
PCAA	18.96 ± 0.09^B	19.75 ± 0.00^A	18.51 ± 0.01^B

Different uppercase letters indicate significant differences among the mean value of each treatment (p < 0.05).
Essential AAs.
AA, amino acid; TCH, tuna cooking juice concentrate hydrolysate; FD, freeze dried TCH; OD, hot air dried TCH; VD, vacuum-dried TCH; NS, not significant; EAA, essential AAs; HAA, hydrophobic AAs; AAA, aromatic AAs; NCAA, negatively charged AAs (acidic AAs); PCAA, positively charged AAs (basic AAs).