Table 5. Changes in free amino acid content in black barley makgeolli according to fermentation periods

Free amino acids (μg/mL)	Fermentation period (day)
Free amino acids (μg/mL)	0	3	6	9	12
P-Ser¹⁾	ND²⁾	29.37±0.06^3)d4)	29.59±0.09^c	32.68±0.13^b	34.62±0.12^a
1MeHis	ND	1.98±0.10^d	2.30±0.05^c	2.73±0.13^b	2.88±0.02^a
3MeHis	2.63±0.25^bc	ND	9.59±0.07^a	7.46±6.46^ab	11.35±1.14^a
α-ABA	27.77±0.39^e	69.46±0.32^d	84.63±0.26^c	84.63±0.26^b	106.70±0.50^a
Ans	9.86±0.41^e	39.04±0.23^d	49.39±0.73^c	62.42±0.61^b	70.08±0.16^a
Arg	54.87±0.21^a	ND	ND	ND	ND
β-AiBA	14.66±0.09^e	54.18±0.18^d	61.11±0.24^c	69.94±0.26^b	74.10±0.27^a
β-Ala	11.39±0.16^a	ND	ND	ND	ND
Car	4.37±0.00^e	25.56±0.17^d	28.29±0.16^c	33.56±0.41^b	35.72±0.33^a
Cit	83.16±0.49^e	314.20±0.79^d	348.67±0.15^c	412.05±1.02^b	438.76±1.47^a
Cys	50.14±0.34^e	138.29±0.27^d	171.77±0.07^c	216.62±0.90^b	244.54±1.00^a
Cysthi	5.49±0.11^e	14.31±0.08^d	16.97±0.10^c	20.73±0.04^b	22.48±0.13^a
EOHNH₂	6.41±0.12^e	14.63±0.06^d	16.42±0.08^c	18.46±0.10^b	19.57±0.06^a
γ-ABA	31.22±0.24^c	64.30±0.17^b	50.72±30.10^bc	110.42±0.45^a	128.30±0.38^a
Glu	60.07±0.48^e	209.44±0.55^d	233.56±0.30^c	262.23±0.79^b	264.63±0.90^a
His	20.08±0.41^e	57.83±0.41^d	67.49±0.02^c	82.64±0.26^b	91.60±0.29^a
Hylys	ND	6.56±0.08^c	7.21±0.04^b	7.96±0.18^a	8.06±0.04^a
Ile	27.61±0.30^e	66.74±0.16^d	85.67±0.01^c	109.44±0.28^b	125.66±0.49^a
Leu	56.77±0.37^e	180.88±0.41^d	230.84±0.47^c	298.36±0.98^b	338.90±1.20^a
Lys	32.57±0.36^e	152.13±0.26^d	190.17±0.12^c	236.93±0.79^b	262.15±0.94^a
Met	15.73±0.12^e	66.48±0.16^d	83.01±0.18^c	104.74±0.40^b	117.28±0.49^a
NH₃	10.44±0.11^e	20.41±0.14^d	22.81±0.27^c	29.00±0.03^b	32.91±0.22^a
Orn	4.89±0.14^e	23.90±18.23^a	3.23±0.05^b	3.74±0.03^b	4.03±0.06^b
PEA	ND	6.52±0.04^c	6.58±0.00^c	7.41±0.26^b	7.81±0.14^a
Phe	41.69±0.40^e	117.32±0.23^d	147.13±0.38^c	190.66±0.66^b	220.32±0.73^a
Pro	105.01±1.44^e	354.81±0.81^d	383.92±0.44^c	439.21±1.91^b	471.46±1.47^a
Sar	14.62±6.55^d	57.68±0.55^c	69.51±0.41^b	79.27±0.14^a	84.15±0.85^a
Ser	22.42±0.06^e	66.45±0.15^d	76.47±0.04^c	97.15±0.35^b	108.35±0.43^a
Thr	13.07±0.09^e	47.61±0.06^d	55.97±0.07^c	68.09±0.15^b	75.16±0.24^a
Tyr	44.38±0.45^e	102.36±0.08^d	127.28±0.19^c	159.00±0.77^b	180.90±0.55^a
Urea	ND	64.54±0.84^c	65.90±0.55^c	75.05±1.62^b	79.68±0.69^a
Val	3.27±0.04^e	27.61±0.04^d	30.51±0.01^c	35.96±0.09^b	38.21±0.06^a
Total	774.57	2,394.58	2,756.71	3,372.89	3,700.36

P-Ser, D,L-O-Phosphoserine; 1MeHis, L-1-Methylhistidine; 3MeHis, L-3-Methylhistidine; α-ABA, L-α-Amino-n-Butyric Acid; Ans, L-Anserine; Arg, L-Arginine; β-AiBA, β-Aminoisobutyric acid; β-Ala, β-Alanine; Car, L-Carnosine; Cit, L-Citrulline; Cys, L-Cystine; Cysthi, L-Cystathionine; EOHNH₂, Ethanolamine; γ-ABA, γ-AminoButyric acid; Glu, L-Glutamic acid; His, L-Histidine; Hylys, D,L&allo-Hydroxylysine; Ile, Isoleucine; Leu, L-Leucine; Lys, L-Lysine; Met, L-Methionine; NH₃, Ammonia; Orn, L-Ornithine; PEA, O-Phosphoethanolamine; Phe, Phenylalanine; Pro, L-Proline; Sar, Sarcosine; Ser, L-Serine; Thr, L-Threonine; Tyr, L-Tyrosine; Val, L-Valine.
ND, not detected.
All values are mean±SD (n=3).
Means with different superscript letters in the same row are significantly different at p<0.05 by Duncan’s multiple range test (a>b>c>d>e).