Table 4.
Amino acid content in raw and processed stinging nettle (Urtica dioica L.) shoots harvested from field plots in the fall of 2011 and spring of 2012.
Amino acid (g/100 g) | Fall 2011 | Spring 2012 | ||||||
---|---|---|---|---|---|---|---|---|
Raw | Blanched | Cooked | Cooked + salt | Raw | Blanched | Cooked | Cooked + salt | |
Isoleucine | 0.90 ± 0.17b | 1.13 ± 0.20ab | 1.30 ± 0.10a | 1.39 ± 0.06a | 1.04 ± 0.08a | 1.04 ± 0.08a | 1.06 ± 0.09a | 0.97 ± 0.05a |
Leucine | 1.65 ± 0.27b | 2.09 ± 0.033ab | 2.37 ± 0.18a | 2.56 ± 0.18a | 1.79 ± 0.38a | 1.91 ± 0.06a | 1.91 ± 0.08a | 1.75 ± 0.03a |
Lysine | 1.11 ± 0.21a | 1.37 ± 0.11a | 1.37 ± 0.30a | 1.48 ± 0.17a | 1.16 ± 0.38a | 1.33 ± 0.20a | 1.19 ± 0.30a | 1.10 ± 0.19a |
Methionine | 0.24 ± 0.05a | 0.31 ± 0.04a | 0.33 ± 0.05a | 0.35 ± 0.06a | 0.23 ± 0.15a | 0.19 ± 0.13a | 0.17 ± 0.07a | 0.20 ± 0.13a |
Tyrosine | 0.75 ± 0.13b | 0.95 ± 0.13ab | 1.11 ± 0.10ab | 1.18 ± 0.14a | 0.97 ± 0.20a | 0.90 ± 0.10a | 0.93 ± 0.12a | 0.91 ± 0.13a |
Phenylalanine | 1.03 ± 0.19b | 1.27 ± 0.17ab | 1.43 ± 0.15a | 1.51 ± 0.03a | 1.15 ± 0.23a | 1.14 ± 0.05a | 1.13 ± 0.04a | 1.06 ± 0.04a |
Threonine | 1.00 ± 0.17a | 1.08 ± 0.05a | 1.12 ± 0.15a | 1.24 ± 0.08a | 1.03 ± 0.24a | 0.75 ± 0.07a | 0.84 ± 0.11a | 0.75 ± 0.14a |
Valine | 1.11 ± 0.19b | 1.40 ± 0.23ab | 1.60 ± 0.11a | 1.72 ± 0.16a | 1.30 ± 0.24a | 1.28 ± 0.12a | 1.32 ± 0.15a | 1.22 ± 0.10a |
Histidine | 0.42 ± 0.09b | 0.53 ± 0.11ab | 0.64 ± 0.06ab | 0.68 ± 0.11a | 0.32 ± 0.15a | 0.30 ± 0.12a | 0.37 ± 0.08a | 0.22 ± 0.12a |
Total essential amino acids | 8.23 ± 1.36b | 10.13 ± 1.39ab | 11.26 ± 1.00a | 12.11 ± 1.60a | 8.95 ± 2.14a | 8.83 ± 0.39a | 8.93 ± 0.29a | 8.20 ± 0.59a |
Arginine | 1.22 ± 0.21b | 1.57 ± 0.27ab | 1.79 ± 0.16a | 1.97 ± 0.14a | 1.55 ± 0.42a | 1.43 ± 0.26a | 1.56 ± 0.21a | 1.52 ± 0.24a |
Aspartic acid + asparagine | 0.85 ± 0.32a | 1.01 ± 0.25a | 0.88 ± 0.40a | 1.01 ± 0.04a | 0.60 ± 0.37a | 0.47 ± 0.09a | 0.49 ± 0.10a | 0.39 ± 0.14a |
Glutamic acid + glutamine | 1.69 ± 0.39a | 2.13 ± 0.19a | 1.97 ± 0.62a | 2.22 ± 0.26a | 1.49 ± 0.72a | 1.25 ± 0.26a | 1.42 ± 0.13a | 1.14 ± 0.27a |
Serine | 0.85 ± 0.14b | 1.06 ± 0.15ab | 1.14 ± 0.13ab | 1.26 ± 0.10a | 1.00 ± 0.29a | 0.82 ± 0.12a | 0.96 ± 0.15a | 0.82 ± 0.20a |
Proline | 0.90 ± 0.15b | 1.11 ± 0.17ab | 1.31 ± 0.13ab | 1.41 ± 0.20a | 1.24 ± 0.17a | 1.06 ± 0.22a | 1.19 ± 0.28a | 1.07 ± 0.16a |
Glycine | 0.92 ± 0.15b | 1.13 ± 0.16ab | 1.26 ± 0.10ab | 1.39 ± 0.17a | 1.14 ± 0.23a | 0.98 ± 0.22a | 1.12 ± 0.22a | 0.97 ± 0.12a |
Alanine | 1.20 ± 0.19b | 1.40 ± 0.13ab | 1.54 ± 0.11ab | 1.66 ± 0.16a | 1.54 ± 0.29a | 1.24 ± 0.22a | 1.38 ± 0.26a | 1.21 ± 0.14a |
Total amino acids | 17.46 ± 2.88b | 21.58 ± 3.40ab | 22.87 ± 2.21ab | 24.76 ± 0.96a | 19.40 ± 5.00a | 17.77 ± 1.83a | 18.73 ± 1.44a | 16.97 ± 1.63a |
Dry matter (g/100 g edible portion) | 11.0 | 12.8 | 12.3 | 11.4 | 14.9 | 15.4 | 14.4 | 8.3 |
aMean (n = 3) ± standard deviation. Row values followed by different letters within season are significantly different at P < 0.05 (Tukey's HSD).