Research Article

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

Table 2

Proximate composition, vitamins, minerals, and fatty acid profile of raw and processed stinging nettle (Urtica dioica L.) shoots harvested from field plots in the fall of 2011 and spring of 2012.

Fall 2011Spring 2012
RawBlanchedCookedCooked + saltRawBlanchedCookedCooked + salt

Proximate analysis
 Moisture (%)89.0 ± 1.4a87.2 ± 0.9a87.7 ± 0.7a88.6 ± 0.5a75.1 ± 1.5c84.6 ± 2.5b85.6 ± 0.8b91.7 ± 0.9a
 Protein (%) 3.7 ± 0.5a 3.6 ± 0.4ab 3.6 ± 0.3a 2.7 ± 0.2b 6.3 ± 0.3a 4.1 ± 0.2b 3.8 ± 0.3b 2.2 ± 0.2c
 Fat (%) 0.6 ± 0.1a 0.4 ± 0.1b 0.4 ± 0.0b 0.2 ± 0.0b 1.4 ± 0.3a 1.1 ± 0.1a 1.1 ± 0.2a 0.6 ± 0.1b
 Ash (%) 2.1 ± 0.3a 1.8 ± 0.3ab 1.5 ± 0.3b 1.5 ± 0.1b 3.4 ± 0.2a 1.4 ± 0.1b 1.2 ± 0.1c 1.0 ± 0.1c
 Fiber, total dietary (%) 6.4 ± 0.4a 4.2 ± 0.1b 3.5 ± 0.3c 3.6 ± 0.3bc 9.7 ± 1.0a 5.4 ± 0.9b 4.9 ± 1.0b 4.2 ± 0.2c
 Carbohydrates, total (%) 7.1 ± 1.7a 6.6 ± 1.4ab 6.3 ± 0.8b 6.2 ± 1.2b16.5 ± 1.6a 8.9 ± 0.7b 8.1 ± 1.1b 4.2 ± 0.6c
 Other carbohydrates (%) 2.7 ± 0.2ab 2.9 ± 0.3a 2.5 ± 0.1b 2.7 ± 0.1a 6.2 ± 1.0a 3.5 ± 0.7b 3.3 ± 0.5b 2.0 ± 0.1c
 Calories, total (kcal/100 g)45.7 ± 3.1a42.6 ± 2.1a44.7 ± 2.5a36.5 ± 2.3b99.7 ± 2.5a62.0 ± 1.0b57.3 ± 1.5c32.0 ± 1.0d
 Calories from fat (kcal/100 g) 5.0 ± 1.0a 4.3 ± 0.6ab 2.7 ± 0.5bc 2.3 ± 0.6c12.3 ± 1.6a10.0 ± 1.0ab 8.7 ± 3.1b 4.0 ± 1.0c
Vitamins and minerals
 Vitamin A, total (IU/100 g)4935 ± 104a4851 ± 56a4548 ± 53b4362 ± 78b11403 ± 1333a6470 ± 222bc6021 ± 90c7872 ± 354b
 Vitamin A, as β-carotene (IU/100 g)5035 ± 213a4689 ± 37b4549 ± 130b4062 ± 39c 7860 ± 460a4811 ± 88b5028 ± 65b4154 ± 148c
 Vitamin C (mg/100 g)1.1 ± 0.1a0.6 ± 0.1b0.6 ± 0.1b 0.5 ± 0.1b 0.5 ± 0.0a0.5 ± 0.0a0.5 ± 0.0a 0.5 ± 0.0a
 Calcium (mg/100 g) 278 ± 9c441 ± 12a376 ± 9ab 318 ± 52bc 788 ± 41a 464 ± 10b430 ± 10b 316 ± 7c
 Iron (mg/100 g)1.2 ± 0.1c1.8 ± 0.2b2.6 ± 0.1a 2.5 ± 0.3a3.4 ± 0.3a2.1 ± 0.2b2.1 ± 0.3b 1.6 ± 0.1c
 Sodium (mg/100 g) 5.7 ± 0.1b6.3 ± 0.4b6.5 ± 0.3b87.7 ± 6.0a5.5 ± 0.6b7.0 ± 0.2b 6.7 ± 0.2b81.1 ± 2.9a
Fatty acid profile
 Saturated fat (%)35.5 ± 2.6a25.7 ± 2.5b c21.7 ± 1.9d32.7 ± 2.8a16.5 ± 1.5bc17.3 ± 1.2b15.7 ± 1.4c
 Monounsaturated (%) 2.7 ± 0.2c 3.3 ± 0.2a 4.8 ± 0.3a 3.2 ± 0.1b 7.5 ± 0.6a 5.3 ± 0.3b 5.8 ± 1.1b 4.6 ± 0.2c
 Polyunsaturated (%)61.8 ± 3.5c71.0 ± 2.0b71.6 ± 1.2c75.1 ± 1.9a59.8 ± 2.7d78.2 ± 4.4b76.9 ± 2.5c79.7 ± 2.6a
 Cholesterol (mg/100 g) 1.0 ± 0.0a1.0 ± 0.0a 1.0 ± 0.0a 1.0 ± 0.0a 1.0 ± 0.0a 1.0 ± 0.0a1.0 ± 0.0a 1.0 ± 0.0a

Mean ( ) ± standard deviation. Values within a year followed by different letters are significantly different at (Tukey’s HSD).