Mineral Properties and Dietary Value of Raw and Processed Stinging Nettle (Urtica dioica L.)

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 ± 0.17^b	1.13 ± 0.20^ab	1.30 ± 0.10^a	1.39 ± 0.06^a	1.04 ± 0.08^a	1.04 ± 0.08^a	1.06 ± 0.09^a	0.97 ± 0.05^a
Leucine	1.65 ± 0.27^b	2.09 ± 0.033^ab	2.37 ± 0.18^a	2.56 ± 0.18^a	1.79 ± 0.38^a	1.91 ± 0.06^a	1.91 ± 0.08^a	1.75 ± 0.03^a
Lysine	1.11 ± 0.21^a	1.37 ± 0.11^a	1.37 ± 0.30^a	1.48 ± 0.17^a	1.16 ± 0.38^a	1.33 ± 0.20^a	1.19 ± 0.30^a	1.10 ± 0.19^a
Methionine	0.24 ± 0.05^a	0.31 ± 0.04^a	0.33 ± 0.05^a	0.35 ± 0.06^a	0.23 ± 0.15^a	0.19 ± 0.13^a	0.17 ± 0.07^a	0.20 ± 0.13^a
Tyrosine	0.75 ± 0.13^b	0.95 ± 0.13^ab	1.11 ± 0.10^ab	1.18 ± 0.14^a	0.97 ± 0.20^a	0.90 ± 0.10^a	0.93 ± 0.12^a	0.91 ± 0.13^a
Phenylalanine	1.03 ± 0.19^b	1.27 ± 0.17^ab	1.43 ± 0.15^a	1.51 ± 0.03^a	1.15 ± 0.23^a	1.14 ± 0.05^a	1.13 ± 0.04^a	1.06 ± 0.04^a
Threonine	1.00 ± 0.17^a	1.08 ± 0.05^a	1.12 ± 0.15^a	1.24 ± 0.08^a	1.03 ± 0.24^a	0.75 ± 0.07^a	0.84 ± 0.11^a	0.75 ± 0.14^a
Valine	1.11 ± 0.19^b	1.40 ± 0.23^ab	1.60 ± 0.11^a	1.72 ± 0.16^a	1.30 ± 0.24^a	1.28 ± 0.12^a	1.32 ± 0.15^a	1.22 ± 0.10^a
Histidine	0.42 ± 0.09^b	0.53 ± 0.11^ab	0.64 ± 0.06^ab	0.68 ± 0.11^a	0.32 ± 0.15^a	0.30 ± 0.12^a	0.37 ± 0.08^a	0.22 ± 0.12^a
Total essential amino acids	8.23 ± 1.36^b	10.13 ± 1.39^ab	11.26 ± 1.00^a	12.11 ± 1.60^a	8.95 ± 2.14^a	8.83 ± 0.39^a	8.93 ± 0.29^a	8.20 ± 0.59^a
Arginine	1.22 ± 0.21^b	1.57 ± 0.27^ab	1.79 ± 0.16^a	1.97 ± 0.14^a	1.55 ± 0.42^a	1.43 ± 0.26^a	1.56 ± 0.21^a	1.52 ± 0.24^a
Aspartic acid + asparagine	0.85 ± 0.32^a	1.01 ± 0.25^a	0.88 ± 0.40^a	1.01 ± 0.04^a	0.60 ± 0.37^a	0.47 ± 0.09^a	0.49 ± 0.10^a	0.39 ± 0.14^a
Glutamic acid + glutamine	1.69 ± 0.39^a	2.13 ± 0.19^a	1.97 ± 0.62^a	2.22 ± 0.26^a	1.49 ± 0.72^a	1.25 ± 0.26^a	1.42 ± 0.13^a	1.14 ± 0.27^a
Serine	0.85 ± 0.14^b	1.06 ± 0.15^ab	1.14 ± 0.13^ab	1.26 ± 0.10^a	1.00 ± 0.29^a	0.82 ± 0.12^a	0.96 ± 0.15^a	0.82 ± 0.20^a
Proline	0.90 ± 0.15^b	1.11 ± 0.17^ab	1.31 ± 0.13^ab	1.41 ± 0.20^a	1.24 ± 0.17^a	1.06 ± 0.22^a	1.19 ± 0.28^a	1.07 ± 0.16^a
Glycine	0.92 ± 0.15^b	1.13 ± 0.16^ab	1.26 ± 0.10^ab	1.39 ± 0.17^a	1.14 ± 0.23^a	0.98 ± 0.22^a	1.12 ± 0.22^a	0.97 ± 0.12^a
Alanine	1.20 ± 0.19^b	1.40 ± 0.13^ab	1.54 ± 0.11^ab	1.66 ± 0.16^a	1.54 ± 0.29^a	1.24 ± 0.22^a	1.38 ± 0.26^a	1.21 ± 0.14^a
Total amino acids	17.46 ± 2.88^b	21.58 ± 3.40^ab	22.87 ± 2.21^ab	24.76 ± 0.96^a	19.40 ± 5.00^a	17.77 ± 1.83^a	18.73 ± 1.44^a	16.97 ± 1.63^a
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).