Table 3 Free amino acid content (ppm) of Doenjang fermented with Aspergillus oryzae SCF-6 and protease

Amino acids Control Protease A1) Protease B Protease A+B
0 week 8 week 0 week 8 week 0 week 8 week 0 week 8 week
Histidine 10.70±0.04 22.53±1.23 9.48±0.32 21.81±0.70 17.16±0.18 26.15±0.91 14.80±0.03 26.85±2.41
Serine 17.53±0.49 41.72±1.70 18.53±0.63 40.26±0.48 22.79±0.16 44.30±0.35 22.64±0.39 44.64±5.46
Arginine 17.72±1.03 18.81±0.78 21.44±0.84 22.28±0.15 55.73±2.78 30.80±0.33 47.82±0.10 28.75±3.09
Glycine 13.03±0.13 33.71±0.85 12.77±0.75 32.18±0.71 16.48±0.81 38.55±0.72 15.54±0.40 37.49±3.49
Aspartic acid 12.09±0.90 38.91±3.08 9.03±0.09 25.37±3.04 9.74±0.89 29.92±1.21 9.78±0.80 27.82±4.71
Glutamic acid 84.12±5.74 137.32±8.42 69.69±0.08 96.76±9.36 71.53±4.75 100.58±3.15 79.57±4.32 98.33±12.67
Threonine 14.67±0.13 30.77±1.14 14.61±0.16 15.76±12.68 19.82±0.11 35.17±0.43 18.72±0.25 36.58±4.93
Alanine 27.19±1.61 40.87±1.35 23.66±0.19 33.23±2.30 23.50±1.25 35.11±0.18 25.53±0.71 33.72±3.68
Proline 16.13±0.41 35.84±0.67 14.91±0.74 31.94±0.59 26.05±0.51 47.83±0.40 22.56±0.04 42.42±2.94
Cysteine 4.07±0.53 0.17±0.02 4.73±0.18 0.20±0.07 4.44±0.12 0.27±0.01 5.16±0.23 0.33±0.07
Lysine 42.60±2.53 53.77±2.56 34.98±2.21 33.76±5.63 40.85±4.09 33.61±0.38 45.03±2.25 30.10±4.13
Tryptophan 32.67±0.78 44.04±0.28 31.92±1.25 48.88±3.07 45.02±1.50 40.95±1.28 42.81±1.23 46.42±5.08
Methionine 11.19±0.24 10.01±0.51 11.88±0.02 11.08±0.47 13.94±0.26 11.10±0.55 15.11±0.05 12.32±1.37
Valine 23.79±1.52 0.88±0.02 18.99±0.03 0.82±0.02 29.06±1.61 0.95±0.01 28.17±0.38 0.91±0.08
Isoleucine 19.87±0.99 49.81±1.02 17.34±0.05 46.67±1.14 28.35±1.72 56.05±0.79 26.61±0.20 54.47±4.56
Lucine 50.88±2.47 86.62±1.98 54.73±0.14 88.13±2.09 69.01±4.38 92.01±1.56 72.35±0.26 93.77±8.03
Phenylalanine 47.51±1.16 75.48±0.62 51.68±1.95 85.66±5.35 68.33±0.47 92.39±3.36 65.18±2.23 100.62±9.79
Protease A isolated from Bacillus licheniformis, Protease B isolated from Aspergillus species, Protease A+B=0.5:0.5 ratio.