Table 1.

Contents of free amino acids in spinach extracts (mg/100 g).

Amino Acids	Ethanol Extract	Water Extract	Frozen Powder
L-Phenylalanine	ND	44.13 ± 0.21	1.48 ± 0.15
L-Aspartic Acid	26.11 ± 1.31	ND	ND
L-Threonine	32.28 ± 1.54	68.44 ± 1.36	11.18 ± 0.45
L-Serine	32.11 ± 1.36	98.80 ± 6.32	23.78 ± 0.36
L-Asparagine	23.68 ± 0.25	3.43 ± 0.24	30.55 ± 0.33
L-Glutamate	23.65 ± 0.84	1171.38 ± 15.27	146.69 ± 2.58
L-Glutamine	29.13 ± 0.25	ND	62.88 ± 3.36
L-Proline	549.98 ± 5.64	564.45 ± 4.25	145.72 ± 4.68
Glycine	9.24 ± 0.24	66.79 ± 0.65	5.45 ± 0.65
L-Alanine	62.88 ± 2.65	233.74 ± 3.54	20.23 ± 0.36
L-Citrulline	13.98 ± 0.25	44.80 ± 3.54	2.54 ± 0.04
α-Aminobutyric acid	8.74 ± 0.21	17.03 ± 0.25	0.65 ± 0.15
L-Valine	80.82 ± 0.14	105.14 ± 4.62	24.23 ± 1.23
L-Cystine	2.36 ± 0.73	0.35 ± 0.03	2.46 ± 0.54
L-Methionine	11.19 ± 0.21	58.20 ± 1.75	16.39 ± 0.36
L-Isoleucine	104.12 ± 0.41	168.15 ± 4.56	40.07 ± 0.45
L-Leucine	43.77 ± 0.36	94.14 ± 2.36	17.09 ± 0.50
L-Tyrosine	162.88 ± 10.94	ND	38.75 ± 0.61
β-Alanine	29.41 ± 0.21	79.61 ± 1.25	14.30 ± 0.45
L-Homocystine	189.05 ± 8.50	668.55 ± 4.66	83.38 ± 0.86
γ-Amino-n-butyric acid	158.99 ± 7.64	231.14 ± 1.35	42.32 ± 0.64
Ethanolamine	108.29 ± 3.50	448.94 ± 4.25	20.58 ± 0.03
δ-Hydroxylysine	0.10 ± 0.02	89.18 ± 0.58	2.43 ± 0.05
Ornithine	5.48 ± 0.14	75.49 ± 0.25	1.73 ± 0.04
1-Methylhistidine	8.96 ± 0.65	43.87 ± 0.36	13.21 ± 0.10
L-Histidine	9.47 ± 1.58	26.47 ± 1.27	2.77 ± 0.05
L-Arginine	16.84 ± 0.24	0.28 ± 0.04	19.97 ± 1.25
Total	1743.51 ± 49.81	4402.50 ± 62.96	790.83 ± 20.27

ND: not detected.