Table 1.

Changes in free amino acid content in soaked, boiled, and fermented soybeans by simulated digestion.

Amino acids	‘S’, Soaked bean		‘B’, Boiled bean		‘F’, Fermented bean
	Stage 0	Stage 4	Stage 0	Stage 4	Stage 0	Stage 4
Thr	0.58 ± 0.05	0.73 ± 0.05	0.00 ± 0.00	2.49 ± 0.04	1.93 ± 0.02	4.65 ± 0.06
Ser	0.87 ± 0.05	1.10 ± 0.05	0.00 ± 0.00	2.94 ± 0.04	3.13 ± 0.03	6.65 ± 0.06
Asp	1.12 ± 0.09	0.89 ± 0.00	0.00 ± 0.00	3.90 ± 0.01	3.45 ± 0.03	8.01 ± 0.73
Glu	4.37 ± 0.07	3.16 ± 0.01	0.00 ± 0.00	4.33 ± 0.03	26.66 ± 0.26	44.38 ± 0.24
Gly	0.58 ± 0.08	1.18 ± 0.07	0.00 ± 0.00	2.41 ± 0.06	5.17 ± 0.46	8.83 ± 0.95
Ala	3.35 ± 0.03	2.29 ± 0.13	11.91 ± 0.95	11.00 ± 0.85	6.77 ± 0.68	12.35 ± 0.34
Val	5.58 ± 0.02	5.69 ± 0.09	5.09 ± 0.36	9.65 ± 0.55	14.57 ± 0.67	26.70 ± 0.27
Met	0.62 ± 0.02	1.05 ± 0.02	0.00 ± 0.00	2.79 ± 0.06	6.46 ± 0.74	15.05 ± 0.61
Cysta*	1.96 ± 0.03	3.01 ± 0.06	1.98 ± 0.14	3.36 ± 0.09	4.78 ± 0.08	8.92 ± 0.54
Ile	0.57 ± 0.01	1.74 ± 0.02	0.00 ± 0.00	3.91 ± 0.07	9.18 ± 0.90	20.93 ± 0.31
Leu	0.63 ± 0.06	14.22 ± 0.26	0.00 ± 0.00	28.21 ± 0.45	24.98 ± 0.79	91.09 ± 0.82
Tyr	1.03 ± 0.07	8.01 ± 0.09	1.51 ± 0.14	25.68 ± 0.43	22.22 ± 0.23	86.40 ± 0.67
Phe	0.99 ± 0.05	15.58 ± 0.01	2.49 ± 0.20	41.73 ± 0.27	37.45 ± 0.53	123.78 ± 0.36
His	1.75 ± 0.12	1.65 ± 0.01	1.91 ± 0.03	4.07 ± 0.80	11.87 ± 0.36	18.87 ± 0.99
Lys	1.84 ± 0.13	3.81 ± 0.03	1.93 ± 0.05	18.48 ± 0.40	34.04 ± 0.35	133.58 ± 0.57
Trp*	n/a	n/a	n/a	n/a	n/a	n/a
Arg	10.80 ± 0.01	14.61 ± 0.08	14.90 ± 1.10	83.16 ± 0.14	3.23 ± 0.20	160.19 ± 0.99
Pro	0.00 ± 0.00	0.00 ± 0.00	0.00 ± 0.00	0.00 ± 0.00	2.56 ± 0.00	2.46 ± 0.00
Total	36.62 ± 0.89	78.73 ± 1.96	41.72 ± 2.97	248.11 ± 4.29	218.45 ± 6.33	772.86 ± 8.47

Each value represents the mean of three replications ± standard deviation.

*Cysteine (Cys) was determined in the form of cystathionine (Cysta). Tryptophan (Trp) cannot be reported because it is unstable and produces ammonia, so it was not obtained in the amino acid standard solution.