Table 2. Change of free amino acid contents during the solid-state fermentation of soybeans by mycelia of Tricholoma matsutake

Contents1) (mg/g) Fermentation time (day)
0 3 6 9 12
Non-essential amino acids (NEAAs)
Phosphoetanolamine 0.12±0.00 ND2) ND ND ND
Urea 0.39±0.00b 0.69±0.01a ND ND ND
Proline ND ND 0.65±0.01b 0.51±0.01c 1.61±0.02a
Aspartic acid 0.43±0.00e 0.59±0.01d 1.14±0.01c 2.05±0.02b 4.31±0.04a
Serine 0.12±0.00e 0.18±0.00d 0.27±0.00c 1.39±0.01b 3.51±0.04a
Glutamic acid 3.13±0.03b 1.97±0.02d 2.06±0.02c 3.15±0.03b 8.37±0.08a
Sarcosine ND ND 0.15±0.00b ND 0.19±0.00a
Aminoadipic acid 0.09±0.00d 0.09±0.00d 0.44±0.00b 0.26±0.00c 0.63±0.01a
Glycine 0.22±0.00d 0.16±0.00e 0.33±0.00c 0.53±0.01b 1.44±0.01a
Alanine 0.38±0.00de 0.29±0.00e 0.79±0.01c 1.67±0.02b 2.94±0.03a
Citrulline 0.22±0.00b 0.19±0.00c 0.22±0.00b 0.23±0.00ab 0.24±0.00a
α-Aminobutyric acid 0.03±0.00d 0.02±0.00d 0.44±0.00a 0.24±0.00b 0.22±0.00c
Cystine 0.25±0.00d 0.22±0.00e 0.31±0.00c 0.55±0.01b 0.75±0.00a
Cystathionine ND ND 0.29±0.00b 0.26±0.00c 0.46±0.01a
Tyrosine 0.14±0.00e 0.18±0.00d 1.13±0.01c 2.37±0.02b 4.31±0.00a
β-Alanine 0.13±0.00e 0.41±0.00d 1.31±0.01b 1.19±0.01a 0.51±0.04c
β-Aminoisobutyric acid 0.01±0.00e 0.57±0.01d 1.98±0.02c 2.61±0.03b 3.08±0.01a
γ-Aminobutyric acid 0.37±0.00a 0.19±0.00c 0.14±0.00d 0.18±0.00c 0.33±0.03b
Aminoethanol ND ND 0.12±0.00b 0.16±0.00a 0.17±0.00a
Hydroxylysine 0.01±0.00d 0.02±0.00d 0.93±0.01a 0.83±0.01c 0.86±0.00b
Ornithine ND 0.04±0.00d 0.38±0.00c 0.43±0.00b 0.48±0.01a
3-Methylhistidine ND ND ND 0.06±0.00b 0.18±0.00a
Anserine ND ND 0.94±0.01a 0.79±0.01b 0.62±0.01c
Carnosine ND ND 0.05±0.00c 0.29±0.00a 0.12±0.00b
Arginine 2.44±0.02d 1.75±0.02e 3.02±0.03c 4.78±0.05b 8.39±0.08a
Total 8.48 7.56 17.09 24.53 43.72
Essential amino acids (EAAs)
Threonine 0.09±0.00d 0.09±0.00d 0.34±0.00c 0.84±0.01b 2.30±0.02a
Valine 0.16±0.00d 0.17±0.00d 1.72±0.02c 1.81±0.02b 2.97±0.03a
Methionine 0.09±0.00d 0.09±0.00d 0.79±0.01c 1.08±0.01b 1.54±0.02a
Isoleucine 0.07±0.00d 0.08±0.00d 0.75±0.01c 1.38±0.01b 2.68±0.03a
Leucine 0.11±0.00e 0.26±0.00d 1.62±0.02c 4.49±0.04b 6.87±0.07a
Phenylalanine 0.28±0.01e 0.55±0.01d 2.79±0.03c 5.55±0.06b 7.55±0.08a
Lysine 0.13±0.00e 1.01±0.01d 3.28±0.03c 7.93±0.08b 11.07±0.11a
Histidine 0.09±0.00e 0.12±0.00d 0.77±0.01c 1.19±0.01b 1.79±0.02a
Total 1.02 2.37 12.06 24.27 36.77
Sum of amino acids 9.5 9.93 29.15 48.8 80.49
Ammonia 0.29±0.01e 0.37±0.01d 1.31±0.03c 1.65±0.03b 3.12±0.06a
All values are mean±SD (n=3). a-dMeans with different letters differ significantly (p<0.05).
ND, not detected.